| Discovered by LONEOS Observation arc 9167 days (25.10 yr) Inclination 17.05701° Mean anomaly 137.83229° | Discovery date 12 May 1999 Discovered 12 May 1999 Argument of perihelion 309.18377° Asteroid group Aten asteroid | |
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| Minor planet category Aten asteroid,near-Earth asteroid,potentially hazardous object Aphelion 1.44183 AU (215.695 Gm) Semi-major axis 0.88304 AU (132.101 Gm) Discoverer Lowell Observatory Near-Earth-Object Search Similar (33342) 1998 WT24, Kepler‑440b, WISE J22460757‑0526350, 1566 Icarus, 22P/Kopff | ||
(85989) 1999 JD6 is an Aten asteroid, near-Earth object, and potentially hazardous object in the inner Solar System that makes frequent close approaches to Earth and Venus. On the Earth approach in 2015, it was observed by the Goldstone Solar System Radar and found to be a contact binary with the largest axis approximately 2 kilometers wide, and each lobe about 200–300 meters large. Although 1999 JD6 in its current orbit never passes closer than 0.047 AU to Earth, it is listed as a potentially hazardous object because it is large and might pose a threat in the future.
The asteroid is well-observed, having been observed over 2,000 times over a length of over 25 years, and was assigned a numeric designation in August 2004.
July 2015 Earth passage
On 24 July 2015 1999 JD6 came as close as 19 lunar distances to Earth. It was imaged by radar, and shown to be a contact binary, about 2 kilometers (1.2 miles) on its long axis.