WASHINGTON – It's not just families that are getting together this Thanksgiving week. The three brightest objects in the night sky — Venus, Jupiter and a crescent moon — will crowd around each other for an unusual group shot.
Starting Thanksgiving evening, Jupiter and Venus will begin moving closer so that by Sunday and Monday, they will appear 2 degrees apart, which is about a finger width held out at arm's length, said Alan MacRobert, senior editor at Sky and Telescope magazine. Then on Monday night, they will be joined by a crescent moon right next to them, he said.
Look in the southwestern sky around twilight — no telescope or binoculars needed. The show will even be visible in cities if it's a clear night.
"It'll be a head-turner," MacRobert said. "This certainly is an unusual coincidence for the crescent moon to be right there in the days when they are going to be closest together."
The moon is the brightest, closest and smallest of the three and is 252,000 miles away. Venus, the second brightest, closest and smallest, is 94 million miles away. And big Jupiter is 540 million miles away.
The three celestial objects come together from time to time, but often they are too close to the sun or unite at a time when they aren't so visible. The next time the three will be as close and visible as this week will be Nov. 18, 2052, according to Jack Horkheimer, director of the Miami Space Transit Planetarium.
But if you are willing to settle for two out of three — Venus and the crescent moon only — it will happen again on New Year's Eve, MacRobert said.
By SETH BORENSTEIN, AP Science Writer Seth Borenstein, Ap Science Writer – Tue Nov 25, 4:21 pm ET
Thursday, November 27, 2008
Tuesday, November 25, 2008
Cave bears killed by Ice Age, not hunters: study
OSLO (Reuters) - Giant cave bears froze to death during the last Ice Age in Europe about 28,000 years ago, according to a study on Wednesday that cleared human hunters of driving them to extinction thousands of years later.
The largely vegetarian bears, weighing up to a tonne and bigger than modern polar bears or Kodiak bears, apparently died off as a sharp cooling of the climate led to a freeze that killed off the fruits, nuts and plants they ate.
The bears vanished 27,800 years ago, or about 13,000 years earlier than previously believed, the scientists in Austria and Britain said in a study of bear remains using radiocarbon dating including at hibernation sites in the Alps.
"There is little convincing evidence so far of human involvement in extinction of the cave bear," they wrote in the journal Boreas. Some past reports have suggested that the cave bears' demise was linked to over-hunting.
Cave bears ranged from what is now Spain to the Ural Mountains, and were one of several large creatures -- such as the woolly mammoth, woolly rhinoceros, giant deer and cave lion -- to vanish during the Ice Age that ended 10,000 years ago.
"Our work shows that the cave bear ... was one of the earliest to disappear," Martina Pacher, one of the co-authors at the University of Vienna, said in a statement.
"Other, later extinctions happened at different times within the last 15,000 years," she said. Previous studies had errors in dating samples and sometimes confused remains of cave bears with those of brown bears, which still survive.
"A fundamental question to be answered by future research is: why did the brown bear survive to the present day, while the cave bear did not?" said Anthony Stuart, the other author at the Natural History Museum in London.
Answers might involve differing diets, hibernation habits, geographical ranges, habitat and perhaps hunting by people, he said
By Alister Doyle, Environment Correspondent
The largely vegetarian bears, weighing up to a tonne and bigger than modern polar bears or Kodiak bears, apparently died off as a sharp cooling of the climate led to a freeze that killed off the fruits, nuts and plants they ate.
The bears vanished 27,800 years ago, or about 13,000 years earlier than previously believed, the scientists in Austria and Britain said in a study of bear remains using radiocarbon dating including at hibernation sites in the Alps.
"There is little convincing evidence so far of human involvement in extinction of the cave bear," they wrote in the journal Boreas. Some past reports have suggested that the cave bears' demise was linked to over-hunting.
Cave bears ranged from what is now Spain to the Ural Mountains, and were one of several large creatures -- such as the woolly mammoth, woolly rhinoceros, giant deer and cave lion -- to vanish during the Ice Age that ended 10,000 years ago.
"Our work shows that the cave bear ... was one of the earliest to disappear," Martina Pacher, one of the co-authors at the University of Vienna, said in a statement.
