(85989) 1999 JD6
(85989) 1999 JD6 (provisional designation 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.
| Discovery | |
|---|---|
| Discovered by | LONEOS |
| Discovery date | 12 May 1999 |
| Designations | |
Minor planet category |
|
| Orbital characteristics | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 9167 days (25.10 yr) |
| Aphelion | 1.44183 AU (215.695 Gm) |
| Perihelion | 0.32425 AU (48.507 Gm) |
Semi-major axis | 0.88304 AU (132.101 Gm) |
| Eccentricity | 0.63280 |
Orbital period (sidereal) | 0.83 yr (303.1 d) |
Mean anomaly | 137.83229° |
Mean motion | 1.18778°/day |
| Inclination | 17.05701° |
Longitude of ascending node | 130.21399° |
| 309.18377° | |
| Earth MOID | 0.0487023 AU (7.28576 Gm) |
| Jupiter MOID | 3.86909 AU (578.808 Gm) |
| Physical characteristics | |
| Dimensions | ~0.7 km × 2 km (contact binary) |
Synodic rotation period | 7.6638 h (0.31933 d) |
| ~0.15 | |
| K (SMASS) | |
| ~16–18 | |
| 17.1 | |
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.