WASHINGTON (AFP) - NASA unveiled Thursday a model of the massive space telescope that will replace the aging Hubble in 2013 and allow scientists to observe the formation of the first galaxies at the dawning of the universe.
The US National Aeronautics and Space Agency displayed in Washington a full-scale model of the James Webb (news, bio, voting record) Space Telescope, which scientists hope will peer back to the first stars after the "Big Bang" and the formation of solar systems capable of hosting life.
JWST, a joint project of the US, European and Canadian space agencies, will be three times bigger than Hubble, with a hexagonal mirror 6.5 meters (21.3 feet) in diameter and five-layer sunshield the size of a tennis court
The probe being built by Northrop Grumman Corp. will include 10 new technologies, including an infrared camera and a spectrometer kept at an extremely low temperature for optimum performance. The telescope is expected to have a 10-year lifespan.
The model was put on display Thursday in front of Washington's National Air and Space Museum.
Launched 17 years ago, Hubble revolutionized astronomy by peering deep into the universe, beaming back dazzling images free of the distortions from Earth's atmosphere.
Orbiting 575 kilometers (360 miles) above Earth, the Hubble has enabled scientists to better measure the age and origins of the universe, observe distant supernovas, and identify and study bodies in and outside the solar system.
While Hubble was able to peer back to one billion years after the Big Bang, the new telescope, with mirrors that will capture six times more light than its predecessor, will look even further into the origins of the universe, officials said.
"Clearly we need a much bigger telescope to go back much further in time to see the very birth of the universe," Edward Weiler, director of NASA's Goddard Space Flight Center, told a news conference.
Hubble, along with space telescopes Chandra and Spitzer, have shown that the universe is hiding many mysteries, but they are unable to solve them, said Matt Mountain, director of the Space Telescope Science Institute near Washington.
"We cannot penetrate the darkness of the time when the first galaxies were born," Mountain said.
The current telescopes are also unable to provide answers about black holes and the enigmatic dark matter, he said.
With its more powerful mirrors, the new telescope "for the first time will send images from that dark age, high resolution pictures," he said.
The 4.5 billion dollar James Webb Space Telescope will be folded to fit inside a European Ariane V rocket in 2013 and will unfurl 1.5 million kilometers (0.93 million miles) from Earth.
NASA plans to launch a space shuttle mission next year to upgrade and maintain Hubble in order to keep it operational through 2013.
Without a repair mission, the telescope would shut down in 2009 or even earlier, dealing a blow to scientists who have relied on Hubble's images to better understand the universe.
James Webb Space Telescope
by Jean-Louis Santini
Thursday, May 17, 2007
Tuesday, May 08, 2007
Israeli archaeologist says Herod's tomb found
JERUSALEM (AFP) - An Israeli archaeologist said on Tuesday that the tomb of King Herod, famed for expanding the Jewish second temple during his reign in the first century BC, had been discovered in the occupied West Bank.
Pieces of an elaborate sarcophagus believed to contain Herod's remains were found three weeks ago, Ehud Netzer, professor of archaeology at Hebrew University, told a news conference.
"Three weeks ago we found the sarcophagus and we knew that it was it," said Netzer, who led the digs and has been working at the site since 1972.
The tomb was located at Herodium, a mesa rising more than 750 metres (2,475 feet) above sea level some 12 kilometres (7.5 miles) south of Jerusalem in the West Bank, Netzer said.
Herod built a palace on the flattened hilltop and was thought to have been buried there, but years of excavations failed to find the burial site.
"The location and unique nature of the findings, as well as the historical record, leave no doubt that this was Herod's burial site," Netzer said, adding that no inscriptions have yet been found.
The sarcophagus was discovered on the northeast slope of the mesa, where archaeological excavation began in August 2006.
It "was broken into hundreds of pieces, no doubt deliberately," Netzer said, adding that it appeared to have been destroyed between 66 and 72 AD during the first Jewish revolt against the Romans.
"It is an important discovery, first of all because Herod is well known," he said. "Secondly, because Herod is a personality that is important to the Christians -- he is mentioned many times in the New Testament.
"Thirdly, Herodium is a wonderful building that Herod left us," he added.
Herod, sometimes called Herod the Great, was appointed king of Judea by the Romans in around 40 BC. He greatly expanded the Jewish second temple and ordered building works in Caesaeria, Jericho and at the hilltop fortress of Masada overlooking the Dead Sea.
The discovery is likely to spark political fallout in a region where archaeological finds inevitably become linked to the Israeli-Palestinian conflict, and any claims that appear to strengthen one side's connection to the land are viewed suspiciously by the other.
After the news conference, Shaul Goldstein, an official with the Gush Etzion Jewish settlement near the Herodium site, told army radio that the find "constitutes new proof of a connection between Gush Etzion and the Jewish people and Jerusalem."
He called on the government to name Herodium "a national and religious site."
Palestinian tourism minister Khulud Dwaibess, who oversees archaeological sites, told AFP that a team of Palestinian archaeologists was due to inspect the site and that her ministry would not comment until after receiving their report.
by Delphine Matthieussent
Pieces of an elaborate sarcophagus believed to contain Herod's remains were found three weeks ago, Ehud Netzer, professor of archaeology at Hebrew University, told a news conference.
"Three weeks ago we found the sarcophagus and we knew that it was it," said Netzer, who led the digs and has been working at the site since 1972.
The tomb was located at Herodium, a mesa rising more than 750 metres (2,475 feet) above sea level some 12 kilometres (7.5 miles) south of Jerusalem in the West Bank, Netzer said.
Herod built a palace on the flattened hilltop and was thought to have been buried there, but years of excavations failed to find the burial site.
"The location and unique nature of the findings, as well as the historical record, leave no doubt that this was Herod's burial site," Netzer said, adding that no inscriptions have yet been found.
The sarcophagus was discovered on the northeast slope of the mesa, where archaeological excavation began in August 2006.
It "was broken into hundreds of pieces, no doubt deliberately," Netzer said, adding that it appeared to have been destroyed between 66 and 72 AD during the first Jewish revolt against the Romans.
"It is an important discovery, first of all because Herod is well known," he said. "Secondly, because Herod is a personality that is important to the Christians -- he is mentioned many times in the New Testament.
"Thirdly, Herodium is a wonderful building that Herod left us," he added.
Herod, sometimes called Herod the Great, was appointed king of Judea by the Romans in around 40 BC. He greatly expanded the Jewish second temple and ordered building works in Caesaeria, Jericho and at the hilltop fortress of Masada overlooking the Dead Sea.
The discovery is likely to spark political fallout in a region where archaeological finds inevitably become linked to the Israeli-Palestinian conflict, and any claims that appear to strengthen one side's connection to the land are viewed suspiciously by the other.
After the news conference, Shaul Goldstein, an official with the Gush Etzion Jewish settlement near the Herodium site, told army radio that the find "constitutes new proof of a connection between Gush Etzion and the Jewish people and Jerusalem."
He called on the government to name Herodium "a national and religious site."
Palestinian tourism minister Khulud Dwaibess, who oversees archaeological sites, told AFP that a team of Palestinian archaeologists was due to inspect the site and that her ministry would not comment until after receiving their report.
by Delphine Matthieussent
Astronomers spot exploding faraway star
WASHINGTON - A massive exploding faraway star — the brightest supernova astronomers have ever seen — has scientists wondering whether a similar celestial fireworks show may light up the sky much closer to Earth sometime soon.
The discovery, announced Monday by NASA, drew oohs and aahs for months from the handful of astronomers who peered through telescopes to see the fuzzy remnants of the spectacular explosion after it was first spotted last fall.
Using a variety of Earth and space telescopes, astronomers found a giant exploding star that they figure has shined about five times brighter than any of the hundreds of supernovae ever seen before, said discovery team leader Nathan Smith of the University of California at Berkeley. The discovery was first made last September by a graduate student in Texas.
"This one is way above anything else," Smith told The Associated Press. "It's really astonishing."
Smith said the star, SN2006gy, "is a special kind of supernova that has never been seen before." He called the star "freakily massive" at 150 times the mass of the sun.
Observations from the Chandra X-ray telescope helped show that it didn't become a black hole like other supernovae and skipped a stage of star death.
Unlike other exploding stars, which peak at brightness for a couple of weeks at most, this supernova, peaked for 70 days, according to NASA. And it has been shining at levels brighter than other supernovae for several months, Smith said.
And even at 240 million light years away, this star in a distant galaxy does suggest that a similar and relatively nearby star — one 44 quadrillion miles away — might blow in similar fashion any day now or 50,000 years from now, Smith said. It wouldn't threaten Earth, but it would be so bright that people could read by it at night, said University of California at Berkeley astronomer David Pooley. However, it would only be visible to people in the Southern Hemisphere, he said.
By SETH BORENSTEIN, AP Science Writer
The discovery, announced Monday by NASA, drew oohs and aahs for months from the handful of astronomers who peered through telescopes to see the fuzzy remnants of the spectacular explosion after it was first spotted last fall.
