2012 DA14 was discovered on 2012, Feb. 23 by La Sagra Sky Survey in Spain using a 0.45-m f/2.8 telescope, and the discovery was issued on MPEC 2012-D51. Soon it was clear that it would have passed very close to Earth almost exactly one year after the discovery, and so it was.
On 2013, Feb. 15 around 19.30 UT it reached perigee at a distance of about 27.700 km from the surface of the Earth (0.09 LD), well inside the belt of geosyncronous satellites but with no risk of collisions given its orbit.
The asteroid has an estimated diameter of about 40 meters, and it is currently the biggest asteroid passed so close to the Earth: other objects passed closer, but they were smaller.
Despite some clouds interfered with the observations, we were able to catch it at 21.21 UT, when it was in constellation Ursa Major (the Big Dipper) at a distance of 59,000 km and moving at 1084″/min in PA around 6.0°.
The 60-sec image, visible below, was taken with a Pentax 75mm refractor f/6.7 and a CCD SBIG ST8-XME (FOV approx 90′ x 60′). The beginning of the trail (bottom) has the following coordinates: RA 12h 31m 25s – DEC +52° 16′ 50″.
After one hour I also imaged it with a 0.38-m f/6.8 reflector and the same CCD, giving a FOV of (only) 18′ x 12′. The asteroid had half the speed of the previous image (576″/min).
Here the beginning of the trail (bottom) has the following coordinates: RA 12h 44m 31s – DEC +67° 11′ 26″.
During the close approach 2012 DA14 was observed with the 70-m DSN antenna at Goldstone; the result was this interesting movie: