BBC news on Asteroid 2008 TC3 and the astronomers that observed it before it "hit" the Earth

"Hit" is in quotes because it technically broke up in the atmosphere so the only parts that hit the Earth were tiny fragments that were eventually recovered later.

The article is located here and has two videos, but don't watch the top one because it's 15 seconds of commercials plus 3 more seconds watching the BBC logo before 16 seconds of video...that you get to see in the second video (2 minutes+ in length) anyway.

Since this asteroid actually hit the Earth there's quite a bit of information about it compared to if it had just grazed us and been observed as it flew by like most others do (and almost none of these make it into the press). Here's the Wikipedia article on the asteroid, with such goodies as the asteroid's trajectory:



and its path as it flew over Sudan:


What was especially exciting about this asteroid is that it provided an opportunity to not just measure the spectrum of the asteroid as it came down, but also to check later on by looking at the actual shards found later on to compare the two. And the more accurate we are with our spectral analysis the more we can know about asteroids before they pass by or hit us.

Finally, the asteroid itself was also quite interesting:

Dr Peter Jenniskens of the SETI Institute in California, teamed up with Dr Muawia Shaddad and 45 students of the University of Khartoum to search the Nubian Desert.

Fifteen meteorites were recovered over an area 29km-long along the calculated approach path of the asteroid.

According to Dr Jenniskens: "The recovered meteorites were unlike anything in our meteorite collections up to that point.

"The asteroid has been confirmed as a rare type called F-class, corresponding to dark ureilite achondrite meteorites with a texture and composition unlike any other ureilite meteorites found on earth before."

The spectrum gathered by the astronomers allowed them to establish the first direct link between an asteroid and the individual meteorites produced as it breaks up in our atmosphere.

Comparing the asteroid and meteorite data tells us that 2008 TC3 may have only spent a few million years existing in the inner Solar system before it hit our planet.