(4953) 1990 MU
_1990_MU.svg) Orbit of asteroid (4953) 1990 MU viewed from the north ecliptic pole at the epoch of 1 January 2010 | |
| Discovery[1] | |
|---|---|
| Discovered by | Robert H. McNaught |
| Discovery site | Siding Spring Obs |
| Discovery date | 23 June 1990 |
| Designations | |
| NEO · Apollo · PHA[1] | |
| Orbital characteristics[1] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 41.16 yr (15032 days) |
| Earliest precovery date | 21 July 1974 (Siding Spring Observatory) |
| Aphelion | 2.6874 AU (402.03 Gm) |
| Perihelion | 0.55508 AU (83.039 Gm) |
| 1.6212 AU (242.53 Gm) | |
| Eccentricity | 0.65762 |
| 2.06 yr (754.00 d) | |
Average orbital speed | .4774 deg/day |
| 197.22° | |
| 0.47746°/day | |
| Inclination | 24.388° |
| 77.737° | |
| 77.748° | |
| Earth MOID | 0.0256049 AU (3,830,440 km)[1] |
| Physical characteristics | |
| 2.8 km[2] | |
| 14.218 h | |
| 14.1[1] | |
(4953) 1990 MU is a large Earth-crossing asteroid (ECA) belonging to the Apollo group of near-Earth objects which also cross the orbits of Mars and Venus. At approximately 3 km in diameter,[3] it is one of the largest known ECAs.[4] It has been assigned a permanent number from the Minor Planet Center (4953) indicating that its orbit has been very well determined. With an observation arc of 45 years, the asteroid's trajectory and uncertainty regions are well known through to the year 2186.[1]
Description
[edit]1990 MU was first observed over three nights in 1990. By itself, this was not enough for the asteroid to be given a permanent number since the orbit could not be calculated accurately enough for the object to be subsequently recovered. However, the object was precovered by the Anglo-Australian Near-Earth Asteroid Survey on six photographic plates from the UK Schmidt Telescope dating back to 1974. This technique has more success with the Amor group of asteroids which do not cross the orbit of the Earth and consequently have long periods of opposition when they can be observed. In this respect the Apollo asteroid 1990 MU is somewhat unusual.