Despite the long-held scientific conviction that the asteroid belt is being continually (though perhaps not literally) being atomized by collisions, no such impact has previously been witnessed. But on January 6th, the Hubble Space Telescope discerned a uniquely bizarre asteroid, P2010 A2, which appears to be the debris resulting from the collision of two previously unknown asteroids, most likely at speeds exceeding 11,000 miles per hour.
But there’s more. As NASA explains, “the asteroid belt contains abundant evidence of ancient collisions that have shattered precursor bodies into fragments. The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. One fragment of that ancient smashup may have struck Earth 65 million years ago, triggering a mass extinction that wiped out the dinosaurs. But no such asteroid-asteroid collision has been caught ‘in the act’ — until now.” (For further details, see this writeup from NASA. See also this item in Science Daily.)
With that connection to the KT extinction, this new discovery might well occasion another question: What’s the status of the Congressional mandate directing NASA to find 90 percent of all near-earth asteroids by 2020 that we discussed last August in Asteroid Watch Update? The answer: Not good.
The National Research Council has issued a preliminary version of the 150-page final report on the question entitled Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies. It is an interesting document which exhaustively explores the topic outlined by its title. For our purposes here, however, just two summary judgments are immediately relevant:
First, “Congress has mandated that NASA discover 90 percent of all near-Earth objects 140 meters in diameter or greater by 2020. The administration has not requested and Congress has not appropriated new funds to meet this objective. Only limited facilities are currently involved in this survey/discovery effort, funded by NASA’s existing budget.”
And second, “the current near-Earth object surveys cannot meet the goals of the 2005 George E. Brown, Jr. Near-Earth Object Survey Act directing NASA to discover 90 percent of all near-Earth objects 140 meters in diameter or greater by 2020.”