Oct 10, 2013
There are more than 10,000 near-Earth objects  that have been identified so far — asteroids and comets of varying sizes that approach the Earth’s orbital distance to within about 28 million miles. Of the 10,000 discoveries, roughly 10% are larger than six-tenths of a mile in size — large enough to have disastrous global consequences should one impact the Earth.
This is one of them.
First discovered in February 1950, 1950 DA is a 1.1-kilometer-wide asteroid that was observed for 17 days and then disappeared from view. Then it was spotted again on Dec. 31, 2000 — literally on the eve of the 21st century. Coupled with radar observations made a few weeks later in March 2001 it was found that, along with a rather high rotation rate (2.1 hours), asteroid 1950 DA has a trajectory that will bring it very close to Earth on March 16, 2880. How close? Close enough that, within a specific 20-minute window, a collision can not be entirely ruled out.
The image above was made from radar observations by the Arecibo Observatory in Puerto Rico in March 2001, when 1950 DA passed within 4.8 million miles of Earth. Is this the mug shot of a future continent-killer?