Using a variety of Earth and space telescopes, astronomers found a giant exploding star that they figure has shined about five times brighter than any of the hundreds of supernovae ever seen before, said discovery team leader Nathan Smith of the University of California at Berkeley. The discovery was first made last September by a graduate student in Texas.
"This one is way above anything else," Smith told The Associated Press. "It's really astonishing."
Smith said the star, SN2006gy, "is a special kind of supernova that has never been seen before." He called the star "freakily massive" at 150 times the mass of the sun.
Observations from the Chandra X-ray telescope helped show that it didn't become a black hole like other supernovae and skipped a stage of star death.
Unlike other exploding stars, which peak at brightness for a couple of weeks at most, this supernova, peaked for 70 days, according to NASA. And it has been shining at levels brighter than other supernovae for several months, Smith said.
And even at 240 million light years away, this star in a distant galaxy does suggest that a similar and relatively nearby star — one 44 quadrillion miles away — might blow in similar fashion any day now or 50,000 years from now, Smith said. It wouldn't threaten Earth, but it would be so bright that people could read by it at night, said University of California at Berkeley astronomer David Pooley. However, it would only be visible to people in the Southern Hemisphere, he said.
By SETH BORENSTEIN, AP Science Writer
Friday, May 04, 2007
Mercury may have molten fluid inside
WASHINGTON - Researchers have cracked a mystery at the core of Mercury — and say there's molten fluid inside the tiny planet. They did it by using the same trick as cooks who want to know if an egg is raw or hard-boiled.
The finding helps explain the unexpected discovery several years ago that Mercury has a small magnetic field.
The discovery of the magnetic field by the Mariner 10 spacecraft puzzled scientists, who believed that because of its small size the planet's core had long ago solidified.
But the most common explanation for a magnetic field is a molten interior, such as on Earth. The Moon and Mars, for example, show evidence only of ancient magnetic fields.
The Messenger spacecraft is on its way to Mercury and is expected to arrive next year, but in the meantime researchers led by Jean-Luc Margot, an assistant professor of astronomy at Cornell University, launched their own attempt to learn about the planet's core.
Cooks wondering if an egg is raw or has been cooked have used a simple trick for many years — spin the egg. A hard-boiled egg with a solid interior will spin smoothly, a raw one with a liquid center will wobble.
Of course, Mercury may be small, but they obviously couldn't spin it themselves.
Instead, they closely studied its movements using telescopes in California, Puerto Rico and West Virginia.
They sent powerful radar signals at the planet, then received the echo, which appeared as a unique pattern of speckles reflecting the roughness of the planet's surface, at widely separated locations.
By measuring how long it took for a particular speckle pattern to reproduce at different locations they were able to calculate Mercury's spin rate with an accuracy of one part in 100,000.
The observations, conducted over five years, allowed the scientists to calculate twists in Mercury's spin, called librations, caused by the effect of the sun's gravity. The magnitude of the librations was twice what would be expected for a completely solid body, they concluded. But it matched what would be expected for an object whose outer core is molten and not forced to rotate along with its shell.
Sean C. Solomon of the Carnegie Institution of Washington, who was not part of the research team, said in a commentary that the measurements "constitute a triumph" of theoretical ideas developed in the past.
By RANDOLPH E. SCHMID, AP Science Writer
The finding helps explain the unexpected discovery several years ago that Mercury has a small magnetic field.
The discovery of the magnetic field by the Mariner 10 spacecraft puzzled scientists, who believed that because of its small size the planet's core had long ago solidified.
But the most common explanation for a magnetic field is a molten interior, such as on Earth. The Moon and Mars, for example, show evidence only of ancient magnetic fields.
The Messenger spacecraft is on its way to Mercury and is expected to arrive next year, but in the meantime researchers led by Jean-Luc Margot, an assistant professor of astronomy at Cornell University, launched their own attempt to learn about the planet's core.
Cooks wondering if an egg is raw or has been cooked have used a simple trick for many years — spin the egg. A hard-boiled egg with a solid interior will spin smoothly, a raw one with a liquid center will wobble.
Of course, Mercury may be small, but they obviously couldn't spin it themselves.
Instead, they closely studied its movements using telescopes in California, Puerto Rico and West Virginia.
They sent powerful radar signals at the planet, then received the echo, which appeared as a unique pattern of speckles reflecting the roughness of the planet's surface, at widely separated locations.
By measuring how long it took for a particular speckle pattern to reproduce at different locations they were able to calculate Mercury's spin rate with an accuracy of one part in 100,000.
The observations, conducted over five years, allowed the scientists to calculate twists in Mercury's spin, called librations, caused by the effect of the sun's gravity. The magnitude of the librations was twice what would be expected for a completely solid body, they concluded. But it matched what would be expected for an object whose outer core is molten and not forced to rotate along with its shell.
Sean C. Solomon of the Carnegie Institution of Washington, who was not part of the research team, said in a commentary that the measurements "constitute a triumph" of theoretical ideas developed in the past.
By RANDOLPH E. SCHMID, AP Science Writer
Friday, April 27, 2007
Astronomers Find First Earth-like Planet in Habitable Zone
This exoplanet - as astronomers call planets around a star other than the Sun - is the smallest ever found up to now [1] and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581 [2], is smaller and colder than the Sun - and thus less luminous - the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid! The planet's name is Gliese 581 c.
"We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid," explains Stéphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result. "Moreover, its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky - like our Earth - or fully covered with oceans," he adds.
"Liquid water is critical to life as we know it," avows Xavier Delfosse, a member of the team from Grenoble University (France). "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."
The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra ("the Scales"). It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class.
"Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun," emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method [3], the most successful in detecting exoplanets.
Two years ago, the same team of astronomers already found a planet around Gliese 581 (see ESO 30/05). With a mass of 15 Earth-masses, i.e. similar to that of Neptune, it orbits its host star in 5.4 days. At the time, the astronomers had already seen hints of another planet. They therefore obtained a new set of measurements and found the new super-Earth, but also clear indications for another one, an 8 Earth-mass planet completing an orbit in 84 days. The planetary system surrounding Gliese 581 contains thus no fewer than 3 planets of 15 Earth masses or less, and as such is a quite remarkable system.
The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another 'Trio of Neptunes' (ESO 18/06, see also ESO 22/04).
The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs.
"HARPS is a unique planet hunting machine," says Michel Mayor, from Geneva Observatory, and HARPS Principal Investigator. "Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!"
HARPS is also very efficient in finding planetary systems, where tiny signals have to be uncovered. The two systems known to have three low mass planets - HD 69830 and Gl 581 - were discovered by HARPS.
"And we are confident that, given the results obtained so far, finding a planet with the mass of the Earth around a red dwarf is within reach," affirms Mayor.
More Information
This research is reported in a paper submitted as a Letter to the Editor of Astronomy and Astrophysics ("The HARPS search for southern extra-solar planets : XI. An habitable super-Earth (5 MEarth) in a 3-planet system", by S. Udry et al.) The paper is available from http://obswww.unige.ch/~udry/udry_preprint.pdf.
The team is composed of Stéphane Udry, Michel Mayor, Christophe Lovis, Francesco Pepe, and Didier Queloz (Geneva Observatory, Switzerland), Xavier Bonfils (Lisbonne Observatory, Portugal), Xavier Delfosse, Thierry Forveille, and C.Perrier (LAOG, Grenoble, France), François Bouchy (Institut d'Astrophysique de Paris, France), and Jean-Luc Bertaux (Service d'Aéronomie du CNRS, France)
Notes
[1]: Using the radial velocity method, astronomers can only obtain a minimum mass (as it is multiplied by the sine of the inclination of the orbital plane to the line of sight, which is unknown). From a statistical point of view, this is however often close to the real mass of the system. Two other systems have a mass close to this. The icy planet around OGLE-2005-BLG-390L, discovered by microlensing with a network of telescopes including one at La Silla (ESO 03/06), has a (real) mass of 5.5 Earth masses. It, however, orbits much farther from its small host star than the present one and is hence much colder. The other is one of the planets surrounding the star Gliese 876. It has a minimum mass of 5.89 Earth masses (and a probable real mass of 7.53 Earth masses) and completes an orbit in less than 2 days, making it too hot for liquid water to be present.
[2]: Gl 581, or Gliese 581, is the 581th entry in the Gliese Catalogue, which lists all known stars within 25 parsecs (81.5 light years) of the Sun. It was originally compiled by Gliese and published in 1969, and later updated by Gliese and Jahreiss in 1991.
[3]: This fundamental observational method is based on the detection of variations in the velocity of the central star, due to the changing direction of the gravitational pull from an (unseen) exoplanet as it orbits the star. The evaluation of the measured velocity variations allows deducing the planet's orbit, in particular the period and the distance from the star, as well as a minimum mass.