"Other, later extinctions happened at different times within the last 15,000 years," she said. Previous studies had errors in dating samples and sometimes confused remains of cave bears with those of brown bears, which still survive.
"A fundamental question to be answered by future research is: why did the brown bear survive to the present day, while the cave bear did not?" said Anthony Stuart, the other author at the Natural History Museum in London.
Answers might involve differing diets, hibernation habits, geographical ranges, habitat and perhaps hunting by people, he said
By Alister Doyle, Environment Correspondent
Sunday, November 23, 2008
Scientists Say Copernicus' Remains, Grave Found
Researchers said Thursday they have identified the remains of Nicolaus Copernicus by comparing DNA from a skeleton and hair retrieved from one of the 16th-century astronomer's books. The findings could put an end to centuries of speculation about the exact resting spot of Copernicus, a priest and astronomer whose theories identified the Sun, not the Earth, as the center of the universe.
Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull, missing the lower jaw, his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.
The reconstruction shows a broken nose and other features that resemble a self-portrait of Copernicus, and the skull bears a cut mark above the left eye that corresponds with a scar shown in the painting.
Moreover, the skull belonged to a man aged around 70 — Copernicus's age when he died in 1543.
"In our opinion, our work led us to the discovery of Copernicus's remains but a grain of doubt remained," Gassowski said.
So, in the next stage, Swedish genetics expert Marie Allen analyzed DNA from a vertebrae, a tooth and femur bone and matched and compared it to that taken from two hairs retrieved from a book that the 16th-century Polish astronomer owned, which is kept at a library of Sweden's Uppsala University where Allen works.
"We collected four hairs and two of them are from the same individual as the bones," Allen said.
Gassowski is head of the Archaeology and Anthropology Institute in Pultusk, in central Poland, and Allen works at the Rudbeck Laboratory of the Genetics and Pathology Department of Uppsala University.
Copernicus was known to have been buried in the 14th-century Frombork Cathedral where he served as a canon, but his grave was not marked. The bones found by Gassowski were located under floor tiles near one of the side altars.
Gassowski's team started his search in 2004, on request from regional Catholic bishop, Jacek Jezierski.
"In the two years of work, under extremely difficult conditions — amid thousands of visitors, with earth shifting under the heavy pounding of the organ music — we managed to locate the grave, which was badly damaged," Gassowski said.
Copernicus is believed to have come up with his main idea of the Sun at the center of the universe between 1508 and 1514, and during those years wrote a manuscript commonly known as Commentariolus (Little Commentary).
His final thesis was only published, however, in the year of his death. His ideas challenged the Bible, the church and past theories, and they had important consequences for future thinkers, including Galileo, Descartes and Newton.
Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
By MONIKA SCISLOWSKA Associated Press Writer
WARSAW, Poland November 20, 2008
Polish, Swedish scientists say they have identified Copernicus' remains, grave
Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull, missing the lower jaw, his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.
The reconstruction shows a broken nose and other features that resemble a self-portrait of Copernicus, and the skull bears a cut mark above the left eye that corresponds with a scar shown in the painting.
Moreover, the skull belonged to a man aged around 70 — Copernicus's age when he died in 1543.
"In our opinion, our work led us to the discovery of Copernicus's remains but a grain of doubt remained," Gassowski said.
So, in the next stage, Swedish genetics expert Marie Allen analyzed DNA from a vertebrae, a tooth and femur bone and matched and compared it to that taken from two hairs retrieved from a book that the 16th-century Polish astronomer owned, which is kept at a library of Sweden's Uppsala University where Allen works.
"We collected four hairs and two of them are from the same individual as the bones," Allen said.
Gassowski is head of the Archaeology and Anthropology Institute in Pultusk, in central Poland, and Allen works at the Rudbeck Laboratory of the Genetics and Pathology Department of Uppsala University.
Copernicus was known to have been buried in the 14th-century Frombork Cathedral where he served as a canon, but his grave was not marked. The bones found by Gassowski were located under floor tiles near one of the side altars.
Gassowski's team started his search in 2004, on request from regional Catholic bishop, Jacek Jezierski.
