NASA Images Show Gamma Ray Bursts Across Milky Way

NASA researchers yesterday released images collected by a new telescope studying high-energy gamma rays. A combined image from 95 hours of the telescope's initial observations showed bursts of gamma rays glowing across the plane of the Milky Way.

The Gamma-Ray Large Area Space Telescope, renamed Fermi, was launched in June and is off to a promising start, NASA scientists said.

"I like to call it our extreme machine," said Jon Morse, the director of astrophysics for NASA. "It will help us crack the mysteries of these enormously powerful emissions."

Gamma rays are powerful light rays invisible to the naked eye. Because Earth's atmosphere absorbs gamma rays, they can be studied only from the edges of the visible universe.

Fermi is gathering data on gamma rays that originate near black holes and high-energy stars called pulsars.

Though much remains unknown, bursts of gamma rays are thought to be emitted from particles coming out of black holes and pulsars, said Peter Michelson, a Stanford physicist and a principal investigator for the mission.

"We don't yet understand the mechanism for how the particles that emit the gamma rays are accelerated," Michelson said. "We're not even sure what the nature of the particles are."

The study is a follow-up on work done by the Energetic Gamma-Ray Experiment Telescope, a mission that studied gamma rays from 1991 to 2000.

Fermi's technology allowed scientists to compile in days what took the first mission one year to do, said Steve Ritz, one of the project's scientists.

The telescope was renamed Fermi yesterday, after Italian physicist Enrico Fermi, because he is "today regarded as one of the top scientists of the 20th century," Ritz said.

The scientists hope that in the five to 10 years that it is in orbit, Fermi will be as remarkable as its namesake.

"This powerful space observatory will explore the most extreme of environments for us," Morse said.

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TV's 'Mythbusters' Tackle Moon Landing Hoax Claims

In 2005, Jamie Hyneman and Adam Savage, special effects experts better known by the title of their popular Discovery Channel series, "MythBusters", were asked during an interview about the myth they would most like to test provided an unlimited budget.

"Jamie and I have done the research, and figured that the only way to end the debate about the 'myth' of the Apollo moon landing is to go there," Savage replied to Slashdot, a technology news website, about the belief held by some that the United States faked the lunar landings.

Three years later, the Mythbusters are ready to share the results of their 'trip' as they devote their next show, airing on Wednesday, to the moon landing hoax claims.

"We built a hybrid rocket that was fueled by poo and nitrous oxide — thought we had enough Teflon tape on the seals but the stink got through anyway. Too bad that the footage got lost in transit to the editors," Hyneman told collectSPACE.com, explaining that their limited budget would not cover the cost of regular rocket fuel.

Of course, he was joking.

"Dude, I sooo wished we could have gone there," Savage admitted.

So, with their feet firmly planted on the Earth (at least for most of the time, but more on that later), Hyneman and Savage, along with fellow Mythbusters Tory Belleci, Kari Byron and Grant Imahara, set out to use science to 'bust' or confirm the truth behind the hoaxers' claims.

Low hanging fruit

Hoax believers have had 40 years to devise reasons why the Apollo moon landings must have been filmed in an Earth-based studio. As special effects experts, Hyneman felt they were well suited for the subject.

First however, they needed to choose which parts of the myth to test.

"We looked at the ones that for some reason or other, seemed most prevalent," Savage explained in an e-mail interview.

"We took the low hanging fruit," Hyneman added. "The key idea was that the footage that proved we were there was a special effect. Adam and I are experienced effects artists, so it was natural for us to dig into it."

"We wanted to tackle the ones that actually take some experimentation to prove," Savage said.

To narrow the field however, the Mythbusters sought the assistance of someone very familiar with debunking the moon hoax myth, or they would have if he had not come calling first.

"I was actually first involved with the Mythbusters early on, when I was contacted by one of their producers asking if I had any astronomical myths for them to bust," shared Dr. Phil Plait, a.k.a. "The Bad Astronomer", in an interview with collectSPACE.com. An astronomer who worked with the Hubble Telescope, Plait created a website, Bad Astronomy, aimed at dispelling astronomy and science based myths, including the moon hoax, which expanded into books and his recent appointment as president of the James Randi Educational Foundation.

"I made some suggestions but sadly they didn't use any of them," Plait said. "I guess most of them don't make very good TV."

That early interaction, which was followed by meeting the Mythbusters at conferences, led to Plait establishing a relationship with the show. So he was surprised when a fellow astronomer contacted him about the Mythbusters investigating the moon hoax.

"I hadn't heard anything about [this show] so I fired off an e-mail to Adam Savage and said, 'What gives?' and he e-mailed me back and said, 'Oh oh oh, we're going to ask you about this,'" recalled Plait.