Contact
Stéphane Udry, Michel Mayor
Observatory of Geneva University, Switzerland
Phone: +41 22 379 22 00
Email: Stephane.Udry (at) obs.unige.ch, Michel.Mayor (at) obs.unige.ch
Xavier Delfosse, Thierry Forveille
LAOG, France
Phone: +33 476 51 42 06
Email: Xavier.Delfosse (at) obs.ujf-grenoble.fr, Thierry.Forveille (at) obs.ujf-grenoble.fr
Xavier Bonfils
Lisbonne Observatory, Portugal
Phone: +351 21 361 67 43
Email: xavier.bonfils (at) oal.ul.pt
The Dwarf Carried Other Worlds Too!
Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.
"We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid," explains Stéphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result. "Moreover, its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky - like our Earth - or fully covered with oceans," he adds.
"Liquid water is critical to life as we know it," avows Xavier Delfosse, a member of the team from Grenoble University (France). "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."
The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra ("the Scales"). It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class.
"Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun," emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method [3], the most successful in detecting exoplanets.
Two years ago, the same team of astronomers already found a planet around Gliese 581 (see ESO 30/05). With a mass of 15 Earth-masses, i.e. similar to that of Neptune, it orbits its host star in 5.4 days. At the time, the astronomers had already seen hints of another planet. They therefore obtained a new set of measurements and found the new super-Earth, but also clear indications for another one, an 8 Earth-mass planet completing an orbit in 84 days. The planetary system surrounding Gliese 581 contains thus no fewer than 3 planets of 15 Earth masses or less, and as such is a quite remarkable system.
The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another 'Trio of Neptunes' (ESO 18/06, see also ESO 22/04).
The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs.
"HARPS is a unique planet hunting machine," says Michel Mayor, from Geneva Observatory, and HARPS Principal Investigator. "Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!"
HARPS is also very efficient in finding planetary systems, where tiny signals have to be uncovered. The two systems known to have three low mass planets - HD 69830 and Gl 581 - were discovered by HARPS.
"And we are confident that, given the results obtained so far, finding a planet with the mass of the Earth around a red dwarf is within reach," affirms Mayor.
More Information
This research is reported in a paper submitted as a Letter to the Editor of Astronomy and Astrophysics ("The HARPS search for southern extra-solar planets : XI. An habitable super-Earth (5 MEarth) in a 3-planet system", by S. Udry et al.) The paper is available from http://obswww.unige.ch/~udry/udry_preprint.pdf.
The team is composed of Stéphane Udry, Michel Mayor, Christophe Lovis, Francesco Pepe, and Didier Queloz (Geneva Observatory, Switzerland), Xavier Bonfils (Lisbonne Observatory, Portugal), Xavier Delfosse, Thierry Forveille, and C.Perrier (LAOG, Grenoble, France), François Bouchy (Institut d'Astrophysique de Paris, France), and Jean-Luc Bertaux (Service d'Aéronomie du CNRS, France)
Notes
[1]: Using the radial velocity method, astronomers can only obtain a minimum mass (as it is multiplied by the sine of the inclination of the orbital plane to the line of sight, which is unknown). From a statistical point of view, this is however often close to the real mass of the system. Two other systems have a mass close to this. The icy planet around OGLE-2005-BLG-390L, discovered by microlensing with a network of telescopes including one at La Silla (ESO 03/06), has a (real) mass of 5.5 Earth masses. It, however, orbits much farther from its small host star than the present one and is hence much colder. The other is one of the planets surrounding the star Gliese 876. It has a minimum mass of 5.89 Earth masses (and a probable real mass of 7.53 Earth masses) and completes an orbit in less than 2 days, making it too hot for liquid water to be present.
[2]: Gl 581, or Gliese 581, is the 581th entry in the Gliese Catalogue, which lists all known stars within 25 parsecs (81.5 light years) of the Sun. It was originally compiled by Gliese and published in 1969, and later updated by Gliese and Jahreiss in 1991.
[3]: This fundamental observational method is based on the detection of variations in the velocity of the central star, due to the changing direction of the gravitational pull from an (unseen) exoplanet as it orbits the star. The evaluation of the measured velocity variations allows deducing the planet's orbit, in particular the period and the distance from the star, as well as a minimum mass.
Contact
Stéphane Udry, Michel Mayor
Observatory of Geneva University, Switzerland
Phone: +41 22 379 22 00
Email: Stephane.Udry (at) obs.unige.ch, Michel.Mayor (at) obs.unige.ch
Xavier Delfosse, Thierry Forveille
LAOG, France
Phone: +33 476 51 42 06
Email: Xavier.Delfosse (at) obs.ujf-grenoble.fr, Thierry.Forveille (at) obs.ujf-grenoble.fr
Xavier Bonfils
Lisbonne Observatory, Portugal
Phone: +351 21 361 67 43
Email: xavier.bonfils (at) oal.ul.pt
The Dwarf Carried Other Worlds Too!
Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.
Wednesday, April 25, 2007
Potentially habitable planet found
WASHINGTON - For the first time astronomers have discovered a planet outside our solar system that is potentially habitable, with Earth-like temperatures, a find researchers described Tuesday as a big step in the search for "life in the universe."
The planet is just the right size, might have water in liquid form, and in galactic terms is relatively nearby at 120 trillion miles away. But the star it closely orbits, known as a "red dwarf," is much smaller, dimmer and cooler than our sun.
There's still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is known about it. And it's worth noting that scientists' requirements for habitability count Mars in that category: a size relatively similar to Earth's with temperatures that would permit liquid water. However, this is the first outside our solar system that meets those standards.
"It's a significant step on the way to finding possible life in the universe," said University of Geneva astronomer Michel Mayor, one of 11 European scientists on the team that found the planet. "It's a nice discovery. We still have a lot of questions."
The results of the discovery have not been published but have been submitted to the journal Astronomy and Astrophysics.
Alan Boss, who works at the Carnegie Institution of Washington where a U.S. team of astronomers competed in the hunt for an Earth-like planet, called it "a major milestone in this business."
The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wave lengths. Those wobbles can reveal the existence of other worlds.
What they revealed is a planet circling the red dwarf star, Gliese 581. Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun. Until a few years ago, astronomers didn't consider these stars as possible hosts of planets that might sustain life.
The discovery of the new planet, named 581 c, is sure to fuel studies of planets circling similar dim stars. About 80 percent of the stars near Earth are red dwarfs.
The new planet is about five times heavier than Earth. Its discoverers aren't certain if it is rocky like Earth or if its a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 1 1/2 times bigger than our planet. If it is an iceball, as Mayor suggests, it would be even bigger.
Based on theory, 581 c should have an atmosphere, but what's in that atmosphere is still a mystery and if it's too thick that could make the planet's surface temperature too hot, Mayor said.
However, the research team believes the average temperature to be somewhere between 32 and 104 degrees and that set off celebrations among astronomers.
Until now, all 220 planets astronomers have found outside our solar system have had the "Goldilocks problem." They've been too hot, too cold or just plain too big and gaseous, like uninhabitable Jupiter.
The new planet seems just right — or at least that's what scientists think.
"This could be very important," said NASA astrobiology expert Chris McKay, who was not part of the discovery team. "It doesn't mean there is life, but it means it's an Earth-like planet in terms of potential habitability."
Eventually astronomers will rack up discoveries of dozens, maybe even hundreds of planets considered habitable, the astronomers said. But this one — simply called "c" by its discoverers when they talk among themselves — will go down in cosmic history as No. 1.
Besides having the right temperature, the new planet is probably full of liquid water, hypothesizes Stephane Udry, the discovery team's lead author and another Geneva astronomer. But that is based on theory about how planets form, not on any evidence, he said.
"Liquid water is critical to life as we know it," co-author Xavier Delfosse of Grenoble University in France, said in a statement. "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."
Other astronomers cautioned it's too early to tell whether there is water.
"You need more work to say it's got water or it doesn't have water," said retired NASA astronomer Steve Maran, press officer for the American Astronomical Society. "You wouldn't send a crew there assuming that when you get there, they'll have enough water to get back."
The new planet's star system is a mere 20.5 light years away, making Gliese 581 one of the 100 closest stars to Earth. It's so dim, you can't see it without a telescope, but it's somewhere in the constellation Libra, which is low in the southeastern sky during the midevening in the Northern Hemisphere.
"I expect there will be planets like Earth, but whether they have life is another question," said renowned astrophysicist Stephen Hawking in an interview with The Associated Press in Orlando. "We haven't been visited by little green men yet."
Before you book your extrastellar flight to 581 c, a few caveats about how alien that world probably is: Anyone sitting on the planet would get heavier quickly, and birthdays would add up fast since it orbits its star every 13 days.
Gravity is 1.6 times as strong as Earth's so a 150-pound person would feel like 240 pounds.
But oh, the view. The planet is 14 times closer to the star it orbits. Udry figures the red dwarf star would hang in the sky at a size 20 times larger than our moon. And it's likely, but still not known, that the planet doesn't rotate, so one side would always be sunlit and the other dark.
Distance is another problem. "We don't know how to get to those places in a human lifetime," Maran said.
