NASA’s Fermi telescope has discovered 12 previously unseen pulsars — the tip of the iceberg, researchers say — and has the potential to unlock new secrets of supernova explosions.
The Fermi/LAT collaboration announced the discovery of 12 pulsars on Tuesday that have never been observed before, along with 17 that were previously identified by their radio waves.
In addition, the mission has detected six so-called millisecond radio pulsars, a new class of extended-life pulsars which rotate at breakneck paces after gobbling up their aging companion stars, and can live a billion years or more.
Normal pulsars last only a million years or so after a high mass star explodes into a supernova, and spawns them.
A total of 1800 pulsars had previously been discovered by their radio emissions, but gamma rays are turning out to be much more revealing, said Fermi/LAT collaborator and Stanford physicist Roger Romani.
“The radio is just a slide show. We’re looking at objects that are vastly more powerful” than their radio emissions alone had shown, he said.
Romani and Fermi team member Alice Harding, a theorist at NASA’s Goddard Space Flight Center, presented the new findings at a press conference as part of the 213th American Astronomical Society meeting in Long Beach, California.
Harding said Fermi, formerly known as the GLAST mission, has dramatically outpaced their expectations.
“We predicted we’d see this many gamma ray pulsars after a year, or several years. We saw CTA-1 in the first light data,” she said, referring to Fermi’s very first gamma-ray only pulsar, announced in October.
“It looks like everywhere were looking, we see pulsars,” Harding added. “It’s cool.”
It’s a wonderful thing when kids are invited to get excited about science. And with the launch of the space shuttle Endeavor on Friday, NASA is throwing open the door.
As it heads to the International Space Station, Endeavor will be toting living things besides seven astronauts: butterfly larvae, young spiders, and the nectar and fruit flies that will feed them.
And hundreds of school kids in Colorado will be watching.
Bioserve Space Technologies, at the University of Colorado at Boulder, will downlink videos and images of the spiders and butterflies from the space station to its partners: the Denver Museum of Nature and Science, the Butterfly Pavilion in Westminster, Colo., and the Baylor College of Medicine.
Meanwhile, elementary and middle school students in Colorado will be observing populations of the same creatures on Earth.
The first of two experiments will contrast the life cycles of painted lady butterflies in space and on Earth. The second will compare the ability of an orb-weaving spider to spin webs and catch food on Earth, and in the nearly weightless environment of space.
Eileen Patrick is a librarian at Rocky Mountain Elementary School in Westminster, Colorado near Denver. As of Thursday, her butterfly larvae were incubating in her bathroom. If they survive the weekend, she’ll begin her experiment next week with the 30 or so 4th and 5th graders who attend her after-school, extra-curricular science program.
Patrick says she hosts the science experiments — her aspiring engineers were building go-carts on Thursday — to supplement classroom science that’s largely consumed with material to meet state testing requirements.
“It’s still true that the fields of math, engineering and science under-represent girls, women, minorities, kids who come from at-risk backgrounds,” she said. And in large part, those are the students she knows.
“I think if you want to raise the next generation of scientists, you don’t wait until they’re halfway through college to engage them in science, to fire them up,” she said. “Live animals are immediately fascinating and engaging to kids.”
Just returned from a fantastic trip to some national parks in the Four Corners area. I was on a travel assignment for a magazine and photos weren’t part of the job. I couldn’t help myself, though! Every photo I shot tightened the Southwest’s grip on my heart. I’m not sure how long I’ll be able to stay gone. But for now, I’m back in Tennessee, and resuming the daily grind … The photos are in a Picasa album, here. Enjoy!
Silly astronauts. Space travel is for tardigrades!
The world’s space agencies go to great lengths to protect human beings entering the deep frozen vaccuum of space. The prevailing belief has been that nothing could survive the ultra-cold, oxygen-deprived and radiation-intense conditions beyond Earth’s atmosphere.
Enter tardigrades: oblong invertebrates about a millimeter in length that can visit space, return to Earth, and go on living as usual.
Lead author Ingemar Jönsson, an ecologist at Kristianstad University College, and his colleagues have published a paper in the September 9 issue of Current Biology, a Cell Press journal, showing that tardigrades, also called water-bears, survived all of the challenges of space when they orbited Earth aboard the FOTON-M3 spacecraft launched by the European Space Agency last fall.
Jönsson and his colleagues were most surprised at the “complete lack of effects on survival and reproduction after exposure to the extremely dehydrating conditions of space vacuum,” he wrote in an email. “This shows that tardigrades can maintain the integrity of their cells even under the most severely dry conditions.”
