Asteroid Toutatis radar images.
This last week saw a flurry of asteroid watch action as several rocky bodies passed close to the Earth. Well, relatively speaking. On December 11, not one but THREE asteroids made scientists take notice.
Zip! There it goes! 2012 XE54 is spotted.
First on the list was 2012 XE54, a small bodied rock about 36 meters in size, passed within the Earth-Moon distance, a little over 60% of the distance. Not Earth-shattering, but big enough to possibly cause a Tunguska-like event if it had hit us. Scary note here: this was a recently-discovered asteroid, which shows you that there are dangerous steroids out there that we DON'T know about yet.
Next up was 2012 XL55, about half the size of XE54, but it wasn't as close... just a mere 4.2 times the distance from Earth to Moon (which itself is 240,000+ miles away). And on it's heels was 2009 BS5, just a little bit smaller, but twice as far away.
Then came the big show on the 12th. Asteroid 4179 Toutatis is an old friend, first discovered in 1934. It has a somewhat erratic orbit that actually crosses the orbit of Mars as well as Earth's, and is influenced by the gravity of Jupiter. It comes closer to earth about every four years. Radar images show it to be like a peanut shell in shape, with two lobes. It's greatest length is about 4.2 kilometers, making rather large actually. On December 13th, a Chinese space probe made a close pass to Toutatis. You can find all about that encounter here on SpaceRef: http://spaceref.com/asteroids/chinas-change-2-does-close-flyby-of-asteroid-toutatis.html
Toutatis came by at about 18 Lunar Distances. It is expected to make a really close pass in 2069!