ScienceShots

• Fern frenzy. About 100 million years ago, flowering plants took over Earth, crowding out pine trees, cycads, and other non-flowering plants that had dominated the landscape until that time. But there was an exception: leptosporangiate ferns--known for spore-forming organs that burst and fling out spores--continued to thrive. Today, they account for 9000 of the 11,000 non-flowering vascular plant species. By reconstructing fern evolution using DNA and fossil data from more than 400 species, researchers have shown that these ferns often found new homes among the branches of newly emerging tropical rainforests, where about 55 million years ago, they began to diversify into thousands of new treebound species. The results are described in the 7 July issue of the Proceedings of the National Academy of Sciences. (Photo: Eric Schuettpelz, Duke University)
• Iron or ice? In 1908, something exploded high above Tunguska, Siberia, and leveled a vast forest. Ever since, scientists have argued about whether it was a small asteroid or a fragement of a comet. Now, a study in press at Geophysical Research Letters uses the exhaust plume of NASA's space shuttle to argue for the comet hypothesis. Each shuttle launch emits hundreds of metric tons of water vapor into the atmosphere. Soon thereafter, the vapor condenses into ice crystals and creates beautiful displays called noctilucent clouds (see photo). Observers of the Tunguska explosion reported the same phenomenon, and modern estimates of the blast place its altitude at about 70 kilometers--exactly where the shuttle's exhaust creates clouds. (Photo: M. J. Taylor and C. D. Burton/CASS/Utah State University)
• Gotcha! Talk about a sneak attack. The tentacled snake (Erpeton tentaculatum), a small, aquatic reptile native to Southeast Asia, has found a way to fool unsuspecting fish into swimming into its jaws. As the fish swims by, the snake remains motionless in a "J" shape and sends sound waves from the middle of its body. The fish instinctively turns in the opposite direction, but because of the way the snake is oriented, the fish swims right into the snake's mouth. This particular way of tricking prey appears unique in the animal kingdom, the author reports in an upcoming issue of the Proceedings of the National Academy of Sciences. (Credit: Ken Catania)
• Boom! Sarychev Peak had just begun erupting for the first time in 2 decades as the International Space Station was passing overhead. On 12 June, an astronaut snapped this photo of Matua Island in the Kuril Archipelago, northeast of Japan. A shock wave of brown ash is pushing up the atmosphere, leading to the smooth white bubble of steam. Meanwhile, dense gray ash is racing down the slope of the volcano. The island is uninhabitated. (Photo: Johnson Space Center)
• Moonshot. This image of the lunar landscape, a single, high-definition television frame, marks one of the last moments of a Japanese spacecraft's mission. At about 3:25 a.m. Japan Time on 11 June, Kaguya ("Lunar Princess") smashed into the moon very close to the South Pole in an area permanently hidden from sunlight. Scientists consider the region an ideal location for water ice to have accumulated from comet impacts. The idea behind Kaguya's swansong, occurring after 21 months of lunar exploration from orbit, was to kick up enough material from its 1.6-kilometer-per-second impact that Earth-based astronomers might be able to examine the plume for the presence of vaporized water. That didn't happen, however, so whether a frozen lake covers the moon's bottom remains a mystery. (Photo: JAXA/NHK)
• Blimey! Ancient mammoths apparently lumbered across the British countryside much more recently than thought. A new analysis of woolly mammoth bones found in Shropshire, England, dates the remains to 14,000 years ago. That's 7000 years after the mammoths were presumed to have gone extinct in Western Europe, researchers report online 18 June in the Geological Journal. But it's still unclear why the mammoths died out in the first place. The best guess by researchers is that warming at the end of the last ice age caused English forests to flourish, thereby crowding out the grass-loving beasts. (Image: Clipart.com)
• No feathers here. You could easily mistake this fossil for a bird, and in life it would even have had a prominent beak like a parrot. But this 110-million-year-old, 1-meter-long creature named Psittacosaurus gobiensis is a member of the ceratopsians, such as Triceratops, which are unrelated to birds. The conundrum, as researchers report 17 June in the Proceedings of the Royal Society B, is that P. gobiensis has a jaw and tooth structure remarkably similar to a parrot's, meaning its diet probably consisted of nuts and hard fruits or their antecedents. But in terms of natural selection, this seems to be a case where a particular trait emerged, died off, and re-appeared farther along the evolutionary path. (Image: P. Sereno et al., Proceedings of the Royal Society B (2009))
• Outlier. This isn't some sea battle being waged off the European coast or even a giant flotilla of fishing vessels illuminated at night. It's a spectroscopic scan of a unique meteorite named Isheyevo, found near the Russian village of the same name in 2006. Unlike most meteorites, this one has more in common with comets than asteroids. The bright areas in the scan are rare, heavy nitrogen atoms associated with organic chemicals. These nitrogen atoms are 30,000 times more abundant in Isheyevo than in other meteorites, meaning the rock could not have originated among the inner planets, researchers report online 15 June in Proceedings of the National Academy of Sciences. Instead, the meteorite either encountered Earth after migrating inward from the extreme reaches of the solar system, or from another part of the galaxy altogether. (Image: G. Briani et al./LMCM)
• Heavyweight. Spider silk contracts like a muscle, and it can lift weights, too. That's the conclusion of a new study wherein researchers alternately subjected the material to dry and wet air, which caused it to relax and contract in a cyclical manner. To find out how much weight the strands could lift, the team attached pipette tips ranging to each fiber from 2 mg to 100 mg, and measured the amount they moved up and down as the fiber contracted. From this, the researchers calculated that a 1 mm-thick bundle of silk fibers could potentially lift 5 kg, while a 2 cm-thick bundle could lift 2 metric tons. The team reports in the 1 July issue of The Journal of Experimental Biology that silk's power could be harnessed to drive mechanical devices in robots, sensors, and micro-machines. (Photo: Agnarsson et al., The Journal of Experimental Biology, 212 ((2009))