On Earth, water bears live among lichens and mosses which often dry up. They are known to rehydrate after years of dry dormancy, and go on with their lives. And apparently, the tiny creatures can also weather vacuum conditions, temperatures near absolute zero, and — to some extent — solar UV radiation more than 1,000 times the level on Earth’s surface.
On Earth, UV radiation has been linked with changes to a cell’s genetic material. So, while about 10 percent of the tardigrades even reproduced after intense UV exposure, Jönsson said more work remains to see what’s happening on the inside.
“What is needed now is research on the cellular and molecular changes taking place when tardigrades are exposed to extreme dehydration and radiation,” he said. “Then we may begin to understand more about the mechanisms behind the tolerances of tardigrades.”
Images and more information about the ever-hardy tardigrades can be found here. For more about Jönsson’s work, visit his research website. (Be sure to select English language at top, if applicable.)
I enjoy writing about astronomy exactly for the reason I once feared it: there’s so much we don’t know. There’s rarely any shame in asking about the nature of a black hole, for example, because scientists are grappling with it too. Usually, if I get confused while writing an astronomy story, it’s because I’ve stumbled on an area of research that is still new, uncertain — and confusing! And those are the frontiers where the theories compete and the stories get fun.
This uncertainty has pervaded many lines of inquiry in recent headlines: discoveries on Saturn’s moon Titan, the nature of black holes and the contents of our solar system, with all its new members. And now, scientists are going back to the drawing board when it comes to the distinction between asteroids and comets.
Take this news flash out of the Planetary Science Institute (PSI) in Tucson, Arizona: “Research aims to unmask comets posing as asteroids.”
The difference between asteroids and comets was once clear. The story went that a giant cloud of gas and dust collapsed to create the solar system about 4.6 billion years ago. Asteroids formed from rock in the warmer, inner areas of the solar system; the so-called “asteroid belt” orbits between Mars and Jupiter. Comets were made of rock and ice and inhabited the colder, more distant regions.
Comets, historically, were defined by their tails. Because their wide orbits keep them for most of their lives in the frozen zone beyond Neptune, their surfaces are covered with dirty ice that vaporizes in fiery displays once they get closer to the sun. Comets are often much smaller than asteroids. The famed Hale-Bopp was thirty to fifty miles across. Halley boasted a ten-mile diameter. While many asteroids are big enough that gravity works to make them round, comets tend to have elongated shapes that get even more odd as the sun’s heat vaporizes their interior patches of ice.
But sometimes, a comet looks like an asteroid. Comet Halley could one day be an example. When it buzzed Earth in 1910, Halley made a dazzling appearance that inspired all kinds of poems and songs. But Halley didn’t sing its old song with quite as much gusto in 1986. Eventually, the Sun will burn off Halley’s volatile components and it’ll cease to be a spectacular show not because of its position but because there’s nothing left to vaporize. And therein lies one of the rubs in distinguishing asteroids and comets: “I expect Halley,” Flagstaff astronomer David Schleicher once said, “to finally get to the point when it looks like an asteroid.”
The research team at Tucson’s Planetary Science Institute, led by PSI astronomer Paul Abell, estimates that between five and 10 percent of Near Earth Objects could be comets impersonating asteroids. Some could be dying comets, and others could be dormant – with the potential to display comet-like traits after colliding with other objects.
Abell and his colleagues are using NASA’s Infrared Telescope Facility at the Mauna Kea Observatories in Hawaii and the MMT telescope on Mount Hopkins, south of Tucson, to revisit objects that have been labeled asteroids.
One imposter was already exposed: 2001 OG108, Lowell Observatory astronomers (in Flagstaff) first raised a flag on the object, formerly known as an asteroid. Other telescopes were aimed at it, and sure enough, detected a comet’s nucleus.
It’s useful to tell the difference partly because nearby comets could provide water and other materials become supply depots to support future space missions. And comets or asteroids could be threats to Earth if they collide with us — but comets could perhaps be more dangerous. Comets are structurally weak and likely to break up as they enter the atmosphere, leading to a heat and shockwave blast that would be much more devastating than the impact from an asteroid of the same size, the study authors say.
Finally, the PSI methods could reveal clues as to the origins of the comets it glimpses — most are thought to come from Pluto’s neighborhood, called the Kuiper Belt, or the theoretical Oort Cloud beyond it. Both regions are believed to contain clues in deep freeze that will help us understand the solar system’s origins.
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