(285263) 1998 QE2
, provisional designation, is a dark asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Amor group, approximately 3 kilometers in diameter. It was discovered on 19 August 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. Its sub-kilometer minor-planet moon was discovered by radar on 30 May 2013.
Classification and orbital characteristics
As an Amor asteroid, the orbit of is entirely beyond Earth's orbit. The asteroid orbits the Sun at a distance of 1.0–3.8 AU once every 3 years and 9 months. Its orbit has an eccentricity of 0.57 and an inclination of 13° with respect to the ecliptic. The Earth minimum orbit intersection distance with the orbit of the asteroid is, which translates into 13.4 lunar distances. As with many members of the Amor group, this asteroid has an aphelion beyond the orbit of Mars which also makes it a Mars-crosser.The sooty surface of suggested that it might have previously been a comet that experienced a close encounter with the Sun. However, the Tisserand parameter with respect to Jupiter does not make it obvious whether was ever a comet, since cometary TJ values are typically below 3.
Earth approach
On 31 May 2013, approached within of Earth at 20:59 UT. This was the closest approach the asteroid will make to Earth for at least the next two centuries. It is a very strong radar target for Goldstone from May 30 to June 9 and will be one for Arecibo from June 6 to June 12. At its closest approach the asteroid had an apparent magnitude of 11 and therefore required a small telescope to be seen.Integrating the orbital solution shows the asteroid passed from Earth on 8 June 1975 with an apparent magnitude of about 13.9. The next notable close approach will be 27 May 2221, when the asteroid will pass Earth at a distance of.