Asteroid 2012 DA14, as previously discussed, passed record-close to Earth last month. On the same day a more news-grabbing, but smaller asteroid, the Chelyabinsk Meteroid, plunged into Earth’s atmosphere and streaked and exploded over Russia.
2012 DA14 was captured in numerous telescope and radar images. The following image shows the relative velocity of the asteroid as it is seen from the Canary Islands passing and moving away:
And the following is a radar image of the DA14 asteroid as it tumbles in its path past Earth, giving an interesting hint as to its shape and motion:
About half the size of a soccer field, the asteroid was discovered in 2012, and astronomers had plenty of time to prepare for its approach in order to watch and study as it passed.
The Chelyabinsk Meteroid, on the other hand, although another Earth-orbit cross asteroid, was about one tenth the size of 2012 DA14, made its final approach from the sun side, and was not discovered until its spectacular demise in Earth’s atmosphere February 15, 2013.
The image here illustrates the comparative size of the two asteroids with a helpful backdrop. The larger version of this image can be found at the B612 Foundation’s site, and is by talented illustrator Michael Carroll.
There are much larger Near Earth Objects. Many (and hopefully most or all) are known and being tracked. As to these recent visitors, the larger of the two–2012 DA14–might be big enough to mine for resources or convert into a small habitat. The smaller, while it still existed, would have been tight. But most asteroid-mining plans and habitat-conversion ideas focus on much larger bodies.