Very close encounters

Asteroid 2011 CQ1 was discovered by the Catalina Sky Survey on February 4 and made a record close Earth approach 14 hours later on February 4 at 19:39 UT. It passed to within 0.85 Earth radii (only 5480 km !) of the Earth's surface over a region in the mid-Pacific. This object, only about one meter in diameter, is the closest non-impacting object in our asteroid catalog to date !

Prior to the Earth close approach, this object was in a so-called Apollo-class orbit that was mostly outside the Earth's orbit. Following the close approach, the Earth's gravitational attraction modified the object's orbit to an Aten-class orbit where the asteroid spends almost all of its time inside the Earth's orbit.