impact
catdynamics | February 14, 2013A bolide hit the Earth over Russia, breaking up at low altitude, causing a strong shock that reached the ground causing damage.
There are reports of some fragments hitting the ground.
Good summary and videos at The Age
video from Russia Today
the fragments will be valuable and probably show up soon on ebay
there was no shootdown, the breakup is normal when the meteorite gets lower down into the atmosphere.
There are no issues with radiation [sic]
looks like a fairly slow shallow angle impact, detonating with kiloton++ energy below few km altitude - guessing from the video
that'd make it a…
esiegel | May 8, 2008Let's say we're having a nice day here on Earth; the Sun is shining, the clouds are sparse, and everything is just looking like a peach:
And then Lucas goes and tells me,
Oh my God, Ethan! It's Armageddon! An asteroid is coming straight for us! You've got to stop it!
Really? Me? Well, how would I do it? Let's say we've got some reasonably good asteroid tracking going on, and we've got about 2 months before the asteroid is actually going to hit us. We'd like to do something with the situation on the left, to avoid the situation on the right:
Well, what we really have to do is change the…
esiegel | April 30, 2008But I didn't want one! Stop your whining, Earthlings. We have a serious question to answer, courtesy of Tamara:
What’s the moon like below its surface, moving into the interior? And what’s the current thought on its formation?
Well, we do know a lot about the Moon's insides the same way we know about the Earth's; just like the Earth has earthquakes, the Moon has moonquakes. These tell us about the Moon's interior. From back when we landed on the Moon, we planted the Apollo seismic experiments and saw 28 moonquakes. From these, we learned that the Moon has a crust about 60 km deep, a deep…