Table of brightest asteroids for 2010 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.
For further details of asteroids visit the JPL small-body database browser.
| Asteroid | Opposition date | Magnitude | Range of dates brighter than 9.5 |
|---|---|---|---|
| (4) Vesta | 2010 Feb 18 | 6.1 | At all times |
| (532) Herculina | 2010 Mar 13 | 8.8 | Jan 25 to May 3 |
| (2) Pallas | 2010 Apr 30 | 8.7 | 2009 and up to 2010 Jul 10 |
| (1) Ceres | 2010 Jun 19 | 7.1 | At all times |
| (15) Eunomia | 2010 Jun 27 | 9.0 | June 1 to August 2 |
| (8) Flora | 2010 Sep 10 | 8.2 | July 19 to November 19 |
| (6) Hebe | 2010 Sep 19 | 7.7 | June 24 to 2011 Jan 2 |
| (7) Iris | 2011 Jan 24 | 8.7 | 2010 Oct 12 to 2011 Mar 21 |
The closest approach was on Mar 2, when an asteroid designated 2009 DD45 passed at a distance of 0.0004828 AU, that is just under 72 420 km, 19% of the Moon's mean distance. The next closest was on March 18, at a distance of .0005681AU, 85212 km.
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.
A 33 year list of predicted close approaches can be found at a Harvard IAU site. The information above was obtained from this site.