Two teams of astronomers, one in Europe and one in the United States, have been racing to be the first to find a planet like 581 c outside the solar system.
The European team looked at 100 different stars using a tool called HARPS (High Accuracy Radial Velocity for Planetary Searcher) to find this one planet, said Xavier Bonfils of the Lisbon Observatory, one of the co-discoverers.
Much of the effort to find Earth-like planets has focused on stars like our sun with the challenge being to find a planet the right distance from the star it orbits. About 90 percent of the time, the European telescope focused its search more on sun-like stars, Udry said.
A few weeks before the European discovery earlier this month, a scientific paper in the journal Astrobiology theorized a few days that red dwarf stars were good candidates.
"Now we have the possibility to find many more," Bonfils said.
By SETH BORENSTEIN, AP Science Writer
The planet is just the right size, might have water in liquid form, and in galactic terms is relatively nearby at 120 trillion miles away. But the star it closely orbits, known as a "red dwarf," is much smaller, dimmer and cooler than our sun.
There's still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is known about it. And it's worth noting that scientists' requirements for habitability count Mars in that category: a size relatively similar to Earth's with temperatures that would permit liquid water. However, this is the first outside our solar system that meets those standards.
"It's a significant step on the way to finding possible life in the universe," said University of Geneva astronomer Michel Mayor, one of 11 European scientists on the team that found the planet. "It's a nice discovery. We still have a lot of questions."
The results of the discovery have not been published but have been submitted to the journal Astronomy and Astrophysics.
Alan Boss, who works at the Carnegie Institution of Washington where a U.S. team of astronomers competed in the hunt for an Earth-like planet, called it "a major milestone in this business."
The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wave lengths. Those wobbles can reveal the existence of other worlds.
What they revealed is a planet circling the red dwarf star, Gliese 581. Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun. Until a few years ago, astronomers didn't consider these stars as possible hosts of planets that might sustain life.
The discovery of the new planet, named 581 c, is sure to fuel studies of planets circling similar dim stars. About 80 percent of the stars near Earth are red dwarfs.
The new planet is about five times heavier than Earth. Its discoverers aren't certain if it is rocky like Earth or if its a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 1 1/2 times bigger than our planet. If it is an iceball, as Mayor suggests, it would be even bigger.
Based on theory, 581 c should have an atmosphere, but what's in that atmosphere is still a mystery and if it's too thick that could make the planet's surface temperature too hot, Mayor said.
However, the research team believes the average temperature to be somewhere between 32 and 104 degrees and that set off celebrations among astronomers.
Until now, all 220 planets astronomers have found outside our solar system have had the "Goldilocks problem." They've been too hot, too cold or just plain too big and gaseous, like uninhabitable Jupiter.
The new planet seems just right — or at least that's what scientists think.
"This could be very important," said NASA astrobiology expert Chris McKay, who was not part of the discovery team. "It doesn't mean there is life, but it means it's an Earth-like planet in terms of potential habitability."
Eventually astronomers will rack up discoveries of dozens, maybe even hundreds of planets considered habitable, the astronomers said. But this one — simply called "c" by its discoverers when they talk among themselves — will go down in cosmic history as No. 1.
Besides having the right temperature, the new planet is probably full of liquid water, hypothesizes Stephane Udry, the discovery team's lead author and another Geneva astronomer. But that is based on theory about how planets form, not on any evidence, he said.
"Liquid water is critical to life as we know it," co-author Xavier Delfosse of Grenoble University in France, said in a statement. "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."
Other astronomers cautioned it's too early to tell whether there is water.
"You need more work to say it's got water or it doesn't have water," said retired NASA astronomer Steve Maran, press officer for the American Astronomical Society. "You wouldn't send a crew there assuming that when you get there, they'll have enough water to get back."
The new planet's star system is a mere 20.5 light years away, making Gliese 581 one of the 100 closest stars to Earth. It's so dim, you can't see it without a telescope, but it's somewhere in the constellation Libra, which is low in the southeastern sky during the midevening in the Northern Hemisphere.
"I expect there will be planets like Earth, but whether they have life is another question," said renowned astrophysicist Stephen Hawking in an interview with The Associated Press in Orlando. "We haven't been visited by little green men yet."
Before you book your extrastellar flight to 581 c, a few caveats about how alien that world probably is: Anyone sitting on the planet would get heavier quickly, and birthdays would add up fast since it orbits its star every 13 days.
Gravity is 1.6 times as strong as Earth's so a 150-pound person would feel like 240 pounds.
But oh, the view. The planet is 14 times closer to the star it orbits. Udry figures the red dwarf star would hang in the sky at a size 20 times larger than our moon. And it's likely, but still not known, that the planet doesn't rotate, so one side would always be sunlit and the other dark.
Distance is another problem. "We don't know how to get to those places in a human lifetime," Maran said.
Two teams of astronomers, one in Europe and one in the United States, have been racing to be the first to find a planet like 581 c outside the solar system.
The European team looked at 100 different stars using a tool called HARPS (High Accuracy Radial Velocity for Planetary Searcher) to find this one planet, said Xavier Bonfils of the Lisbon Observatory, one of the co-discoverers.
Much of the effort to find Earth-like planets has focused on stars like our sun with the challenge being to find a planet the right distance from the star it orbits. About 90 percent of the time, the European telescope focused its search more on sun-like stars, Udry said.
A few weeks before the European discovery earlier this month, a scientific paper in the journal Astrobiology theorized a few days that red dwarf stars were good candidates.
"Now we have the possibility to find many more," Bonfils said.
By SETH BORENSTEIN, AP Science Writer
Friday, April 20, 2007
Sun's Atmosphere Sings
Astronomers have recorded heavenly music bellowed out by the Sun's atmosphere.
Snagging orchestra seats for this solar symphony would be fruitless, however, as the frequency of the sound waves is below the human hearing threshold. While humans can make out sounds between 20 and 20,000 hertz, the solar sound waves are on the order of milli-hertz--a thousandth of a hertz.
The study, presented this week at the Royal Astronomical Society's National Astronomy Meeting in Lancashire, England, reveals that the looping magnetic fields along the Sun's outer regions, called the corona, carry magnetic sound waves in a similar manner to musical instruments such as guitars or pipe organs.
Making music
Robertus von Fay-Siebenburgen of the Solar Physics and Space Plasma Research Center at the University of Sheffield and his colleagues combined information gleaned from sun-orbiting satellites with theoretical models of solar processes, such as coronal mass ejections.
They found that explosive events at the Sun's surface appear to trigger acoustic waves that bounce back and forth between both ends of the loops, a phenomenon known as a standing wave.
"These magnetic loops are analogous to a simple guitar string," von Fay-Siebenburgen explained. "If you pluck a guitar string, you will hear the music."
In the cosmic equivalent of a guitar pick, so-called microflares at the base of loops could be plucking the magnetic loops and setting the sound waves in motion, the researchers speculate. While solar flares are the largest explosions in the solar system, microflares are a million times smaller but much more frequent; both phenomena are now thought to funnel heat into the Sun's outer atmosphere.
The acoustic waves can be extremely energetic, reaching heights of tens of miles, and can travel at rapid speeds of 45,000 to 90,000 miles per hour. "These [explosions] release energy equivalent to millions of hydrogen bombs," von Fay-Siebenburgen said.
"These energies are plucking these magnetic strings or standing pipes, which set up standing waves--exactly the same waves you see on a guitar string," von Fay-Siebenburgen told SPACE.com. The "sound booms" decay to silence in less than an hour, dissipating in the hot solar corona.
Solar physics
The musical finding could help explain why the Sun's corona is so hot.
While the Sun's surface is a steamy 10,000 degrees Fahrenheit (5,538 degrees Celsius), plasma gas in the corona soars to more than 100 times hotter.
"How can the atmosphere above the surface of the Sun be hotter if nuclear fusion happens inside the Sun?" von Fay-Siebenburgen said. If astronomers can get a clearer picture of what's going on inside these magnetic loops in the Sun's atmosphere, they have a better chance of finding the answer.
Another recent study using images from Hinode's telescope revealed twisted magnetic fields along the Sun's surface, which store huge amounts of energy. The magnetic fields can snap like a rubber band; when they do, they might release energy that could heat up the corona or power solar eruptions and coronal mass ejections, the researchers say.
Video: Sun Storms
Images: Solar Flares
Twisted Solution to Sun's Mystery Heat
Original Story: Sun's Atmosphere Sings
Visit SPACE.com and explore our huge collection of Space Pictures, Space Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting and Amazing Images. Follow the latest developments in the search for life in our universe in our SETI: Search for Life section. Join the community, sign up for our free daily email newsletter, listen to our Podcasts, check out our RSS feeds and other Reader Favorites today!
Jeanna BrynerStaff WriterSPACE.com
Snagging orchestra seats for this solar symphony would be fruitless, however, as the frequency of the sound waves is below the human hearing threshold. While humans can make out sounds between 20 and 20,000 hertz, the solar sound waves are on the order of milli-hertz--a thousandth of a hertz.
