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Discovery[1]
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|---|---|
| Discovered by | LINEAR (704) 1.0-m Reflector |
| Discovery date | 1998 May 27 |
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Designations
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| MPC designation | (152680) 1998 KJ9 |
| Minor planet category |
Apollo NEO, PHA[2] |
| Epoch 2011-Aug-27 (Uncertainty=0)[2] |
|
| Aphelion | 2.3743 AU (Q) |
| Perihelion | 0.52157 AU (q) |
| Semi-major axis | 1.4479 AU (a) |
| Eccentricity | 0.63978 |
| Orbital period | 1.74 yr |
| Mean anomaly | 181.06° (M) |
| Inclination | 10.932° |
| Longitude of ascending node | 98.712° |
| Argument of perihelion | 259.92° |
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Physical characteristics
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| Dimensions | ~500 meters[3] |
| Mass | 7.87×1010 kg[4] |
| Mean density | ? g/cm³ |
| Equatorial surface gravity | ? |
| Absolute magnitude (H) | 19.4[2] |
(152680) 1998 KJ9 is a near-Earth asteroid and potentially hazardous object.[2] It has a well determined orbit with an excellent observation arc of 21 years and an Uncertainty Parameter of 0.[2] It was discovered on 27 May 1998 by the Lincoln Near-Earth Asteroid Research (LINEAR) at an apparent magnitude of 17.6 using a 1.0-metre (39 in) reflector.[1]
Based on an absolute magnitude of 19.4,[2] the asteroid has an estimated diameter of about 500 metres (1,600 ft).[3] 1998 KJ9 is noted for a close approach to the Earth on 31 December 1914 at a distance of 0.00155 AU (232,000 km; 144,000 mi).[5] It is one the largest objects known to have come inside the orbit of the moon. During the 1914 close approach the asteroid reached about apparent magnitude 7.7.[6]
The asteroid will pass 0.006 AU (900,000 km; 560,000 mi) from dwarf planet Ceres on 24 July 2018.[7]
| Preceded by |
Large NEO Earth close approach (inside the orbit of the moon) 31 December 1914 |
Succeeded by 2002 JE9 |
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