• Fast and flirty. At full tilt this Anna's hummingbird (Calypte anna) tries to impress his potential mate with some advanced aerial acrobatics. Reaching speeds of about 27 meters per second during courtship dives, the bird experiences a centripetal acceleration of nearly 10g. This is the highest g force ever measured for an animal in voluntary motion, excluding jet fighter pilots, a zoologist reports 10 June in the Proceedings of the Royal Society B. The researcher fooled male birds to perform in front of his high-speed video camera by placing a stuffed mount of a hummingbird female within their territory. The picture show is a compilation of the different stages of one courtship dive. (Photo: Christopher Clark)
• Flattened. Coral reefs are nature's modern art sculptures with pillars, massive boulders, and extensive branching formations that turn the sea bottom into a wonderland for much of the ocean's biodiversity. But an analysis of hundreds of reef surveys from 1969 through 2008 has concluded that in the Caribbean, dead, broken coral or small, weedy mounds are mostly what remain in 75% of the reefs, an increase in flattening from 20% in the 1970s. Disease, coral bleaching, and ocean acidification have taken their toll, eroding the coral and destroying the reef's complex architecture, researchers report 10 June in the Proceedings of the Royal Society B. The decline results in fewer fish for fishermen and an increased risk of coastal erosion and flooding. (Photo: Lorenzo Alvarez-Filip)
• Antigravity. Demonstrating the same capillary action that allows trees to pull water from roots to leaves, researchers have designed strips of metal that can pull water uphill. A pattern of nanoscale trenches, valleys, and pits carved on surface of various metals adhere to the liquid's molecules better than they adhere to each other, causing them to quickly spread out across the surface, even moving straight up. Changes in the nano-structure patterns can determine the fluid's path or change its direction, researchers report 2 June in Applied Physics Letters. The technology could open the door to new cooling techniques in electronics or to precisely directing fluids around medical diagnostic chips. (Photo: University of Rochester)
• Buzz off. How do you keep a 5-ton elephant out of your garden? Try bees. Although elephants have thick hides, their eyes and inner trunks are susceptible to bee stings; calves can even be killed by a swarm of bees. Playing on the pachyderm's fear, researchers installed bee hives around a Kenyan farm whose maize, potatoes, and beans were repeatedly raided by elephants. Researchers report in the June issue of the African Journal of Ecology that the hives reduced elephant crop raids by nearly half when compared with a neighboring farm. If employed on a large scale, the hives may reduce attacks on elephants and provide farmers with an extra source of income from honey and wax. (Photo: OU/Lucy King)
• Know your stars. Astronomers are celebrating the discovery of a rare stellar shadow dance called an eclipsing binary. The Canadian MOST space telescope has produced the longest, clearest view ever of Spica, a famous pair of massive blue dwarf stars just 260 light-years away in the constellation Virgo. A sharp dip in Spica's brightness every 4 days is the telltale sign that one of the pair is eclipsing the other from Earth's perspective, researchers report 3 June at an astronomy meeting in Santa Fe, New Mexico. Knowing this will allow astronomers to fill in some nagging unknowns, such as the stars' size and even their shape, which is thought to be more like balloons than spheres due to their powerful tidal pull on each other. (Photo: MPL3D)
• Unearthed. Scientists have discovered in nature what was once seen only in the laboratory: a quasicrystal. Ever since researchers first made the materials 25 years ago--with structures that fall somewhere between a highly-ordered crystal and randomly-structured glass--they've wondered whether nature was capable of creating them, too. In order to find out, researchers looked for rocks containing elements that compose the most commonly studied quasicrystal, which is made of aluminum, copper, and iron. A computer program that scanned for suspect quasicrystal patterns narrowed the search. Finally, the researchers found what they were seeking in a rock called khatyrkite, they report 5 June in Science. And thanks to the discovery, quasicrystals will now be classified as bona fide minerals. (Photo: Image courtesy of Science/AAAS)
• Mismatch. Call them Mike and Ike, or Click and Clack, or even Laurel and Hardy--just don't call them twins. Astronomers have found an extrasolar planet as big as the star it's orbiting. The planet, called VB 10 and located about 20 light-years away, is a few times more massive than Jupiter; the star, a red dwarf, carries only about a third of our sun's mass. In an upcoming issue of The Astrophysical Journal, astronomers say the discovery is important because it means that even red dwarfs, the most common type of star in the universe, can host planetary systems. More planetary systems means more chances of finding another Earth-like planet out there. (Image: NASA/JPL-Caltech)
• Glow. You wouldn't think that the bioluminescent action of microscopic sea creatures could be observed from space, but given sufficient numbers of those creatures and sufficiently sensitive instruments, that's exactly what can happen--with the bonus of presenting a dynamic portrait of the health of the oceans. This global image was compiled by NASA's Aqua satellite, which can detect the natural fluorescent light emitted by phytoplankton, the single-celled organisms that constitute the bedrock of the ocean food chain. By mapping and tracking the plankton's light output (the red zones indicate high concentrations), scientists can keep tabs on one of the most valuable creatures on the planet. (Image: Aqua/MODIS/Mike Behrenfeld/Oregon State University)

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