The study, presented this week at the Royal Astronomical Society's National Astronomy Meeting in Lancashire, England, reveals that the looping magnetic fields along the Sun's outer regions, called the corona, carry magnetic sound waves in a similar manner to musical instruments such as guitars or pipe organs.
Making music
Robertus von Fay-Siebenburgen of the Solar Physics and Space Plasma Research Center at the University of Sheffield and his colleagues combined information gleaned from sun-orbiting satellites with theoretical models of solar processes, such as coronal mass ejections.
They found that explosive events at the Sun's surface appear to trigger acoustic waves that bounce back and forth between both ends of the loops, a phenomenon known as a standing wave.
"These magnetic loops are analogous to a simple guitar string," von Fay-Siebenburgen explained. "If you pluck a guitar string, you will hear the music."
In the cosmic equivalent of a guitar pick, so-called microflares at the base of loops could be plucking the magnetic loops and setting the sound waves in motion, the researchers speculate. While solar flares are the largest explosions in the solar system, microflares are a million times smaller but much more frequent; both phenomena are now thought to funnel heat into the Sun's outer atmosphere.
The acoustic waves can be extremely energetic, reaching heights of tens of miles, and can travel at rapid speeds of 45,000 to 90,000 miles per hour. "These [explosions] release energy equivalent to millions of hydrogen bombs," von Fay-Siebenburgen said.
"These energies are plucking these magnetic strings or standing pipes, which set up standing waves--exactly the same waves you see on a guitar string," von Fay-Siebenburgen told SPACE.com. The "sound booms" decay to silence in less than an hour, dissipating in the hot solar corona.
Solar physics
The musical finding could help explain why the Sun's corona is so hot.
While the Sun's surface is a steamy 10,000 degrees Fahrenheit (5,538 degrees Celsius), plasma gas in the corona soars to more than 100 times hotter.
"How can the atmosphere above the surface of the Sun be hotter if nuclear fusion happens inside the Sun?" von Fay-Siebenburgen said. If astronomers can get a clearer picture of what's going on inside these magnetic loops in the Sun's atmosphere, they have a better chance of finding the answer.
Another recent study using images from Hinode's telescope revealed twisted magnetic fields along the Sun's surface, which store huge amounts of energy. The magnetic fields can snap like a rubber band; when they do, they might release energy that could heat up the corona or power solar eruptions and coronal mass ejections, the researchers say.
Video: Sun Storms
Images: Solar Flares
Twisted Solution to Sun's Mystery Heat
Original Story: Sun's Atmosphere Sings
Visit SPACE.com and explore our huge collection of Space Pictures, Space Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting and Amazing Images. Follow the latest developments in the search for life in our universe in our SETI: Search for Life section. Join the community, sign up for our free daily email newsletter, listen to our Podcasts, check out our RSS feeds and other Reader Favorites today!
Jeanna BrynerStaff WriterSPACE.com
Friday, April 06, 2007
Mystery of Greek Amphitheater's Amazing Sound Finally Solved
Cut the chatter! The ancient mystery surrounding the great acoustics of the theater at Epidaurus in Greece has been solved.
The theater, dating to the 4th century B.C. and arranged in 55 semi-circular rows, remains the great masterwork of Polykleitos the Younger. Audiences of up to an estimated 14,000 have long been able to hear actors and musicians—unamplified—from even the back row of the architectural masterpiece.
How this sonic quality was achieved has been the source of academic and amateur speculation, with some theories suggesting that prevailing winds carried sounds or masks amplified voices.
It's in the seats
Now, researchers at the Georgia Institute of Technology have discovered that the limestone material of the seats provide a filtering effect, suppressing low frequencies of voices, thus minimizing background crowd noise. Further, the rows of limestone seats reflect high-frequencies back towards the audience, enhancing the effect.
Researcher Nico Declercq, a mechanical engineer, initially suspected that the slope of the theater had something to do with the effect.
“When I first tackled this problem, I thought that the effect of the splendid acoustics was due to surface waves climbing the theater with almost no damping,” Declercq said. “While the voices of the performers were being carried, I didn’t anticipate that the low frequencies of speech were also filtered out to some extent.”
However, experiments with ultrasonic waves and numerical models indicated that frequencies up to 500 hertz (cycles per second) were lowered, and frequencies higher than 500 hertz went undiminished, he said.
Acoustic traps
The corrugations on the surface of the seats act as natural acoustic traps. Though this effect would seem to also remove the low frequencies from the actors' voices, listeners actually fill in the missing portion of the audio spectrum through a phenomenon known as virtual pitch. The human brain reconstructs the missing frequencies, producing the virtual pitch phenomenon, as in listening to someone speaking on a telephone with no low end.
The findings are detailed in the April issue of the Journal of the Acoustics Society of America.
Amazingly, the Greek builders of the theater did not themselves understand the principles that led to the exceptional audibility of sound from the stage.
Attempts to recreate the Epidaurus design never quite matched the original. Later seating arrangements featured other materials, such as wood for the benches, an approach which may have ultimately derailed the design duplication effort.
Music Tickles Strong Memories
Singing Sand Dunes: The Mystery of Desert Music
Top 10 Ancient Capitals
Original Story: Mystery of Greek Amphitheater's Amazing Sound Finally Solved
Tom ChaoLiveScience Staff WriterLiveScience.com
The theater, dating to the 4th century B.C. and arranged in 55 semi-circular rows, remains the great masterwork of Polykleitos the Younger. Audiences of up to an estimated 14,000 have long been able to hear actors and musicians—unamplified—from even the back row of the architectural masterpiece.
How this sonic quality was achieved has been the source of academic and amateur speculation, with some theories suggesting that prevailing winds carried sounds or masks amplified voices.
It's in the seats
Now, researchers at the Georgia Institute of Technology have discovered that the limestone material of the seats provide a filtering effect, suppressing low frequencies of voices, thus minimizing background crowd noise. Further, the rows of limestone seats reflect high-frequencies back towards the audience, enhancing the effect.
Researcher Nico Declercq, a mechanical engineer, initially suspected that the slope of the theater had something to do with the effect.
“When I first tackled this problem, I thought that the effect of the splendid acoustics was due to surface waves climbing the theater with almost no damping,” Declercq said. “While the voices of the performers were being carried, I didn’t anticipate that the low frequencies of speech were also filtered out to some extent.”
However, experiments with ultrasonic waves and numerical models indicated that frequencies up to 500 hertz (cycles per second) were lowered, and frequencies higher than 500 hertz went undiminished, he said.
Acoustic traps
The corrugations on the surface of the seats act as natural acoustic traps. Though this effect would seem to also remove the low frequencies from the actors' voices, listeners actually fill in the missing portion of the audio spectrum through a phenomenon known as virtual pitch. The human brain reconstructs the missing frequencies, producing the virtual pitch phenomenon, as in listening to someone speaking on a telephone with no low end.
The findings are detailed in the April issue of the Journal of the Acoustics Society of America.
Amazingly, the Greek builders of the theater did not themselves understand the principles that led to the exceptional audibility of sound from the stage.
Attempts to recreate the Epidaurus design never quite matched the original. Later seating arrangements featured other materials, such as wood for the benches, an approach which may have ultimately derailed the design duplication effort.
Music Tickles Strong Memories
Singing Sand Dunes: The Mystery of Desert Music
Top 10 Ancient Capitals
Original Story: Mystery of Greek Amphitheater's Amazing Sound Finally Solved
Tom ChaoLiveScience Staff WriterLiveScience.com
Friday, March 23, 2007
France opens secret UFO files covering 50 years
PARIS (AFP) - France became the first country to open its files on UFOs Thursday when the national space agency unveiled a website documenting more than 1,600 sightings spanning five decades.
The online archives, which will be updated as new cases are reported, catalogues in minute detail cases ranging from the easily dismissed to a handful that continue to perplex even hard-nosed scientists.
"It is a world first," said Jacques Patenet, the aeronautical engineer who heads the office for the study of "non-identified aerospatial phenomena."
Known as OVNIs in French, UFOs have always generated intense interest along with countless conspiracy theories about secretive government cover-ups of findings deemed too sensitive or alarming for public consumption.
"Cases such as the lady who reported seeing an object that looked like a flying roll of toilet paper" are clearly not worth investigating, said Patenet.
But many others involving multiple sightings -- in at least one case involving thousands of people across France -- and evidence such as burn marks and radar trackings showing flight patterns or accelerations that defy the laws of physics are taken very seriously.
A phalanx of beefy security guards formed a barrier in front of the space agency (CNES) headquarters where the announcement was made, "to screen out uninvited UFOlogists," an official explained.
Of the 1,600 cases registered since 1954, nearly 25 percent are classified as "type D", meaning that "despite good or very good data and credible witnesses, we are confronted with something we can't explain," Patenet said.
