DURING last year鈥檚 interminable US presidential campaign, some enterprising cynic made bumper stickers that read, 鈥淕iant Meteor 2016: Just end it already鈥�. That might now be a bit more likely.
The odds of an asteroid strike are low, but the effects would be catastrophic. So efforts to detect Earth-crossing objects have been ramped up 鈥� but we don鈥檛 know what we鈥檇 do if we found one.
One idea is to nudge it on to a harmless trajectory. To help us do that, we鈥檇 need to know what such bodies are made of (see 鈥�Hit threatening asteroids鈥� bright spots to deflect them from Earth鈥�). Two missions are planned to work on the problem: in 2022, the European Space Agency鈥檚 AIM craft should arrive at the asteroid Didymos, while NASA鈥檚 DART probe would crash into its companion, 鈥淒idymoon鈥�.
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But both are now in doubt: ESA鈥檚 members haven鈥檛 funded AIM, and DART is in limbo while the White House 鈥� which only recently released a document outlining the asteroid threat 鈥� decides what to do with NASA.
Given the ground-based risks we face (and axeing NASA鈥檚 earth science programme is definitely on the Trump agenda), asteroids might not seem high-priority. But it would be prudent to keep an eye on threats from space as well as on Earth. If Trump won鈥檛 back DART, ESA should go it alone.
This article appeared in print under the headline 鈥淜eep an eye on space鈥�
