Q) Can any living organism survive in outer space?
Peter Lai, Hartford, Connecticut 
Shove the bozo bogarting the Tang out the shuttle hatch and he'll simultaneously freeze, fry, and pop. Outer space has a temperature of about minus 434 Fahrenheit and is a stew of radiation that can boil blood and break up DNA. Multicellular life forms, from pumpkin seeds to possums—and, over long periods, astronauts inside spaceships, which don't provide protection from some radioactive rays—don't stand a chance. The only species with a shot are especially resilient lichens and bacteria, like Deinococcus radiodurans, discovered in ground beef in the 1950s, which has a thick cell wall and self-repairing DNA. And even it needs help. "A free-floating bacteria wouldn't last long," says Max Bernstein, an astrobiologist at NASA's Ames Research Center, in California. "But give it a bit of shielding, like a comet, where it can escape some rays, and it might endure thousands of years." Several controversial theories hold that such superbugs introduced life to Earth via comets or meteors—or the alien vessel that brought us Tom Cruise.

Pop Quiz

A frequent flier wonders why planes don't get struck by lightning. Actually, they get zapped a lot. If you've earned enough miles to know Smitty the bartender at the Virgin Clubhouse, you've probably been in a plane when it was hit. According to Ed Rupke, senior engineer at Lightning Technologies Inc., a Massachusetts company that specializes in aerospace protection, on average every commercial bird in the U.S. fleet is struck at least once a year. Thankfully, a bolt hasn't downed one since 1963. Modern FAA regulations stipulate that all commercial jets be lightning-proof, which most accomplish with a thick aluminum skin that conducts electricity out the tail or wings. Passengers often don't notice the jolt, though there's sometimes a bang or a bright burst. But global travelers, take note: In some developing nations, where planes that fly domestic routes may not be well maintained, strikes could still cause crashes. So the next time you fly from Kinshasa to Kisangani, check the weather before checking your bags.

Q) What's the most dangerous sport?
Julie Andersen, Santa Clara, California
New York State–based American Sports Data Inc. attempted to quantify playtime pain in a survey of 2002 U.S. athletic injuries. Leaving out ACL-snapping ball sports, the study found that for every 1,000 "exposures," snowboarders averaged 3.8 injuries, followed by skiers, with 3.0; surfers, with 1.8; and mountain bikers, with 1.2. For many people, though, danger equals death. In that department, according to sports industry groups, from 2000 to 2004 skiing killed an annual average of 32.6 participants, skydiving 29.2, mountaineering 25.4, kayaking 17.4, and snowboarding 10.4. Yet because the fatality stats don't factor in participation rates, it's hard to make fair comparisons, especially with fringe sports like BASE jumping. Or, you know, catapulting, which the Oxford, England, club Stunt Factory tried for a day in 2002, with fatal results: A member died when he landed short of the catch net.

Q) Where's the longest sheer drop-off in the world?
Laura Hutchins, Novato, California
There's no expert consensus, but our research indicates that the best point to toss your penny is the east face of Pakistan's Great Trango Tower, where Abe will plummet 4,400 feet before kissing dirt—though getting loose change up this elite-mountaineering test piece might be a stumbling point. Close behind Trango is the 4,100-foot vertical drop of Mount Thor, on Canada's Baffin Island. If you like wet drops, Venezuela's Angel Falls, highest in the world, showers the Churún River 3,212 feet below. Sorting out the tallest canyon wall is especially sticky, partly because the 16,000-plus-foot rim-to-river drops claimed for spots like Tibet's Tsangpo Gorge involve many short tiers; obsessive canyon photographer Richard Fisher believes the biggest wall drop is from the 1,931-foot Virgin Narrows, in Zion National Park. And if you're thinking the ultimate cliff might be under an ocean, think again—even in the 36,201-foot-deep Mariana Trench, sheer walls much over 1,000 feet are nonexistent.