On January 8, 1981 outside the town of Trans-en-Provence in southern France, for example, a man working in a field reported hearing a strange whistling sound and seeing a saucer-like object about 2.5 meters (eight feet) in diameter land in his field about 50 meters (yards) away.
A dull-zinc grey, the saucer took off, he told police, almost immediately, leaving burn marks.
Investigators took photos, and then collected and analyzed samples, and to this day no satisfactory explanation has been made.
The nearly 1,000 witness who said they saw flashing lights in the sky on November 5, 1990, by contrast, had simply seen a rocket fragment falling back into earth's atmosphere.
Patenet's answer to questions about evidence of life beyond Earth was sure to inflame the suspicions of those convinced the government is holding back: "We do not have the least proof that extra-terrestrials are behind the unexplained phenomena."
But then he added: "Nor do we have the least proof that they aren't."
The CNES fields between 50 and 100 UFO reports ever year, usually written up by police. Of these, 10 percent are the object of on-site investigations, Patenet said.
Other countries collect data more or less systematically about unidentified flying objects, notably in Britain and in the United States, where information can be requested on a case-by-case basis under the Freedom of Information Act.
"But we decided to do it the other way around and made everything available to the public," Patenet said.
The aim was to make it easier for scientists and other UFO buffs to access the data for research.
The website itself -- which crashed host servers hours after it was unveiled due to heavy traffic -- is extremely well organized and complete, even including scanned copies of police reports.
To visit the website: www.cnes-geipan.fr.
by Marlowe Hood
The online archives, which will be updated as new cases are reported, catalogues in minute detail cases ranging from the easily dismissed to a handful that continue to perplex even hard-nosed scientists.
"It is a world first," said Jacques Patenet, the aeronautical engineer who heads the office for the study of "non-identified aerospatial phenomena."
Known as OVNIs in French, UFOs have always generated intense interest along with countless conspiracy theories about secretive government cover-ups of findings deemed too sensitive or alarming for public consumption.
"Cases such as the lady who reported seeing an object that looked like a flying roll of toilet paper" are clearly not worth investigating, said Patenet.
But many others involving multiple sightings -- in at least one case involving thousands of people across France -- and evidence such as burn marks and radar trackings showing flight patterns or accelerations that defy the laws of physics are taken very seriously.
A phalanx of beefy security guards formed a barrier in front of the space agency (CNES) headquarters where the announcement was made, "to screen out uninvited UFOlogists," an official explained.
Of the 1,600 cases registered since 1954, nearly 25 percent are classified as "type D", meaning that "despite good or very good data and credible witnesses, we are confronted with something we can't explain," Patenet said.
On January 8, 1981 outside the town of Trans-en-Provence in southern France, for example, a man working in a field reported hearing a strange whistling sound and seeing a saucer-like object about 2.5 meters (eight feet) in diameter land in his field about 50 meters (yards) away.
A dull-zinc grey, the saucer took off, he told police, almost immediately, leaving burn marks.
Investigators took photos, and then collected and analyzed samples, and to this day no satisfactory explanation has been made.
The nearly 1,000 witness who said they saw flashing lights in the sky on November 5, 1990, by contrast, had simply seen a rocket fragment falling back into earth's atmosphere.
Patenet's answer to questions about evidence of life beyond Earth was sure to inflame the suspicions of those convinced the government is holding back: "We do not have the least proof that extra-terrestrials are behind the unexplained phenomena."
But then he added: "Nor do we have the least proof that they aren't."
The CNES fields between 50 and 100 UFO reports ever year, usually written up by police. Of these, 10 percent are the object of on-site investigations, Patenet said.
Other countries collect data more or less systematically about unidentified flying objects, notably in Britain and in the United States, where information can be requested on a case-by-case basis under the Freedom of Information Act.
"But we decided to do it the other way around and made everything available to the public," Patenet said.
The aim was to make it easier for scientists and other UFO buffs to access the data for research.
The website itself -- which crashed host servers hours after it was unveiled due to heavy traffic -- is extremely well organized and complete, even including scanned copies of police reports.
To visit the website: www.cnes-geipan.fr.
by Marlowe Hood
Tuesday, March 20, 2007
Mathematicians solve E8 structure
WASHINGTON (AFP) - After four years of intensive collaboration, 18 top mathematicians and computer scientists from the United States and Europe have successfully mapped E8, one of the largest and most complicated structures in mathematics, scientists said late Sunday.
Jeffrey Adams, project leader and mathematics professor at the University of Maryland said E8 was discovered over a century ago, in 1887, and until now, no one thought the structure could ever be understood.
"This groundbreaking achievement is significant both as an advance in basic knowledge, as well as a major advance in the use of large scale computing to solve complicated mathematical problems," Adams said.
He added that the mapping of E8 may well have unforeseen implications in mathematics and physics which won't be evident for years to come.
E8 belongs to so-called Lie groups that were invented by a 19th century Norwegian mathematician, Sophus Lie, to study symmetry.
The theory holds that underlying any symmetrical object, such as a sphere, is a Lie group.
Balls, cylinders or cones are familiar examples of symmetric three-dimensional objects.
However, mathematicians study symmetries in higher dimensions. In fact, E8 itself is 248-dimensional.
Today string theorists search for a theory of the universe by looking at E8 X E8.
The scientists said the magnitude of the E8 calculation invited comparison with the
Human Genome Project.
While the human genome, which contains all the genetic information of a cell, is less than a gigabyte in size, the result of the E8 calculation, which contains all the information about E8, is 60 gigabytes in size, they said.
This is enough to store 45 days of continuous music in MP3-format. If written out on paper, the answer would cover an area the size of Manhattan.
Jeffrey Adams, project leader and mathematics professor at the University of Maryland said E8 was discovered over a century ago, in 1887, and until now, no one thought the structure could ever be understood.
"This groundbreaking achievement is significant both as an advance in basic knowledge, as well as a major advance in the use of large scale computing to solve complicated mathematical problems," Adams said.
He added that the mapping of E8 may well have unforeseen implications in mathematics and physics which won't be evident for years to come.
E8 belongs to so-called Lie groups that were invented by a 19th century Norwegian mathematician, Sophus Lie, to study symmetry.
The theory holds that underlying any symmetrical object, such as a sphere, is a Lie group.
Balls, cylinders or cones are familiar examples of symmetric three-dimensional objects.
However, mathematicians study symmetries in higher dimensions. In fact, E8 itself is 248-dimensional.
Today string theorists search for a theory of the universe by looking at E8 X E8.
The scientists said the magnitude of the E8 calculation invited comparison with the
Human Genome Project.
While the human genome, which contains all the genetic information of a cell, is less than a gigabyte in size, the result of the E8 calculation, which contains all the information about E8, is 60 gigabytes in size, they said.
This is enough to store 45 days of continuous music in MP3-format. If written out on paper, the answer would cover an area the size of Manhattan.
Sunday, March 18, 2007
Giant Pool of Water Ice at Mars' South Pole
Mars is unlikely to sport beachfront property anytime soon, but the planet has enough water ice at its south pole to blanket the entire planet in more than 30 feet of water if everything thawed out.
With a radar technique, astronomers have penetrated for the first time about 2.5 miles (nearly four kilometers) beneath the south pole's frozen surface. The data showed that nearly pure water ice lies beneath.
Discovered in the early 1970s, layered deposits of ice and dust cap the North and South Poles of Mars. Until now, the deposits have been difficult to study closely with existing telescopes and satellites. The current advance comes from a probe of the deposits using an instrument aboard the Mars Express orbiter.
"This is the first time that a ground-penetrating system has ever been used on Mars," said the new radar study's lead author, Jeffrey Plaut of NASA's Jet Propulsion Laboratory. "All the other instruments used to study the surface of Mars in the past really have only been sensitive to what occurs at the very surface."
(NASA's Mars Odyssey spacecraft also carries instruments designed, among other things, to probe beneath icy polar surfaces.)
Deep probe
Plaut and his colleagues probed the deposits with radar echo sounding, typically used on Earth to study the interiors of glaciers. The instrument, called the Mars Advanced Radar for Subsurface and Ionospheric Sounding, or MARSIS, beams radio waves which penetrate the planet's surface and bounce off features having different electrical properties.
The reflected beams revealed that 90 percent or more of the frozen polar material is pure water ice, sprinkled with dust particles. The scientists calculated that the water would form a 36-foot-deep ocean of sorts if spread over the Martian globe.
"It's the best evidence that's been obtained to date for that thickness," said Ken Herkenhoff, a planetary geologist at the U.S. Geological Survey in Flagstaff, Ariz., who studies the Martian polar regions. He was not involved in the current study.
Scientists have long known that Mars' north polar cap is a massive storehouse of water ice, and the current research team says they will use their radar technique to refine past estimates of its thickness and make-up.
Missing water
"These polar ice deposits are by far the largest reservoir of water or water ice that we know of on Mars," Plaut said.
That's a lot of water, but not enough to account for the flowing streams thought to meander along Mars' surface in the past.