"In the two years of work, under extremely difficult conditions — amid thousands of visitors, with earth shifting under the heavy pounding of the organ music — we managed to locate the grave, which was badly damaged," Gassowski said.
Copernicus is believed to have come up with his main idea of the Sun at the center of the universe between 1508 and 1514, and during those years wrote a manuscript commonly known as Commentariolus (Little Commentary).
His final thesis was only published, however, in the year of his death. His ideas challenged the Bible, the church and past theories, and they had important consequences for future thinkers, including Galileo, Descartes and Newton.
Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
By MONIKA SCISLOWSKA Associated Press Writer
WARSAW, Poland November 20, 2008
Polish, Swedish scientists say they have identified Copernicus' remains, grave
Friday, November 14, 2008
First Extrasolar Planets Caught On Camera
Morning Edition, November 14, 2008 · Astronomers are getting their first real glimpses of planets in orbit around distant stars.
Over the past decade, more than 300 otherworldly worlds have been detected indirectly — typically their gravitational pull makes their host-stars wobble and astronomers can pick up that wobble. But the most recent planet discoveries are actual photo-ops.
For the first time, scientists have produced images of multiple planets orbiting a star other than our own sun. There have been three reports in the past two months purporting to show images of planets in solar systems around nearby stars.
Science Express published two of the new finds online Thursday. One involves a planet that appears to be orbiting just inside a giant ring of gas that encircles a star known as Fomalhaut, a mere 25 light-years from Earth. Paul Kalas of the University of California, Berkeley, suspects the planet is shepherding the star's massive gas ring and keeping it organized, much the way "shepherd moons" circle the rings of Saturn and keep them tidy.
The planet, dubbed Fomalhaut b, is a gas giant that is much bigger than Jupiter and apparently is surrounded by rings of its own. It's more than 100 times farther from its star than Earth is from the sun.
Meanwhile, an international team of astronomers say they've seen not just a single planet, but a small solar system around a star called HR 8799 (The name might sound like a personnel form, because astronomers sometimes can't decide whether to be scientific or romantic.)
These three planets in this system also appear to be gas giants, and all are at least five times bigger than Jupiter. Their orbits aren't too different from the orbits of our own outermost planets. And that makes this solar system somewhat like our own — though the star and its planets are much younger than our 5 billion-year-old solar system.
"Not only is it exciting just because we have pictures for the first time, but also because these pictures are revealing an entirely new population of planets that were not accessible to the previously used method for planet detection," says Ray Jayawardhana, an astronomer at the University of Toronto. He was part of a team that in September announced yet another image of what it claims is a planet at a nearby star.
But astronomers have not found what they would dearly like to see: an earth-like planet around a sun-like star.
"That's a little ways away, I'm afraid," Jayawardhana says.
We'll probably have to wait for the space telescope that will replace Hubble sometime in the coming decade.
Over the past decade, more than 300 otherworldly worlds have been detected indirectly — typically their gravitational pull makes their host-stars wobble and astronomers can pick up that wobble. But the most recent planet discoveries are actual photo-ops.
For the first time, scientists have produced images of multiple planets orbiting a star other than our own sun. There have been three reports in the past two months purporting to show images of planets in solar systems around nearby stars.
Science Express published two of the new finds online Thursday. One involves a planet that appears to be orbiting just inside a giant ring of gas that encircles a star known as Fomalhaut, a mere 25 light-years from Earth. Paul Kalas of the University of California, Berkeley, suspects the planet is shepherding the star's massive gas ring and keeping it organized, much the way "shepherd moons" circle the rings of Saturn and keep them tidy.
The planet, dubbed Fomalhaut b, is a gas giant that is much bigger than Jupiter and apparently is surrounded by rings of its own. It's more than 100 times farther from its star than Earth is from the sun.
Meanwhile, an international team of astronomers say they've seen not just a single planet, but a small solar system around a star called HR 8799 (The name might sound like a personnel form, because astronomers sometimes can't decide whether to be scientific or romantic.)
