In 2009, Canada plans to launch a suitcase-sized spacecraft that will be charged with spotting asteroids that could be on a collision course with Earth. There's already a big ground-based program underway. NASA regularly identifies and tracks asteroids, calculating the likelihood that they could at some point run into our pale blue dot.

A German newspaper reported last week that 13-year-old Nico Marquardt corrected a few glitches in NASA's estimates regarding the chances of a certain asteroid colliding with Earth. NASA concluded that the Apophis space rock has only a 1 in 45,000 chance of knocking into us, but this school-kid announced that the space agency had missed a few zeros, suggesting that the probability is closer to 1 in 450. And while quite a few news reports backed him up, even claiming that NASA agreed Marquardt was correct, the space agency is sticking to its estimates.

Make sure you don’t miss this one. Asteroid 2007 TU24 will be as close to Earth as it has been in 2,000 years, and it won’t get any closer in this century. With a diameter of around 800 feet, the space rock is large enough to cause some serious damage if it was ever to strike our pale blue dot, but astronomers say that is not a possibility.

In July, the space shuttle Discovery is slated to deliver two tons of hardware and supplies to the partially built International Space Station. This mission is paid for. As for the 16 more needed to finish assembly, as mandated by President George W. Bush two years ago in his Vision for Space Exploration policy, NASA is short by as much as $5 billion.

Despite its playful name, taken from Miguel de Cervantes’s classic novel, the European Space Agency’s Don Quijote mission is deadly serious. Slated for 2012, the $180-million mission will attempt to move one of two target asteroids, just identified this fall, by rear-ending it with a speeding spacecraft. Quijote is the first venture of its kind, although the B612 Foundation, a privately-funded nonprofit based in Tiburon, California, intends to launch a similar effort by 2015.

On December 27, 2004, while the world was focused on the Indian Ocean tsunami, a few astronomers were contemplating the possibility of an even deadlier disaster: that of a massive asteroid striking Earth. A fifth of a mile wide—heftier than the space rock that leveled a vast swath of Siberian forest in 1908—Near-Earth Asteroid 2004 MN4 had grabbed the attention of NASA scientists just before Christmas. They put the chance of an April 13, 2029, collision at 1 in 2,700 and two days later upped the odds to 1 in 165.