NASA Tests Heaviest Chute Drop Ever
Iddo Genuth writes "NASA and the US Air Force have successfully tested a new super-chute system aimed at reclaiming reusable Ares booster rockets. On February 28, 2009 a 50,000-pound dummy rocket booster was dropped in the Arizona desert and slowed by a system of five parachutes before it crashed to the ground. The booster landed softly without any damage. This was possibly the heaviest parachute drop ever, and NASA is planning to perform even heavier drops of up to 90,000 pounds in the next few months."
Afraid not. Parachutes work by increasing air drag. An incoming asteroid would be moving at something like 30 miles per second. The parachute would only have at most a couple of seconds to work. Having said that, if you had a boundary case of an asteroid that would lose a considerable portion of its energy to the atmosphere, but still have enough to cause significant property damage, then you could attach an inflatable balloon (I believe they call it a "ballute") to the front to increase the cross-sectional area of the asteroid, so it would lose more energy to the upper atmosphere. Those asteroids are probably too infrequent to bother planning for.