At www.physorg.com/print221392528.html there is a report from Spaceweather.com that said two small asteroids came close to earth on April 6th – half the distance of the Moon. They were 10km and 6km wide respectively – and there are more on the way later in the year.
Meanwhile, Apostolos Christou and David Asher of Armagh Observatory in Ulster announced the discovery of an asteroid that orbits the Sun in a horseshe trajectory. Such orbits are regarded as unstable but the astronomers have shown the orbit could have been a feature of near space for up to a million years – which sounds stable from a human perspective. See www.dailygalaxy.com April 7th (has also been featured this week at www.physorg.com and www.sciencedaily.com ). However, to get the story from the horse's mouth, so to speak, go to www.jpl.nasa.gov/news/cfm?release=2011-1128&cid=release_2011-112 where it was the WISE mission that picked up the unusual horseshoe orbit. The origin of the asteroid is the next problem to solve and a NASA spokesperson says they are really excited that astronomers are using WISE data to unearth 'treasures' – a figure of speech. See also the Armagh version at www.arm.ac.uk/press.2011/aac_horseshoe_orbit.htm