On July 4, 2005, NASA’s Deep Impact mission smacked an 800-pound block of copper into a comet.
That’s pretty cool all by itself. But the science behind the mission was to find out what happens when a comet is hit, what materials a comet is made of, and what materials lie beneath the surface. I wrote a series of posts about the mission (here, here, and here) back when it happened.
I also flew down to LA to do an interview for a British TV show called Star Date. The interviewer was rock star/physicist Brian Cox, and we had a smashing (har har) time talking about how Hollywood portrays asteroid and comet impacts. We sat on the roof of a hotel and chatted about the movie "Deep Impact". After much woe (converting VHS tapes! Converting VOB files! Uploading! Downloading! Fire! Destruction! And I still couldn’t get the frackin’ aspect ratio right), I was finally able to put the interview up on YouTube.
This was just a bit of fun, but it was excellent meeting Brian. I hope to do more with him in the future; I can see we have very similar vision on how science should be presented to the public.
October 15th, 2007 at 9:21 pm
Thank you! Thank you so much! Once again, this blog is the high point of a bad day.
October 15th, 2007 at 9:27 pm
“…as one science fiction author likes to say…”
That’ll be Larry Niven, my fave, along with David Brin. ‘Hard’ SF is the only way to go, IMHO..
–Jeff
October 15th, 2007 at 9:46 pm
Speaking of Deep Impact (the mission, not the movie), I’m reminded of this passage from the novel, 2001: A Space Odyssey:
“The probe carried no instruments; none could survive a collision at such cosmic speeds.It was merely a small slug of metal, shot out from Discovery on a course which would intersect that of the asteroid.
“As the seconds before impact ticked away, Poole and Bowman waited with mounting tension. The experiment, simple though it was in principle, taxed the accuracy of their equipment to the limits. They were aiming at a hundred-foot-diameter target, from a distance of thousands of miles.
“Against the darkened portion of the asteroid there was a sudden, dazzling explosion of light. The tiny slug had impacted at meteoric speed; in a fraction of a second all its energy had been transformed into heat. A puff of incandescent gas had erupted briefly into space; aboard Discovery, the cameras were recording the rapidly fading spectral lines. Back on Earth, experts would analyze them, looking for the telltale signatures of glowing atoms. And so, for the first time, the composition of an asteroid’s crust would be determined.”
October 15th, 2007 at 10:24 pm
An interesting way to perhaps deflect (but not destroy) a moving asteroid or comet on a collision course with Earth is with a kind of net. Note: The netting is not designed to snag an asteroid like a butterfly as intuition might imply. It is inspired by the stretchable chain link fences on some mountainous highways around the world, which stop tumbling downhill boulders from hitting a roadway by slowing them down. The mountain fences eventually stop the boulders (if they aren’t too big.) On the other hand, the space-going nets are designed to only slow the asteroid and thus alter its trajectory.
A rocket deploys a space craft on a rendezvous course which in turn is designed solely to deploy a very large spun carbon-fiber cable net, (sort of like a huge incredibly strong but stretchable fishing net). The secret of the net is its stretching ability which applies a broad force against the asteroid over the timeframe of a collision.
The net, moving rapidly through space toward the asteroid or comet, literally collides with and then envelops it. Though the asteroid/comet continues on its way, the total mass of the giant net rapidly exerts a counterforce over a large surface area of the asteroid rather than a point on its surface. This wide nudge, applied to a large surface area eventually alters its course so that it arrives (for example) a half hour too late to impact the Earth.
October 16th, 2007 at 1:13 am
I went to a Science Week lecture by Brian Cox when he was in Australia last year, and I wrote in my blog about how impressed I was with his manner in the face of the inevitable weirdos in the audience.
And just what is it with these former pop stars and physics PhDs?
October 16th, 2007 at 2:39 am
Ah, that reminds me, are you planning on reviewing (or just sharing your thoughts on) Sunshine?
October 16th, 2007 at 3:01 am
My kids and I met Brian Cox on a Physics talk at Birmingham University just a couple of weeks ago. He’s a real gent. A brilliant outreach advocate. He shows you aerial photos of particle accelerators and claims they are all built near airfields “to give you an idea of scale”. Great man.