"Over the course of a few days, they were on the phone with me and a lot of other people who knew about, for example, the properties of the lunar surface, to try to figure out not just the best way of debunking the moon hoax but the best aspects of it... so they wanted to know which ones that they had found were the ones that I ran into and what were the best ways to tackle them. It was actually a lot of fun."

Ultimately, Hyneman, Savage and the others settled on three major areas of the hoax: how light interacted with the lunar surface, how the astronauts appeared to move in the low gravity of the Moon and how items behaved in the airless void of space.

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Strange Clouds at the Edge of Space

August 25, 2008: When in space, keep an eye on the window. You never know what you might see.

Last month, astronauts on board the International Space Station (ISS) witnessed a beautiful display of noctilucent or "night-shining" clouds. The station was located about 340 km over western Mongolia on July 22nd when the crew snapped this picture:

Above: Noctilucent clouds photographed by the crew of the ISS: more.

Atmospheric scientist Gary Thomas of the University of Colorado has seen thousands of noctilucent cloud (NLC) photos, and he ranks this one among the best. "It's lovely," he says. "And it shows just how high these clouds really are--at the very edge of space."

He estimates the electric-blue band was 83 km above Earth's surface, higher than 99.999% of our planet's atmosphere. The sky at that altitude is space-black. It is the realm of meteors, high-energy auroras and decaying satellites.

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What are clouds doing up there? "That's what we're trying to find out," says Thomas.

People first noticed NLCs at the end of the 19th century after the 1883 eruption of Krakatoa. The Indonesian supervolcano hurled plumes of ash more than 50 km high in Earth's atmosphere. This produced spectacular sunsets and, for a while, turned twilight sky watching into a worldwide pastime. One evening in July 1885, Robert Leslie of Southampton, England, saw wispy blue filaments in the darkening sky. He published his observations in the journal Nature and is now credited with the discovery of noctilucent clouds.

Scientists of the 19th century figured the clouds were some curious manifestation of volcanic ash. Yet long after Krakatoa's ash settled, NLCs remained.

"It's a puzzle," says Thomas. "Noctilucent clouds have not only persisted, but also spread." In the beginning, the clouds were confined to latitudes above 50^o; you had to go to places like Scandinavia, Siberia and Scotland to see them. In recent years, however, they have been sighted from mid-latitudes such as Washington, Oregon, Turkey and Iran:

Above: Noctilucent clouds over Mt. Sabalan, a 15,784 ft extinct volcano in northwestern Iran. Photo credit: Siamak Sabet. [more]

"This year's apparition over Iran (pictured above) was splendid," says Thomas. The Persian clouds appeared on July 19th, just a few days before the ISS display, and were photographed from latitude 38^o N. "That's pretty far south," he says.

The genesis and spread of these clouds is an ongoing mystery. Could they be signs of climate change? "The first sightings do coincide with the Industrial Revolution," notes Thomas. "But the connection is controversial."

NASA is investigating. The AIM satellite, launched in April 2007, is now in polar orbit where it can monitor the size, shape and icy make-up of NLCs. The mission is still in its early stages, but already some things have been learned. Thomas, an AIM co-Investigator, offers these highlights:

1. Noctilucent clouds appear throughout the polar summer, are widespread, and are highly variable on hourly to daily time scales. A movie made from daily AIM snapshots shows the 2007 NLC season unfolding over the north pole: watch it.

Right: A daily snapshot of noctilucent cloud activity over the North Pole in 2007. Click on the image to set the scene in motion. Credit: AIM/Goddard Space Flight Center Scientific Visualization Studio.

2. There is a substantial population of invisible noctilucent clouds. Thomas explains: "NLCs are made of tiny ice crystals 40 to 100 nanometers wide—just the right size to scatter blue wavelengths of sunlight. This was known before AIM. The spacecraft has detected another population of much smaller ice crystals (<>

3. Some of the shapes in noctilucent clouds, resolved for the first time by AIM's cameras, resemble shapes in tropospheric clouds near Earth's surface. AIM science team members have described the similarities as "startling." The dynamics of weather at the edge of space may not be as unEarthly as previously supposed.

These findings are new and important, but they don't yet unravel the central mysteries:

Why did NLCs first appear in the 19th century?

Why are they spreading?

What is ice doing in a rarefied layer of Earth's upper atmosphere that is one hundred million times dryer than air from the Sahara desert?

AIM has just received a 3-year extension (from 2009 to 2012) to continue its studies. "We believe that more time in orbit and more data are going to help us answer these questions," says Thomas.

Meanwhile, it's a beautiful mystery. Just ask anyone at the edge of space.

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