TOP 100 CAMPING SITES
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| Will National Monument Status Save the Hawaiian Monk Seals? Dear EarthTalk: What is the status of Hawaiian monk seals and how will the new national monument designation in the waters around the Hawaiian Islands affect them? -- Polly LaBarre, New York, NY [More] rss.sciam.com |
Rebel Republicans break rank to back House climate bill In a video posted on YouTube, Congressman Mark Kirk (R–Ill.) looks up from a 1300-page stack of papers and says, “I’m on page 587, reading about ‘Alternative Metrics and Threshold Review’ and I’ve got many more hours to go before the vote and a couple hundred more pages.” [More] rss.sciam.com |
Readers Respond to Avoiding the Big Choke--And More... Playtime for Everyone Yesterday while going through our mail, Scientific American Mind’s cover line jumped out at me: “ The Serious Need for Play . How it improves your creativity, emotional health--and cuts stress” [article by Melinda Wenner]. I was thrilled to see “play” on the cover. [More] rss.sciam.com |
What (Maybe) Didn't Kill the Dinosaurs: Comets The chunks of ice and dust that make their home in the Oort cloud, far beyond the orbit of Pluto, sometimes become dislodged and head into the solar system as streaky comets. Some disruptions, caused by passing stars and other interactions with the Milky Way galaxy, are severe enough to send Oort comets into orbits that buzz or even collide with Earth. New simulations have revealed a novel mechanism for their entry into our part of the solar system, a method that also suggests that comet showers may not have been strongly involved in major extinctions on Earth.Comet dynamics depend heavily on Jupiter and Saturn: their huge gravitational fields tend to keep objects away from Earth. Comets that manage to skirt Jupiter and Saturn, the conventional thinking goes, had to have originated in the outer reaches of the Oort cloud, where perturbations from outside the solar system can be felt most strongly and are writ large across vast cometary orbits that take hundreds of years to complete. Only during comet showers caused by close stellar passages, the theory holds, have extreme gravitational disruptions brought inner Oort cloud comets into the mix. [More] rss.sciam.com |
Tiny tyrannosaurs rewrite evolutionary rules Looming larger than a double-decker bus and baring teeth that have been likened to serrated bananas, Tyrannosaurus rex has long been considered one of the most fearsome creatures ever to have walked the earth. Other familiar tyrannosaurs, such as Albertosaurus and Tarbosaurus , were likewise terrifying in their size and bite--despite those absurd-looking but characteristic arms. But it turns out that not all tyrannosaurs have these hallmark features.This past fall paleontologists unveiled two tyrannosaurs new to science that are shaking up long-standing ideas about everyone’s favorite mega-predator. The finds are forcing researchers to reevaluate the origin of the tyrannosaur body plan and reconsider what they thought they knew about the diversity of this well-studied group. “Our view of tyrannosaur evolution has changed dramatically,” says doctoral student Stephen L. Brusatte of the American Museum of Natural History in New York City. [More] rss.sciam.com |