Rusty Schweickart's Comments on 2009 Jupiter Impact

From Alan Boyle's article "Lessons from Jupiter's black eye", selections follow:

For years, [Apollo Astronaut and B612 Foundation leader Rusty] Schweickart and his colleagues at the B612 Foundation and the Association of Space Explorers have been urging the United Nations to take a more formal approach to assessing cosmic threats. Because the effects of an impact could be global, the deliberations about what to do in case an impact should have an international scope as well.

The first step is to identify potential threats: Just in the past week, Schweickart and others sent a letter urging the Australian government to restart funding for a near-Earth object search in the Southern Hemisphere. The government cut support to Spaceguard Australia in 1996, and since then asteroid-watchers have worried about the huge "blind spot" in their coverage area. (Fortunately, Australian amateur astronomers such as Anthony Wesley, who first spotted the Jupiter impact, have helped fill the gap.)

"Australia is arguably the most advanced country in the hemisphere," Philip Chapman, NASA's first Australian-born astronaut, was quoted as saying in The Australian. "Failure to contribute to the international effort is grotesquely irresponsible."

Schweickart told me in a follow-up e-mail that the jury is still out on the precise cause of the latest Jupiter impact:

"I think that the comet claim is simply a default position and perhaps a carryover from the Shoemaker-Levy 9 comet impact. Since no one saw it prior to impact, who knows whether it was a comet or asteroid. In my view, it's very much more likely to be an asteroid impact, simply due to the much higher population.

"As to why no one saw it prior to impact or knew it was going to impact… that’s pretty easy. Any asteroids that don’t come near Earth are difficult to see. The likelihood of spotting a 1-kilometer (this was probably not larger than that… most likely smaller) asteroid which circulates from the main belt out to halfway between Jupiter and Saturn is vanishingly small. The only way we’d have to know about this ahead is if it happened to be a near-Earth asteroid with an aphelion [maximum distance from the sun] greater than Jupiter's distance. That's a very small percentage of the near-Earth asteroid population.

"Still… any evidence of current impacts on any other body help to emphasize that it's only a matter of time till it's our turn. So the more the merrier!"

Link: MSNBC Cosmic Log article