This week I'll be talking about how we would deflect asteroids...using spray paint! Back in 2013, scientists thought we could deflect asteroids using white spray paint. Let's explore how this may or may not be a good idea:
First, let us talk about the Yarkovsky Effect. This is an extremely small effect that sunlight has on an asteroid's surface. In a sense, the asteroid is nudged by sunlight! How? The asteroid's light-colored surface absorbs the sunlight and re-emits that energy as heat, which pushes the asteroid at an angle. How do we know that this actually happens? The most precise measurement done yet was by the Arecibo Observatory in Puerto Rico in 2012 on the asteroid 1999 RQ36, where pictures of the asteroid were taken in time lapse to discover sunlight actually pushing it around! They were so accurate in their measurements that it's like measuring the distance between Los Angeles to New York City plus-minus two inches!
So, what's with the spray paint? Notice that I said light-colored asteroids previously. Most asteroids are considered dark-color due to iron, which would absorb the sunlight with no deflection. To deflect the majority of these dark-colored asteroids, scientists thought it would be best to spray-paint the side of the asteroid with a white coating. Unfortunately, this plan has since then been swept under the rug.
With the recent launch of OSIRIS-REx, the study of asteroids will prove more beneficial on how to deflect these near-Earth asteroids. Or we would need a lot Krylon...
Thank you for reading and tune in next week for some cool stuff about Ganymede, the largest moon in our Solar System!