Saturday January 26, 2008
Stardust Update, Smith Cloud Collision, Jurassic Teen Moms, Antarctic Volcano, Ants Look Berry Nice, Hot Insect Sex
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Stardust Update
Electron microgram of stardust, courtesy NASA/Science Magazine
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Two years ago, NASA's Stardust Mission capsule returned to Earth, after gathering up particles from a comet's tail. Since then, researchers have been carefully analyzing the particles, trying to figure out just what Comet Wild2 was made of. It turns out that the comet material wasn't exactly what they'd expected. From particles that enter the Earth's atmosphere, we have a pretty good idea of what comet dust should look like. But what was found in the tail of Wild2 looked more like the dust you'd find in an asteroid. These results mean we need to revise our ideas about the differences between comets and asteroids. They may not be as different as we'd assumed. Dr. Hope Ishii, from the Lawrence Livermore National Laboratory, led the team that made the latest discovery.
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The Stardust Mission HomepageLivermore Media Release on the discoveryDr. Ishii's paper in Science MagazineEarlier Reports from Stardust on Quirks (Dec 16, 2006)Quirks Interview about Stardust's encounter with comet Wild2Smith Cloud Collision
An artist's conception of the Smith Cloud's trajectory, courtesy Bill Saxton, NRAO/AUI/NSF |
Not that you should be alarmed, but there's a gigantic object hurtling through space on a collision course with our galaxy, the Milky Way. Dr. Jay Lockman, Principle Scientist with the National Radio Astronomy Observatory in Green Bank, West Virginia, has been studying the mysterious object, called the Smith Cloud. First discovered in the 1960's, it has puzzled and intrigued astronomers who, until now, haven't had a particularly clear view. Dr. Lockman, using a new and extremely powerful radio telescope, was able to create high-definition images of the Smith Cloud which, it turns out, is a comet-shaped mass of hydrogen gas about 11, 000 light years long and 8, 000 light-years wide. It'll take another 10 to 20 million years before we really feel the crunch. But, when it finally does gets here, we can expect some fireworks.
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Jurassic Teen Moms
T. Rex Skull. Courtesy David Monniaux |
We tend to frown upon teen pregnancies but it wasn't always so. If you look back in history -- very far back -- it seems to have been the preferred reproductive approach. Sarah Werning, a PhD. student with the Museum of Paleontology at the University of California, Berkeley, has been studying the fossilized bones of three species of dinosaur, looking for clues to their age and reproductive physiology. She's found evidence that dinosaurs, like humans, were sexually mature while they were still adolescents. Unlike humans, however, teen pregnancy was probably desirable. Ms. Werning says that because many species, such as T-Rex, took up to 20 years to reach their adult weight and only lived to about 25 or 30, it made sense to get a early start on baby-making.
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Paper in the Proceedings of the National Academy of SciencesThe Museum of Paleontology at the University of California, BerkeleyPress release from UC Berkeley NewsAntarctic Volcano
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The Volcano is buried beneath an ice sheet similar to the one in the foreground of this shot, courtesy P. Carrara, USGS |
The British Antarctic Survey has been flying routine surveying missions over the western Antarctic ice sheets for several years. They've covered the area pretty thoroughly, so it might sound odd that they've only recently discovered a volcano. But, explains David Vaughan, a glaciologist with the BAS, it wasn't the easiest thing to spot, given that it's buried under several hundred meters of ice. Dr. Vaughan and his colleagues recently discovered the volcano when radar images revealed a layer of volcanic ash, like a layer of icing in a wedding cake, buried half-way down in the ice. Beneath the ice, says Dr. Vaughan, is a tuya, a flat-topped volcano, like the kind found under the glaciers in Iceland. It turns out that the volcano in Antarctica last erupted during the lifetime of Alexander the Great and sent a plume of ash and steam about 12 kilometers into the sky.
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The British Antarctic SurveyA press release from the BASDr. Vaughan's article in the journal Nature GeoscienceAnts Look Berry Nice
Normal workers and infected ants - courtesy S. Yanoviak |
Dr Stephen Yanoviak and his colleagues were studying a species of gliding ants in Panama when one of them noticed something strange. Some of the ants had bright red hind-ends, and were waving them in the air. When they examined the ants in the lab, they discovered that these ants were infected with parasitic nematode roundworms. Their research is now suggesting that these worms are causing the ants to change colour and change their behaviour, so they'll be mistaken for berries by birds, who then eat the ants and spread the nematode eggs around the jungle. The ants then bring the bird feces back to feed to their larvae, and the parasitic cycle continues. Dr. Yanoviak is a tropical insect ecologist at the University of Arkansas at Little Rock.
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News Release from UC Berkeley (with video)Dr Yanoviak's gliding ants page (with video)Systematic Parasitology, Feb. 2008Gliding Ants from Quirks & Quarks Feb. 19, 2005Hot Insect Sex
Ambush Bugs heat things up, courtesy D. Punzalan |
For many male creatures, the colour of their surface is a way to let females know just how sexy they are. This has led to developments such as the peacock's tail, the red breast of the robin, and many others. So when Dr. David Punzalan, from the University of Ottawa, began studying Ambush Bugs, he expected to find a similar situation. Male Ambush Bugs have dark brown or black patches on their heads, while females don't, and darker headed males are more successful at securing mates. But when Dr. Punzalan tested the females to see which males they preferred, the females didn't show any preference. What Dr. Punzalan went on to discover is that the darker males heat up faster on cold days, thanks to the dark patches acting like solar panels. This extra heating gives these males an advantage at finding the females and increasing their own reproductive success.
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Theme music copyright Raphaël Gluckstein. Creative Commons License by-nc-nd-2.0
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