A devastating meteor strike wiped out many of Earth's early species, say Louisiana State University researchers who found traces of "shocked quartz," altered by a sudden wave of extremely high pressure, in ancient soil layers. According to the researchers, "This extinction happened 380 million years ago in what is called the middle Devonian Period. It was a time when only small plants, wingless insects, and spiders inhabited the land and everything else lived in the sea. About 40 percent of all species disappeared from the fossil record at this time. The extinction has been known to geologists for a long time, but this is the first time it has been tied to a meteor strike. This is also the oldest known impact that has been tied to a mass extinction." The episode joins other, more recent extinctions that have been tied to impacts, including the death of the dinosaurs 65 million years ago. Shock quartz has so far been linked only to meteor impacts and nuclear bomb explosions.
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It's the fear of a repeat performance that underlies NASA's Near-Earth Object Program. Established in 1998, its telescopic search is designed to discover 90 percent of the NEO population (comets or asteroids six tenths of a mile in diameter or larger that come within 28 million miles of the Earth's orbit) within 10 years. As of June 28, the project had found 2,402 near-Earth objects. The NEO Web site has loads of interesting information including near misses–either past or predicted–by these giant space rocks. You can also run an animation that tracks various objects as they make their way through the solar system.
Parents still might want to think twice before letting their kids stay up late playing video games. In the Journal of Applied Psychology, a Japanese team suggests that working in front a bright computer monitor late at night "suppresses the nocturnal changes in melatonin concentration and other elements of our biological clocks." In other words, all that nighttime video-game playing or Web surfing might result in a poor night's sleep. The study, say the scientists, helps explain a recent survey in Japan showing that 53.7 percent of Internet users there had "delayed bedtimes" and 45 percent of them had "shortened sleeping hours."
Of course, video-game playing isn't all bad. There was also that recent study out of the University of Rochester suggesting that video games can "give a person the ability to monitor more objects in their visual field and do so faster than a person who doesn't play such games." In one test, a small object flashed on the screen for just one one-hundred-sixtieth of a second. Gamers noticed the object far more often than nongamers. That kind of skill might make a gamer a better driver or a sharper soldier. The scientists say their work also suggests that action games could be a useful tool for rehabilitating visually impaired patients.
