View Full Version : Airburst Explained: NASA Addresses the Russian Meteor Explosion

2013-Feb-15, 11:40 PM
A small asteroid entered Earth’s atmosphere early Friday, February 15, 2013 over Chelyabinsk, Russia at about 9:20 am local Russian time. Initial estimates, according to Bill Cooke, lead for the Meteoroid Environments Office at NASA’s Marshall Space Flight Center, is that the asteroid was about 15 meters (50 feet) in diameter, with a weight of [...]

More... (http://www.universetoday.com/100025/airburst-explained-nasa-addresses-the-russian-meteor-explosion/)

Philippe Lemay
2013-Feb-16, 06:01 PM
I've been looking at those numbers.... 300 kilotons? Isn't that about the size of a typical nuclear warhead? Wikipedia tells me that the W87 thermonuclear device has a 300 Kiloton yield.

Was the ground damage mitigated because the explosion happened so high up in the sky?

2013-Feb-16, 06:44 PM
Those are possibly high estimates. I haven't seen an estimate of the altitude when it expoded. Some of the energy was converted to EMP = electromagnetic pulse by the explosion. We should be hearing about thousands of failed electronic devices, unless there is a cover up. Part of the energy was also converted to hot air, but there was enough energy to blow out many windows = the flying glass caused most of the injuries. Likely buildings are built sturdier at that location to support lots of snow on the roof tops. Neil

Philippe Lemay
2013-Feb-16, 07:03 PM
Broken windows and doors is one thing, at 300 K-tons I would imagine there would be buildings flattened. Unless the energy dispersed in a nuclear fireball is fundamentally different to how these sort of high-speed projectiles deteriorate (or rather, detonate).

2013-Feb-16, 07:18 PM
Here is a thing (http://meyerweb.com/eric/tools/gmap/hydesim.html) that overlays the effects of a blast of your choosing over a map anywhere in the world. A 500 KT blast falls completely off the overpressure scale at 48 km. They stop plotting it at the 9.26 km mark. The sound took about 2.5 minutes to reach the ground in one clip that also showed the blast. At 5 seconds per mile, that's about 150 seconds, or 320 miles/50 km. If it had released that energy in town, it would have been much different.

2013-Feb-16, 08:37 PM
Some of the energy was converted to EMP = electromagnetic pulse by the explosion.

Is that really so? I'm surprised ... What is the mechanism for that?

2013-Feb-16, 09:47 PM
Plasma? Compressed air turns into plasma, fast moving plasma creates electromagnetic energy. The meteor might also have been turned into some plasma.

2013-Feb-16, 11:04 PM
OK. That sounds plausible. So then I wonder how much energy would be converted to an EMP in that way ... and would it be enough to (permanently) disable equipment or just cause some transient faults....

2013-Feb-17, 09:26 PM
Potential missions to NEOs

Ed Lu on CNN today
Meet The Press

I wonder if something like this could bag a spaceberg in a foldable biconic aeroshell http://whatsnext.blogs.cnn.com/2013/01/31/the-origami-inspired-folding-kayak/?iref=obinsite

The UN takes a look:
www.space.com/19840-asteroid-impact-threat-united-nations.html http://forum.nasaspaceflight.com/index.php?topic=31118.315