October 16th, 2007 at 3:14 am
I know this is way off-topic, but I came across this link over at PZ’s place, and I thought it would be interesting to share yet another instance of paredola sp?) with the good BA & group.
http://www.dailymail.co.uk/pages/live/articles/news/worldnews.html?in_article_id=487764&in_page_id=1811
It seems that JPII is now appearing in bonfires….
October 16th, 2007 at 3:29 am
Brian Cox is the Vince Noir of science.
October 16th, 2007 at 7:47 am
He’s also one of my heroes. He’s on the Guardian science podcast quite often.
October 16th, 2007 at 3:09 pm
Why Copper? Couldn’t they have used a less expensive metal? The price of Copper is one of the reasons the house we are building now is more than it should be. People are dieing stealing Copper out of abandoned buildings (because they cut a live wire and become a Darwin Award winner). Just curios why they used Cu.
October 16th, 2007 at 3:55 pm
Now THATS an interview with a SOMEONE!!!
October 16th, 2007 at 3:58 pm
Maybe I got you wrong, but: you really want to watch the end of the world through a telescope? I bet watching the comet in outer space will be quite incredible, but when it hits the planet, I guess I will have better things to do (maybe say “Good Bye” to my family or to my friends). But everyone must die the way he wants to - and, well, yes. Maybe it is the way you think you can “leave the world”: Holding Mrs BA and the LittleBA in your arms while you look through the ’skope! Thats the way the BA will end
.
October 16th, 2007 at 4:08 pm
Copper was used principally on the presumption that there’s little copper, if any, in a cometary crust. The material in the impactor would be vaporised to incandescence along with a large amount of the crust. The chemical composition of the crust, measured by the emission spectrum of the collision, needs to be cleanly distinguishable from that of the impactor. By using a material not in the crust, it can be subtracted later from the spectrum.
Of course, if it had turned out the comet was nothing but a huge Lincoln penny, all bets would’ve been off.
October 16th, 2007 at 4:26 pm
DrFlimmer: I think the BA was referring to watching NASA’s future preventative spacecraft explode or deflect the comet, (or my giant net get punctured with no effect on its collision course.)
October 17th, 2007 at 5:02 am
Dr. Cox is one of my *fave* science popularizers, up there with Dr. Sean Carroll, Dr. Carl Sagan, and the BA (of course ;))! I hope he starts getting a lot more air-time and press over here. His wife Gia is cool too and writes a most excellent blog.
October 17th, 2007 at 12:00 pm
Suggestion for hard science fiction story, dystopian type — steal the plot of Hemingway’s ‘Old Man and the Sea’ — protagonist goes out into the deep to try to capture one of these objects and divert it into a capture orbit, but it’s friable and every attempt to nudge it nibbles away at it instead, and they bring back some tiny little remainder. For the utterly black version, the fragments shotgun the planet.
Seriously, I want to see more attention to catch-and-release technology.
Surely someone’s come up with a device that drags a net or otherwise arranges to get caught up and carried along, grabs the comet or asteroid firmly enough that a few ion engine devices can tie themselves down, network themselves, orient themselves, and then start gently steering the asteroid into a path that (with any number of ’slingshots’ or other careful path selection) will eventually bring it back into a useful orbit, maybe a leading or trailing Lagrange point.
I’d invest in that. Big payback in a few decades.
October 17th, 2007 at 6:45 pm
Hank Roberts: “Surely someone’s come up with a device that drags a net or otherwise arranges to get caught up and carried along…”
Look earlier in this thread. I have a suspicion in terms of physics that a net won’t stop an asteroid barreling in at 100 MPS relative to Earth however the idea of a large net-like screen many miles across, (you could drive a bus between the openings,) that applied a uniformly strong counterforce via a collision with the comet or asteroid, by stretching and applying equal resistance over a large surface area might actually be a viable way fo quickly altering the trajectory.
October 21st, 2007 at 8:38 am
OMG, you mean the comet didn’t implode into a fusioning star upon impact?