Table of brightest asteroids for 2008 Close approaching asteroids
The Asteroids, also known as Minor Planets, are small "planets" orbiting the Sun, mostly between Mars and Jupiter. The largest, Ceres, has a diameter of about 933 km, most are much smaller. Over hundred thousand have had their orbits described, but only a few of the larger ones are bright enough to be picked up in binoculars. Mostly this will be only for a month or two either side of opposition, that is when the asteroid is on the opposite side of the Earth to the Sun. It is then at its closest to the Earth and is also fully lit by the Sun as seen from the Earth.
Details are given of the asteroids which reach an opposition magnitude 9.0 or brighter during 2008. At this magnitude an object should be visible in 50 mm aperture binoculars from a dark site, with clear skies and without too much Moon light.
For each asteroid a chart is included showing its path. The charts show stars to magnitude 9.5 and each has a circle on it representing a 5° field. This is a typical field for 8x50 or 10x50 binoculars. In addition there is a table showing the position (right ascension and declination) of the asteroid at 10 day intervals while it is at magnitude 9.5 or brighter.
Charts are for the southern hemisphere with south at the top and east to the right. Anyone using a chart in the northern hemisphere would need to turn it upside down. The charts would give a "true" view when the asteroid is due north. When to the east or west, the sky would appear to be rotated, clockwise if to the east and anticlockwise when to the west, as seen from the southern hemisphere.
The table below lists all asteroids which meet the criterion of magnitude at their opposition in 2008. The magnitude given is that at opposition, which is usually when the asteroid is at its brightest.
| Asteroid | Opposition date | Magnitude | Range of dates brighter than 9.5 |
|---|---|---|---|
| (15) Eunomia | 2008 January 10 | 8.2 | 2007 November 1 to 2008 February 28 |
| (6) Hebe | 2008 February 7 | 8.8 | 2008 January 7 to February 29 |
| (11) Parthenope | 2008 August 6 | 8.8 | 2008 July 13 to August 31 |
| (4) Vesta | 2008 October 30 | 6.5 | At all times |
| (9) Metis | 2008 November 4 | 8.5 | 2008 September 27 to December 18 |
| (2) Pallas | 2008 December 4 | 8.0 | 2008 July 19 to 2009 November |
| (1) Ceres | No opposition in 2008 | At all times | |
The name of the asteroid shows it was discovered late in 2007. A list of close asteroids on the Minor Planet Centre web site shows there have been two other close passes this month, both at about the distance of the Moon. These were on January 13 and 16. Both were discovered only about the time of their closest approach. Apart from these 2007 TU24 is the closest expected at present for 2008. More may be discovered nearer the time at which they are closest to the Earth.
The closest approach of an Asteroid predicted for future years is on 13 April 2029 (14 April in NZ), when (99942) Apophis will pass at about 35000km, one-tenth of the distance of the Moon. This may well be bright enough to be briefly visible by eye. Unfortunately for NZ its time of closest approach is estimated to be about 10 am.