54509 YORP
Radar image and 3D model of YORP | |
| Discovery | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab's ETS |
| Discovery date | 3 August 2000 |
| Designations | |
| (54509) YORP | |
Named after | YORP effect |
| 2000 PH5 | |
| Apollo NEO | |
| Orbital characteristics | |
| Epoch 21 November 2025 (JD 2461000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 1826 days (5.00 yr) |
| Aphelion | 1.23717 AU (185.078 Gm) |
| Perihelion | 0.77455 AU (115.871 Gm) |
| 1.00586 AU (150.475 Gm) | |
| Eccentricity | 0.22996 |
| 1.01 yr (368.47 d) | |
Average orbital speed | 29.31 km/s |
| 130.15693° | |
| 0° 58m 37.245s / day | |
| Inclination | 1.59946° |
| 278.18528° | |
| 278.99884° | |
| Earth MOID | 0.000495246 AU (74,087.7 km) |
| Jupiter MOID | 3.72092 AU (556.642 Gm) |
| TJupiter | 6.029 |
| Physical characteristics | |
| Dimensions | 150 × 128 × 93 m |
| 0.2029 h 12.174 min | |
| 173° | |
Pole ecliptic longitude | 180° |
Pole ecliptic latitude | −85° |
| 22.7 (JPL) | |
54509 YORP (provisional designation 2000 PH5) is an Earth co-orbital asteroid discovered on 3 August 2000 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team at Lincoln Laboratory Experimental Test Site in Socorro, New Mexico. Measurements of the rotation rate of this object provided the first observational evidence of the YORP effect, hence the name of the asteroid. The asteroid's rate of rotation is increasing at the rate of (2.0 ± 0.2) × 10−4 deg/day2 which between 2001 and 2005 caused the asteroid to rotate about 250° further than its spin rate in 2001 would have predicted. Simulations of the asteroid suggest that it may reach a rotation period of ~20 seconds near the end of its expected lifetime, which has a 75% probability of happening within the next 35 million years. The simulations also ruled out the possibility that close encounters with the Earth have been the cause of the increased spin rate.