These three planets in this system also appear to be gas giants, and all are at least five times bigger than Jupiter. Their orbits aren't too different from the orbits of our own outermost planets. And that makes this solar system somewhat like our own — though the star and its planets are much younger than our 5 billion-year-old solar system.
"Not only is it exciting just because we have pictures for the first time, but also because these pictures are revealing an entirely new population of planets that were not accessible to the previously used method for planet detection," says Ray Jayawardhana, an astronomer at the University of Toronto. He was part of a team that in September announced yet another image of what it claims is a planet at a nearby star.
But astronomers have not found what they would dearly like to see: an earth-like planet around a sun-like star.
"That's a little ways away, I'm afraid," Jayawardhana says.
We'll probably have to wait for the space telescope that will replace Hubble sometime in the coming decade.
Saturday, November 01, 2008
Space station trash plunging to Earth
A piece of space station trash the size of a refrigerator is poised to plunge through the Earth's atmosphere late Sunday, more than a year after an astronaut tossed it overboard.
NASA and the U.S. Space Surveillance Network are tracking the object — a 1,400-pound (635-kilogram) tank of toxic ammonia coolant thrown from the international space station — to make sure it does not endanger people on Earth. Exactly where the tank will inevitably fall is currently unknown, though it is expected to re-enter Earth's atmosphere Sunday afternoon or later that evening, NASA officials said.
"This has got a very low likelihood that anybody will be impacted by it," said Mike Suffredini, NASA's space station program manager, in an interview. "But still, it is a large object and pieces will enter and we just need to be cautious."
NASA astronaut Clayton Anderson threw the ammonia tank from the tip of the space station's Canadian-built robotic arm during a July 23, 2007, spacewalk. He tossed away an unneeded video camera stand overboard as well, but that 212-pound (96-kilogram) item burned up harmlessly in the atmosphere early this year, Suffredini said.
NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces (40 grams) to nearly 40 pounds (17.5 kilograms).
If they reach all the way to land, the largest pieces could slam into the Earth's surface at about 100 mph (161 kilometers per hour). But a splashdown at sea is also possible, as the planet is two-thirds ocean.
"If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn't get too close to it," Suffredini said.
Known as the Early Ammonia Servicer, or EAS, the coolant tank is the largest piece of orbital trash ever tossed overboard by hand from the space station. Larger unmanned Russian and European cargo ships are routinely destroyed in the Earth's atmosphere over the Pacific Ocean after their space station deliveries, but those disposals are controlled and preplanned.
The recent destruction of the European Space Agency's Jules Verne cargo ship was eagerly observed by scientists hoping to glean new information on how objects behave as they enter Earth's atmosphere. Observers aboard two chase planes caught photographs and video of the double-decker bus-sized spacecraft's demise, but no such campaign is possible with the returning ammonia tank.
The last object to re-enter Earth's atmosphere with prior notice was a small asteroid the size of a kitchen table that exploded in midair as it flew over Africa on Oct. 7.
It's taken more than year for the ammonia tank to slowly slip down toward Earth due to atmospheric drag. During its time aboard the station, the tank served as a coolant reservoir to boost the outpost's cooling system in the event of leaks. Upgrades to the station last year made the tank obsolete, and engineers were concerned that its structural integrity would not withstand a ride back to Earth aboard a NASA space shuttle.
Instead, they tossed it overboard, or "jettisoned" it in NASA parlance.
Suffredini said that while astronauts have accidentally lost a tool or two during spacewalks, the planned jettison of larger items is done with the utmost care to ensure the trash doesn't hit the station or any other spacecraft as it circles the Earth. Engineers also make sure the risk to people on Earth is low, as well.
"As a matter of course, we don't throw things overboard haphazardly," Suffredini said. "We have a policy that has certain criteria we have to meet before you can throw something overboard."
In the event the tank re-enters over land, NASA advised members of the public to contact their local authorities, or the U.S. Department of State via diplomatic channels if outside the U.S., if they believe they've found its remains.
© 2007 Space.com. All rights reserved. More from Space.com
Tank of toxic ammonia coolant thrown from station more than a year ago
By Tariq Malik
Senior editor
NASA and the U.S. Space Surveillance Network are tracking the object — a 1,400-pound (635-kilogram) tank of toxic ammonia coolant thrown from the international space station — to make sure it does not endanger people on Earth. Exactly where the tank will inevitably fall is currently unknown, though it is expected to re-enter Earth's atmosphere Sunday afternoon or later that evening, NASA officials said.
"This has got a very low likelihood that anybody will be impacted by it," said Mike Suffredini, NASA's space station program manager, in an interview. "But still, it is a large object and pieces will enter and we just need to be cautious."
NASA astronaut Clayton Anderson threw the ammonia tank from the tip of the space station's Canadian-built robotic arm during a July 23, 2007, spacewalk. He tossed away an unneeded video camera stand overboard as well, but that 212-pound (96-kilogram) item burned up harmlessly in the atmosphere early this year, Suffredini said.
NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces (40 grams) to nearly 40 pounds (17.5 kilograms).
If they reach all the way to land, the largest pieces could slam into the Earth's surface at about 100 mph (161 kilometers per hour). But a splashdown at sea is also possible, as the planet is two-thirds ocean.
"If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn't get too close to it," Suffredini said.
Known as the Early Ammonia Servicer, or EAS, the coolant tank is the largest piece of orbital trash ever tossed overboard by hand from the space station. Larger unmanned Russian and European cargo ships are routinely destroyed in the Earth's atmosphere over the Pacific Ocean after their space station deliveries, but those disposals are controlled and preplanned.
The recent destruction of the European Space Agency's Jules Verne cargo ship was eagerly observed by scientists hoping to glean new information on how objects behave as they enter Earth's atmosphere. Observers aboard two chase planes caught photographs and video of the double-decker bus-sized spacecraft's demise, but no such campaign is possible with the returning ammonia tank.
The last object to re-enter Earth's atmosphere with prior notice was a small asteroid the size of a kitchen table that exploded in midair as it flew over Africa on Oct. 7.
It's taken more than year for the ammonia tank to slowly slip down toward Earth due to atmospheric drag. During its time aboard the station, the tank served as a coolant reservoir to boost the outpost's cooling system in the event of leaks. Upgrades to the station last year made the tank obsolete, and engineers were concerned that its structural integrity would not withstand a ride back to Earth aboard a NASA space shuttle.
Instead, they tossed it overboard, or "jettisoned" it in NASA parlance.
Suffredini said that while astronauts have accidentally lost a tool or two during spacewalks, the planned jettison of larger items is done with the utmost care to ensure the trash doesn't hit the station or any other spacecraft as it circles the Earth. Engineers also make sure the risk to people on Earth is low, as well.
"As a matter of course, we don't throw things overboard haphazardly," Suffredini said. "We have a policy that has certain criteria we have to meet before you can throw something overboard."
In the event the tank re-enters over land, NASA advised members of the public to contact their local authorities, or the U.S. Department of State via diplomatic channels if outside the U.S., if they believe they've found its remains.
© 2007 Space.com. All rights reserved. More from Space.com
Tank of toxic ammonia coolant thrown from station more than a year ago
By Tariq Malik
Senior editor
Space Litter To Hit Earth Tomorrow
A refrigerator-sized tank of toxic ammonia, tossed from the international space station last year, is expected to hit earth tomorrow afternoon or evening. The 1,400-pound object was deliberately jettisoned — by hand — from the ISS's robot arm in July 2007. Since the time of re-entry is uncertain, so is the location.
"NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces (40 grams) to nearly 40 pounds (17.5 kilograms). ... [T]he largest pieces could slam into the Earth's surface at about 100 mph (161 kph). ...'If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn't get too close to it,' [a NASA spokesman] said."
Posted by kdawson on Saturday November 01, @05:39PM
from the leave-only-memories-take-only-footprints dept
"NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces (40 grams) to nearly 40 pounds (17.5 kilograms). ... [T]he largest pieces could slam into the Earth's surface at about 100 mph (161 kph). ...'If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn't get too close to it,' [a NASA spokesman] said."
Posted by kdawson on Saturday November 01, @05:39PM
from the leave-only-memories-take-only-footprints dept
Subscribe to:
Posts (Atom)