"There's evidence that about 10 times or maybe even 100 times that much water has flowed across the surface of Mars to carve the various channels, the outflow valleys and other features we see in the images and topography data," Plaut told SPACE.com.
So where's the rest of the water? One idea is that a subterranean plumbing system once ferried loads of water beneath the Martian surface. Plaut said his team also will search for underground pools with the radar technique.
Underground Plumbing System Discovered on Mars
New View of Ancient Mars Water System
Martian beach
A Martian water-world is unlikely in the near future, but astronomers have solid evidence that billions of years ago water flowed over the Martian surface. And recently, evidence has pointed to a warming trend as Mars emerges from an "ice age."
Scientists think variations in Mars' orbit and tilt drive the planet's climate over time, though a few astronomers have speculated about how the Sun's activity could be partly to blame for warming on several planets.
Sun Blamed for Warming of Earth and Other Worlds
In addition to warming from the atmosphere, ice-thawing heat could come from the core of Mars, analogous to the plumes of heat that cause volcanic eruptions on Earth. But evidence from the new radar study suggests the Martian crust is icy cold and rigid.
Mars Madness: A Multimedia Adventure
Top 10 Best Mars Images Ever
Video: A Wet Modern Mars?
Images: Ice on Mars
All About Mars
Original Story: Giant Pool of Water Ice at Mars' South Pole
Visit SPACE.com and explore our huge collection of Space Pictures, Space Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting and Amazing Images. Follow the latest developments in the search for life in our universe in our SETI: Search for Life section. Join the community, sign up for our free daily email newsletter, listen to our Podcasts, check out our RSS feeds and other Reader Favorites today!
Jeanna BrynerStaff WriterSPACE.com
With a radar technique, astronomers have penetrated for the first time about 2.5 miles (nearly four kilometers) beneath the south pole's frozen surface. The data showed that nearly pure water ice lies beneath.
Discovered in the early 1970s, layered deposits of ice and dust cap the North and South Poles of Mars. Until now, the deposits have been difficult to study closely with existing telescopes and satellites. The current advance comes from a probe of the deposits using an instrument aboard the Mars Express orbiter.
"This is the first time that a ground-penetrating system has ever been used on Mars," said the new radar study's lead author, Jeffrey Plaut of NASA's Jet Propulsion Laboratory. "All the other instruments used to study the surface of Mars in the past really have only been sensitive to what occurs at the very surface."
(NASA's Mars Odyssey spacecraft also carries instruments designed, among other things, to probe beneath icy polar surfaces.)
Deep probe
Plaut and his colleagues probed the deposits with radar echo sounding, typically used on Earth to study the interiors of glaciers. The instrument, called the Mars Advanced Radar for Subsurface and Ionospheric Sounding, or MARSIS, beams radio waves which penetrate the planet's surface and bounce off features having different electrical properties.
The reflected beams revealed that 90 percent or more of the frozen polar material is pure water ice, sprinkled with dust particles. The scientists calculated that the water would form a 36-foot-deep ocean of sorts if spread over the Martian globe.
"It's the best evidence that's been obtained to date for that thickness," said Ken Herkenhoff, a planetary geologist at the U.S. Geological Survey in Flagstaff, Ariz., who studies the Martian polar regions. He was not involved in the current study.
Scientists have long known that Mars' north polar cap is a massive storehouse of water ice, and the current research team says they will use their radar technique to refine past estimates of its thickness and make-up.
Missing water
"These polar ice deposits are by far the largest reservoir of water or water ice that we know of on Mars," Plaut said.
That's a lot of water, but not enough to account for the flowing streams thought to meander along Mars' surface in the past.
"There's evidence that about 10 times or maybe even 100 times that much water has flowed across the surface of Mars to carve the various channels, the outflow valleys and other features we see in the images and topography data," Plaut told SPACE.com.
So where's the rest of the water? One idea is that a subterranean plumbing system once ferried loads of water beneath the Martian surface. Plaut said his team also will search for underground pools with the radar technique.
Underground Plumbing System Discovered on Mars
New View of Ancient Mars Water System
Martian beach
A Martian water-world is unlikely in the near future, but astronomers have solid evidence that billions of years ago water flowed over the Martian surface. And recently, evidence has pointed to a warming trend as Mars emerges from an "ice age."
Scientists think variations in Mars' orbit and tilt drive the planet's climate over time, though a few astronomers have speculated about how the Sun's activity could be partly to blame for warming on several planets.
Sun Blamed for Warming of Earth and Other Worlds
In addition to warming from the atmosphere, ice-thawing heat could come from the core of Mars, analogous to the plumes of heat that cause volcanic eruptions on Earth. But evidence from the new radar study suggests the Martian crust is icy cold and rigid.
Mars Madness: A Multimedia Adventure
Top 10 Best Mars Images Ever
Video: A Wet Modern Mars?
Images: Ice on Mars
All About Mars
Original Story: Giant Pool of Water Ice at Mars' South Pole
Visit SPACE.com and explore our huge collection of Space Pictures, Space Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting and Amazing Images. Follow the latest developments in the search for life in our universe in our SETI: Search for Life section. Join the community, sign up for our free daily email newsletter, listen to our Podcasts, check out our RSS feeds and other Reader Favorites today!
Jeanna BrynerStaff WriterSPACE.com
EU site to offer extreme weather data
VIENNA, Austria - It looks like a color-coded terror alert scale — and meteorologically speaking, that's exactly what it is. With climate change making conditions more unpredictable, national weather services from across the European Union have joined forces to create http://www.meteoalarm.eu — a new Web site providing up-to-the-minute information on "extreme weather" across the continent.
The initiative, managed by Austria's Central Institute for Meteorology and Geodynamics, is designed to give Europeans a single source for details on flash floods, severe thunderstorms, gale-force winds, heat waves, blizzards and other violent weather that poses a threat to life or property.
It also issues 24- and 48-hour warnings for heavy fog, extreme cold, forest fires and "coastal events" such as high waves or severe tides.
"In one glance you will be able to see where in Europe the weather might become dangerous," organizers said Saturday in a statement.
The service is similar to the United States' National Weather Service, which posts on its Web site conditions, warnings and forecasts for all 50 states.
Although the European site officially will launch in Madrid, Spain, on March 23 — World Meteorological Day — it is already live on the Web in test form.
Under the new pan-European warning system, white means missing or insufficient data; green means no imminent threat; yellow signifies potentially dangerous weather; orange warns of dangerous conditions; and red means very dangerous, "exceptionally intense" weather.
Pictograms and photographs showing lightning bolts, churning floodwaters and other catastrophic scenes also pop up "to make the general public more conscious or aware" of a particular threat, the organizers said.
Users click on maps to get details on current conditions or forecasts of violent weather for the next day. There are also links to a country's national weather service.
The Network of European Meteorological Services includes 20 countries and covers land stretching from Portugal to Sweden. Not every nation in the region is contributing, but the site hopes to bring others online eventually.
The Web site "pulls together all the warnings from the official national weather services," said Michael Staudinger of the Vienna weather institute.
It seemed to be accurate on Saturday, at least for Vienna, which was buffeted by gale-force winds gusting to 50 mph. The system churned out a yellow high-wind warning for the area and provided details in German and English.
By WILLIAM J. KOLE, Associated Press Writer
The initiative, managed by Austria's Central Institute for Meteorology and Geodynamics, is designed to give Europeans a single source for details on flash floods, severe thunderstorms, gale-force winds, heat waves, blizzards and other violent weather that poses a threat to life or property.
It also issues 24- and 48-hour warnings for heavy fog, extreme cold, forest fires and "coastal events" such as high waves or severe tides.
"In one glance you will be able to see where in Europe the weather might become dangerous," organizers said Saturday in a statement.
The service is similar to the United States' National Weather Service, which posts on its Web site conditions, warnings and forecasts for all 50 states.
Although the European site officially will launch in Madrid, Spain, on March 23 — World Meteorological Day — it is already live on the Web in test form.
Under the new pan-European warning system, white means missing or insufficient data; green means no imminent threat; yellow signifies potentially dangerous weather; orange warns of dangerous conditions; and red means very dangerous, "exceptionally intense" weather.
Pictograms and photographs showing lightning bolts, churning floodwaters and other catastrophic scenes also pop up "to make the general public more conscious or aware" of a particular threat, the organizers said.
Users click on maps to get details on current conditions or forecasts of violent weather for the next day. There are also links to a country's national weather service.
The Network of European Meteorological Services includes 20 countries and covers land stretching from Portugal to Sweden. Not every nation in the region is contributing, but the site hopes to bring others online eventually.
The Web site "pulls together all the warnings from the official national weather services," said Michael Staudinger of the Vienna weather institute.
It seemed to be accurate on Saturday, at least for Vienna, which was buffeted by gale-force winds gusting to 50 mph. The system churned out a yellow high-wind warning for the area and provided details in German and English.
