Monday, May 28, 2007

The Truth Behind This Month's Blue Moon

Thursday, May 31 brings us the second of two full Moons for North Americans this month. Some almanacs and calendars assert that when two full Moons occur within a calendar month, that the second full Moon is called the "Blue Moon."

The full Moon that night will likely look no different than any other full Moon. But the Moon can change color in certain conditions.

After forest fires or volcanic eruptions, the Moon can appear to take on a bluish or even lavender hue. Soot and ash particles, deposited high in the Earth's atmosphere can sometimes make the Moon appear bluish. Smoke from widespread forest fire activity in western Canada created a blue Moon across eastern North America in late September 1950. In the aftermath of the massive eruption of Mount Pinatubo in the Philippines in June 1991 there were reports of blue moons (and even blue Suns) worldwide.

Origin of the term

The phrase "Once in a blue Moon" was first noted in 1824 and refers to occurrences that are uncommon, though not truly rare. Yet, to have two full Moons in the same month is not as uncommon as one might think. In fact, it occurs, on average, about every 32 months. And in the year 1999, it occurred twice in a span of just three months!

For the longest time no one seemed to have a clue as to where the "Blue Moon Rule" originated. Many years ago in the pages of Natural History magazine, I speculated that the rule might have evolved out of the fact that the word "belewe" came from the Old English, meaning, "to betray." "Perhaps," I suggested, "the second full Moon is 'belewe' because it betrays the usual perception of one full moon per month."

But as innovative as my explanation was, it turned out to be completely wrong.

More mistakes

It was not until the year 1999 that the origin of the calendrical term "Blue Moon" was at long last discovered. It was during the time frame from 1932 through 1957 that the Maine Farmers' Almanac suggested that if one of the four seasons (winter, spring, summer or fall) contained four full Moons instead of the usual three, that the third full Moon should be called a "Blue Moon."

But thanks to a couple of misinterpretations of this arcane rule, first by a writer in a 1946 issue of Sky & Telescope magazine, and much later, in 1980 in a syndicated radio program, it now appears that the second full Moon in a month is the one that's now popularly accepted as the definition of a "Blue Moon."

This time around, the Moon will turn full on May 31 at 9:04 p.m. Eastern Daylight Time (6:04 p.m. Pacific Daylight Time).

But for those living in Europe, Africa, Asia and Australia, that same full Moon occurs after midnight, on the calendar date of June 1. So in these regions of world, this will not be second of two full Moons in May, but the first of two full Moons in June. So, if (for example) you live London, you'll have to wait until June 30 to declare that the Moon is "officially" blue.

Top 10 Cool Moon Facts
Sky Calendar & Moon Phases
Astrophotography 101

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

Original Story: The Truth Behind This Month's Blue Moon

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Friday, May 18, 2007

NEW NET THREAT: INFECTIOUS WEB PAGES

Don't click on attachments? Good. Always keep that firewall turned on? Even better. Stay away from the Internet's unsavory neighborhoods? Better still. Think you are protected?

Wrong.

Computer criminals are evolving their tactics to subdue your computer, experts say. Each time you invest more money and time in staying safe, the bad guys just find another way around your defenses. Their newest method may be the trickiest yet: Web pages booby-trapped with infectious computer code.

Such sites are popping up at an alarming rate, according to a new study issued by Google called “Ghost in the Browser.” (Adobe Acrobat required).

Unsuspecting Net users are victimized by simply doing what they do hundreds of times each day – visiting a Web page. Then, while the consumer browses content normally, a computer virus or Trojan horse program is silently installed.

In the study, Google found 300,000 Web sites laced with such malicious code, and another 700,000 suspicious sites. For perspective, the study found only 18,000 Web sites laced with adware.

So called drive-by downloads are not new, but criminals have seized on the tactic lately because their success rate with traditional e-mail viruses has tapered off thanks to improved software and consumer education. Avoiding e-mail viruses is fairly easy, as long as consumers following clear rules like "don't click on any attachments." But drive-by downloads are much more sinister, as no user interaction is required beyond opening an infected site in a Web browser.

