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Since that meteor streaked through Russian skies on February 15th a lot of people have been thinking about asteroid defense.
If an inbound space rock were discovered early enough, a spacecraft could divert it any number of ways: by nuking it, smashing into it or tugging it off course. Then there’s an idea advocated by aerospace engineer David Hyland of Texas A&M University: just spray a coat of paint on the asteroid and let the sun do the rest.
The proposal relies on the so-called Yarkovsky effect. The hottest part of an asteroid—where it’s afternoon, asteroid local time—radiates the most heat into space, and those thermal photons impart a gentle recoil force. It’s incredibly subtle, but it’s constant, so the Yarkovsky effect can significantly change an asteroid’s orbit over time.
A new study in the journal Icarus identifies more than 20 asteroids that have been noticeably shifted by the Yarkovsky effect, naturally. [Davide Farnocchia et al., Near-Earth Asteroids with measurable Yarkovsky effect] Paint would enhance or reduce the effect by changing an inbound asteroid’s reflectance, thereby steering it away from us.
Currently no asteroids that we know of present a real threat to Earth. But it’s good to be prepared. Ask the dinosaurs.
—John Matson
[The above text is a transcript of this podcast.]
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5 Comments
Add CommentHow exactly does Mr. Hyland propose to 'spray paint' an asteroid? As I understand it, asteroids travel through space/vacuum at tens of kilometers a second. I'm a mechanical engineer, maybe an aerospace engineer like Mr Hyland can explain the method to me. (My guess that flying my spaceship along side it and sticking my arm out the window with a can of spray paint would not work.)
Reply | Report Abuse | Link to thisGary Shavit
I also wonder whether the asteroid could be reliably controlled in this way (assuming a painter can be found to do the job). It seems like topological variations might influence the absorption of energy and might induce some random rotation rather than nice, controlled deflection! Perhaps the painter will need to stick around, making touch-ups in perhaps a range of colors as conditions dictate...
Reply | Report Abuse | Link to thisA coat of paint will do nothing to shoe away a Comet! It's too volatile and will just bake off the paint.
Reply | Report Abuse | Link to thisAnd it will do NOTHING to shoe off this one:
http://science.nbcnews.com/_news/2013/02/26/17107085-comet-just-might-hit-mars-in-2014?lite
It's simply too big.
You are correct, gizmowiz. That is the likely reason why they only discuss this as a possible method of deflecting asteroids. I agree with jtdwyer, most likely it will be a far too complicated a process to guarantee the desired result. It may even backfire. What if an asteroid was really going to just miss us, but for the fact that we mistakenly nudged it just enough to hit the earth instead. I am also against the weaponization of space. No giant space paintball gun research!
Reply | Report Abuse | Link to thisI should clarify; No giant space paintball gun research, unless, of course, I get to fly one of the proposed ships.
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