Following on from the recent Earth flyby of 2012 DA14, another near Earth object (NEO) asteroid will make a close pass by of our planet at the end of May. At its nearest, the asteroid known as Minor Planet 285263 or 1998 QE2 will come within 3.6 million miles (5.8 million km) or about 15 times the distance between the Earth and the Moon. This irregular shaped piece of space rock is believed to be about 2.7 kilometres (1.7 miles) long; if it were to hit the Earth it would cause catastrophic damage, but rest easy there is absolutely no chance of a collision.

The asteroid close approach is an exciting event for professional astronomers. They plan to use NASA's 70 metre Goldstone dish in California and the 305 m Arecibo Observatory in Puerto Rico to study the asteroid in some detail. Lance Benner of NASA's Jet Propulsion Laboratory (JPL) said, "It is tremendously exciting to see detailed images of this asteroid for the first time". He added that "whenever an asteroid approaches this closely, it provides an important scientific opportunity to study it in detail to understand its size, shape, rotation, surface features and what they can tell us about its origin."

It's not just professionals who are looking forward to this; although the asteroid won't be visible to the naked eye amateur astronomers with small/medium sized telescopes should be able to spot it. The best time to look is on or around May 31st, the date of closest flyby, when the asteroid will be at its brightest (magnitude ~10.6). However, it won't be bright; 1998 QE2 will still be of the order of 100x fainter than the faintest naked eye stars and beyond the limit of 7x50 or 10x50 binoculars unless used from a dark site. Nether the less, it should be possible to spot the asteroid with a small telescope of around 80mm (3.1-inch) aperture. A 150mm (6-inch) or 200mm (8-inch) scope will make the job much easier.

The chart below shoes the position of 1998 QE2 from May 31 08:00 UT to June 3 00:00 UT.

Finder Chart for Asteroid 285263 (1998 QE2) from May 31, 2013 to June 3, 2013 - pdf format

During this time period the asteroid moves in northeastward direction through the constellation of Libra. The movement will appear leisurely in comparison to 2012 DA14, which literally buzzed across the night sky. Once spotted, it should be relatively easy to follow 1998 QE2 as it slowly weaves its way past the fixed background stars. On May 31 at 08:00 UT it's expected to shine at magnitude 10.9 before peaking at magnitude 10.6 on June 1st and then decreasing slightly to magnitude 10.7 the following day. Please note that at it's brightest the asteroid is still about 25x fainter than the faintest stars shown on above chart.

From temperate northern hemisphere latitudes (e.g. New York 41N, London 51.5N or Madrid 40N) 1998 QE2 is visible low down towards the south just before midnight. Although Libra is a faint constellation, it's bordered to the east by bright distinct Scorpius. Due to its southerly declination around the time of closest approach, the asteroid is better placed for observers in the tropics and southern hemisphere latitudes where it will appear much higher in the sky.

This event provides a great rare opportunity to spot a NEO. The object is within the range of amateur instruments and it's a once in a lifetime event to spot this rock, after the flyby, 1998 QE2, won't pass again this close to the Earth for another two centuries.

1998 QE2 (Asteroid 285263) Data Table