In an example of something going from the pages of science fiction to the pages of history books, the Double Asteroid Redirection Test had a successful impact on the asteroid Dimorphos. In this video, I talk about what DART did, why it matters and what the future of space defense might look like.
Michael Siegel
Michael Siegel is an astronomer living in Pennsylvania. He blogs at his own site, and has written a novel.
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Another asteroid concept that seems to be gaining greater awareness is rubble-pile structure: asteroids that aren’t big single chunks of rock, but are a collection of small chunks held loosely together by gravity. That suggests the question of “What will the result of DART be if Dimorphos is a rubble pile?” My (uninformed) intuition would be that there are at least some possibilities where the kinetic energy of an impactor produces results that make no change to the trajectory of the pile as a whole, eg deformation of the overall shape or rotation. What do we try next if we didn’t nudge Dimorphos’s trajectory?Report
Wouldn’t that make Dimorphos about a jillion times more likely to be eaten by the atmosphere on the way down?Report
I don’t know. I don’t understand rubble-pile physics. My guess would be that a sizeable pile impacting at 20 km/sec straight down would behave much like a solid object of similar size and density, but it’s just a guess.
That’s with the pile as an impactor. Related to the OP, I’m interested in the pile as impactee.Report
Related, and I’m not sure if this has been posted elsewhere on this site (and others may have seen already it via twitter or other means)
Google “Nasa DART Mission” (quotes aren’t necessary and I don’t think capitalization matters either)
and wait a sec.Report