Web 2.0 -- more risks

Dave Cole, a Symantec researcher, said even the tried-and-true advice to “stay out of the bad Web neighborhoods” doesn't work anymore. That’s largely because of the rapid increase in user-contribution Web 2.0-style sites -- sites like this blog that allow comments and other content to be uploaded. Hackers can often trick such Web sites into hosting their virulent computer code by using these tools to upload viruses. That means it's possible for consumers to visit what was once a harmless site -- say a blog they've looked at every day for a year without any problems -- and still become infected.

"Today it is not unlikely that you'll end up on a dangerous Web page even if you stick to good areas of ‘neighborhood,’” Cole said.

Once a consumer’s computer is infected by a drive-by download, it’s likely to become a zombie in an army of computers used by spammers to send out millions of unsolicited e-mails.

To see a demonstration of how spammers used hijacked computers to make money click on the video attached to this story.

The problem of hijacked computers – some believe as many as 100 million computers on the Net have been hijacked by hackers – read our recent three-part series, "Is Your Computer a Criminal."

The advent of drive-by downloads as the next important hacker tool puts search engines in the uncomfortable position of acting as a conduit between consumers and criminals. To counteract this threat, Google has quietly begun warning users whose searches turn up potentially malicious Web pages that "this site may harm your computer." The labeling began close to a year ago, said Google's Niels Provos, who co-authored the “Ghost in the Browser” report.

"The installation of software without user consent is something that can be detected easily," Provos said. The company ran billions of Web pages through a filter that looked for suspicious behavior. Of those, about 4.5 million pages tripped Google’s alarm, about 1 million contained some suspicious computer code and 450,000 were positively identified as dangerous. These sites now come with Google warning labels, and users must go to some trouble to actually visit the sites.

The practice has generated some controversy online, with a few writers criticizing Google for "policing" the Net and potentially censoring content. But Provos said the company has an appeals process for site owners who feel they have been improperly labeled as malicious, and that the firm is doing the right thing to keep users safe.

"We are taking the security of our users very seriously," Provos said. "No matter where the content comes from.”

Red Tape wrestling tips: Drive-by downloads are treacherous, but there are ways to minimize the likelihood that your computer will get hit. Provos suggests that computer users should:

• Use antivirus software and firewalls, along with services that automatically patch software like Windows. They won't keep you from visiting infectious Web sites, but they can stop the virus or Trojan horse from wreaking havoc on your computer.

• Visit only Web sites you trust. You can still become infected, but your odds of staying safe are better.

• Take the added precaution of running the Web browser in a "virtual machine," which isolates the browser software from the rest of the computer. Even if consumers visit a malicious site with a browser running in a virtual machine, the infection will not spread to the rest of the PC. Microsoft offers virtual PC software for both Macintosh and Windows, which can be downloaded for free.

Thursday, May 17, 2007

Polar depths yield hundreds of weird species

Carnivorous sponges, blind creepy-crawlies adorned with hairy antennae and ribbed worms are just some of the new characters found to inhabit the dark abysses of the Southern Ocean, an alien abode once thought devoid of such life.

Recent expeditions have uncloaked this polar region, finding nearly 600 species of organisms never described before and challenging some assumptions that deep-sea biodiversity is depressed. The findings also suggest that all of Earth's marine life originated in Antarctic waters.

Scientists had assumed that the deep sea of the South Pole would follow similar trends in biodiversity documented for the Arctic. "There are less species in the Arctic than around the equator," said one of the scientists behind the study, Brigitte Ebbe, a taxonomist at the German Center for Marine Biodiversity Research. "People assumed that it would be the same if you went from the equator south, but it didn't prove to be true at all."

The findings, reported this week in the journal Nature, provide a more accurate picture of creatures in the southern deep sea and shed light on the evolution of biodiversity in the deep ocean, including ancient colonization dating back 65 million years.