By WILLIAM J. KOLE, Associated Press Writer
Wednesday, March 07, 2007
Scientists study Earth's missing crust
SANTA CRUZ DE TENERIFE, Canary Islands - British scientists have embarked on a mission to study a huge area on the Atlantic seabed where the Earth's crust is mysteriously missing and instead is covered with dark green rock from deep inside the planet.
The 12-member expedition to take an unprecedented peek at Earth's mantle left the Canary Islands on Monday with a new high-tech vessel and a robotic device named Toby that will dig up rock samples at the site and film what it sees.
The main site — there is at least one other in roughly the same area and a third is suspected — is about three miles below the surface of the Atlantic and located about 2,000 nautical miles southwest of the Canaries.
It is part of a globe-spanning ridge of undersea volcanos, the kind of structure that forms when Atlantic tectonic plates separate and lava surges upward to fill the gap in the Earth's crust.
But that apparently did not happen this time. Where there should be a four-mile-thick layer of crust, there is instead that much mantle — the very dense, dark green rock that makes up the deep inner layer of the Earth.
Scientists have seen chunks of mantle that have been spewed up with lava, but never such a large, exposed stretch.
"It is like a window into the interior of the Earth," Bramley Murton, a geophysicist who is taking part in the six-week mission, said Tuesday from the research ship RRS James Cook as it headed to the site, still five days away.
This exposed layer is irregularly shaped, about 30 miles long and perhaps that distance or more at its widest. It was detected about five years ago with sonar from a surface vessel.
There are two main theories as to what happened, Murton said: A fault ripped away huge chunks of crust, or in an area of crust-forming volcanoes, this area was mysteriously devoid of that outer material, Murton said.
Roger Searle of Durham University, one of the lead researchers, said the study aims to provide insight on everything from the chemistry of oceans to the mechanisms of how the Earth behaves under so much water.
The robotic device will land on the exposed mantle, deploy a drill, and dig into the rock to bring back samples.
The project is being financed by Britain's National Environment Research Council and the Department of trade and Industry's Large Scientific Facilities Fund.
By JUAN MANUEL PARDELLAS, Associated Press Writer
The 12-member expedition to take an unprecedented peek at Earth's mantle left the Canary Islands on Monday with a new high-tech vessel and a robotic device named Toby that will dig up rock samples at the site and film what it sees.
The main site — there is at least one other in roughly the same area and a third is suspected — is about three miles below the surface of the Atlantic and located about 2,000 nautical miles southwest of the Canaries.
It is part of a globe-spanning ridge of undersea volcanos, the kind of structure that forms when Atlantic tectonic plates separate and lava surges upward to fill the gap in the Earth's crust.
But that apparently did not happen this time. Where there should be a four-mile-thick layer of crust, there is instead that much mantle — the very dense, dark green rock that makes up the deep inner layer of the Earth.
Scientists have seen chunks of mantle that have been spewed up with lava, but never such a large, exposed stretch.
"It is like a window into the interior of the Earth," Bramley Murton, a geophysicist who is taking part in the six-week mission, said Tuesday from the research ship RRS James Cook as it headed to the site, still five days away.
This exposed layer is irregularly shaped, about 30 miles long and perhaps that distance or more at its widest. It was detected about five years ago with sonar from a surface vessel.
There are two main theories as to what happened, Murton said: A fault ripped away huge chunks of crust, or in an area of crust-forming volcanoes, this area was mysteriously devoid of that outer material, Murton said.
Roger Searle of Durham University, one of the lead researchers, said the study aims to provide insight on everything from the chemistry of oceans to the mechanisms of how the Earth behaves under so much water.
The robotic device will land on the exposed mantle, deploy a drill, and dig into the rock to bring back samples.
The project is being financed by Britain's National Environment Research Council and the Department of trade and Industry's Large Scientific Facilities Fund.
By JUAN MANUEL PARDELLAS, Associated Press Writer
Sunday, March 04, 2007
World watches 1st total lunar eclipse in 3 years
LONDON - The moon darkened, reddened, and turned shades of gray and orange Saturday night during the first total lunar eclipse in nearly three years, thrilling stargazers and astronomers around the world.
The Earth’s shadow took over six hours to crawl across the moon’s surface, eating it into a crescent shape before engulfing it completely in a spectacle at least partly visible on every continent.
About a dozen amateur astronomers braved the cold and mud outside the Croydon Observatory in southeast London to watch the start of the eclipse.
“It’s starting to go!” said Alex Gikas, 8, a Cub Scout who was studying for his astronomy badge. “I’ve never seen anything like it before. I’m really excited.”
By the time greatest eclipse, shortly after 5:44 p.m. EST, the light of the full moon was replaced by near-total obscurity.
“It was really very dark,” said Paul Harper, Chairman of the Croydon Astronomical Society, who estimated that moon had lost over four-fifths of its luminosity. “It was quite a nice one.”
Lunar eclipses occur when Earth passes between the sun and the moon, an uncommon event because the moon spends most of its time either above or below the plane of Earth’s orbit.
Sunlight still reaches the moon during total eclipses, but it is refracted through Earth’s atmosphere, bathing the moon in an eerie crimson light.
Mike Ealay, a 60-year-old architect who wandered over to the observatory to watch the eclipse, said the red color of the moon made it look like a close-up version of Mars.
“I think it’s quite exciting. It’s like having the red planet on your doorstep,” he said.
Despite cloudy conditions over much of Europe, a variety of Webcasts carried the event live, and astronomers urged the public not to miss out on the spectacle.
“It’s not an event that has any scientific value, but it’s something everybody can enjoy,” said Robert Massey, of Britain’s Royal Astronomical Society.
The moon’s red blush faded as it began moving out of Earth’s shadow just after 8 p.m. EST. The eclipse ended a little more than hour later.
Residents of east Asia saw the eclipse cut short by moonset, while those in the eastern parts of North and South America had the moon already partially or totally eclipsed by the time it rose over the horizon in the evening.
While eastern Australia, Alaska and New Zealand missed Saturday’s show, they will have front row seats to the next total lunar eclipse, on Aug. 28.
© 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
The Earth’s shadow took over six hours to crawl across the moon’s surface, eating it into a crescent shape before engulfing it completely in a spectacle at least partly visible on every continent.
About a dozen amateur astronomers braved the cold and mud outside the Croydon Observatory in southeast London to watch the start of the eclipse.
“It’s starting to go!” said Alex Gikas, 8, a Cub Scout who was studying for his astronomy badge. “I’ve never seen anything like it before. I’m really excited.”
By the time greatest eclipse, shortly after 5:44 p.m. EST, the light of the full moon was replaced by near-total obscurity.
“It was really very dark,” said Paul Harper, Chairman of the Croydon Astronomical Society, who estimated that moon had lost over four-fifths of its luminosity. “It was quite a nice one.”
Lunar eclipses occur when Earth passes between the sun and the moon, an uncommon event because the moon spends most of its time either above or below the plane of Earth’s orbit.
Sunlight still reaches the moon during total eclipses, but it is refracted through Earth’s atmosphere, bathing the moon in an eerie crimson light.
Mike Ealay, a 60-year-old architect who wandered over to the observatory to watch the eclipse, said the red color of the moon made it look like a close-up version of Mars.
“I think it’s quite exciting. It’s like having the red planet on your doorstep,” he said.
Despite cloudy conditions over much of Europe, a variety of Webcasts carried the event live, and astronomers urged the public not to miss out on the spectacle.
“It’s not an event that has any scientific value, but it’s something everybody can enjoy,” said Robert Massey, of Britain’s Royal Astronomical Society.
The moon’s red blush faded as it began moving out of Earth’s shadow just after 8 p.m. EST. The eclipse ended a little more than hour later.
Residents of east Asia saw the eclipse cut short by moonset, while those in the eastern parts of North and South America had the moon already partially or totally eclipsed by the time it rose over the horizon in the evening.
While eastern Australia, Alaska and New Zealand missed Saturday’s show, they will have front row seats to the next total lunar eclipse, on Aug. 28.
© 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Monday, February 26, 2007
Population Density of Madagascar
Source: UNOSAT
Reuters and AlertNet are not responsible for the content of this article or for any external internet sites. The views expressed are the author's alone.
Reuters and AlertNet are not responsible for the content of this article or for any external internet sites. The views expressed are the author's alone.
Tropical Cyclone Gamede Track As of 26 February 2007 This map illustrates the approximate population density (2004) for Madagascar, which is currently threatened by tropical cyclone Gamede. Map Scale 1:4,200,000 for A3 Print Projection: Lambert Conformal Conic Datum: WGS-84 Population Data: Landscan 2004 Storm Data: GDACS, WMO GIS Data: SALB, NGA, UNEP, GEBCO Map Production: UNOSAT (26 February 2007)
Madagascar - Tropical Cyclone Gamede Track As of 26 February 2007
This map illustrates the approximate population density (2004) for Madagascar, which is currently threatened by tropical cyclone Gamede. Map Scale 1:4,200,000 for A3 Print Projection: Lambert Conformal Conic Datum: WGS-84
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