"The Antarctic deep sea is potentially the cradle of life of the global marine species," said lead author Angelika Brandt of the Zoological Institute and Zoological Museum at the University of Hamburg.

Deep dwellers
Between 2002 and 2005, an international team of scientists completed three research expeditions to the Weddell Sea aboard the German vessel Polarstern. Part of the Southern Ocean, the Weddell Sea is bounded by an Antarctic bulge called Coats Land and the Antarctic Peninsula.

Ernest Shackleton's Endurance was trapped and crushed by ice in this sea in 1915. (Shackleton and his entire crew survived. Shackleton died in 1922 of a heart attack on a different Antarctic expedition).

Part of the ANDEEP (Antarctic Benthic Deep-Sea Biodiversity) project, the team collected biological samples from regions between about 2,000 and 21,000 feet below the surface of the Weddell Sea and nearby areas.

In addition to cataloging biodiversity, the scientists aimed to determine how species intermingled within and between the deep and shallower waters and whether continental-shelf organisms colonized the deep ocean or vice versa.

The Weddell Sea is part of a vast ocean current and a critical source of deep water and possibly a mode of transport to the rest of the Southern Ocean. Some of the scientists' findings indicate species originating in a single water domain did migrate to the Southern Ocean, and some even trekked across the globe and now inhabit the Arctic waters. Many of the organisms have relatives in both the nearby shallower waters and even in other ocean basins.

Species finds included 674 species of isopods, a group of crustaceans, 80 percent of which were new to science. Some of the isopods and marine worms spotted on the continental shelf sported clues of their deep-water past. "On the shelf, the animals have eyes because they can see. There's light in the water. In the deep sea you don't really need them, so many animals get rid of their eyes," Ebbe told LiveScience.

"There were some [species] that are very closely related to eyeless isopods, and they are now living on the shelf. So that's an indication they have moved upward," Ebbe said.

Water travel
Many species living in the deep abyss of the Weddell Sea showed strong links with other oceans, particularly organisms like amoebae that can disperse their larvae over long distances. Poor dispersers — including some isopods, nematode worms and seed shrimps — stayed close to home in the Southern Ocean.

One particularly cosmopolitan group included the foraminifera, or tiny single-celled organisms covered with relatively decorative shells. Genetic analyses showed that three foraminifera species (Epistominella exigua, Cibicidoides wuellerstorfi and Oridorsalis umbonatus) found in both the Weddell Sea and the Arctic Ocean were nearly identical.

"They literally found some of [the foraminifera] from pole to pole, which is really amazing," Ebbe said.

Time to diversify
In terms of the soaring biodiversity, the scientists suggest organisms in the Antarctic have been around for a long time, giving them time to diversify.

"The Southern Ocean has been like it is pretty much for the last 40 million years, and it has been isolated," Ebbe said. "So the communities have had a long, long time to evolve. In the Arctic, it is much different."

In the geologic past Antarctica belonged to a giant land mass called Gondwana that straddled the equator. The land mass, which also included Africa, Australia, India and the tip of South America, started breaking apart more than 100 million years ago. About 60 million years ago, Antarctica had drifted close to the South Pole, and oceans rise to fill the gaps between Antarctica and Africa and India. By 40 million years ago, the continent had become completely encircled by oceans, now called the Southern Ocean.

"What was once thought to be a featureless abyss is in fact a dynamic, variable and biologically rich environment," said study team member Katrin Linse, a marine biologist with the British Antarctic Survey.

"Finding this extraordinary treasure trove of marine life is our first step to understanding the complex relationships between the deep ocean and distribution of marine life," she said.

© 2007 LiveScience.com. All rights reserved.


By Jeanna Bryner
Updated: 9:56 p.m. ET May 16, 2007


Antarctic waters served as a cradle for marine life, researchers say

NASA touts aging Hubble telescope's successor

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

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

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

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