Following hot on the heels of the discovery of 2008 TM9 from Celbridge observatory.  Another asteroid has been discovered by an irish amateur astronomer.   On October 21st an asteroid was discovered by Dave Grennan at Raheny observatory.  This asteroid has been designated 2008 US3 by the International Astronomical Union.

Discovery images of 2008 US3 (Image: Dave Grennan)

Up until recently Ireland has had a rather poor run on discovering asteroids.  In 1848 Andrew Graham discovered the ninth ever asteroid from Markree Observatory, Co.Sligo.  160 years passed until the next asteroid was discovered.  This happened on October 8th, 2008 when Dave Mc Donald of Celbridge observatory (J65) discovered a brand new asteroid which was designated 2008 TM9.

Well the poor run of asteroid discoveries has now well and truly been laid to rest following the announcement of the discovery of asteroid 2008 US3 by Dave Grennan of Raheny Observatory (J41). 2008 US3 was discovered on October 21st. Confirmation of the discovery and the temporary name 2008 US3 was receivedfrom the Minor Planet Centre of the International Astronomical Union on October 24th.

2008 US3 (Marked in image above) is a main belt asteroid.  This means it orbits between the planets Mars and Jupiter where most of the asteroids reside.  It has a diameter between 3 and 6 kilometres.  Despite its large size, don't be expexting to see this asteroid in your telescope anytime soon. It's currently over 250million kilometres from Earth and it doesn't get any closer to us than that.  It was discovered at magnitude 19 which makes it about 400,000 times fainter than the fainest object that can be seen with the naked eye.  Only large telescopes and sensitive cameras can show objects this faint.

More information (including orbital elements) are available from NASA's 'Solar System Dynamics (SSD) page.

The initial vailsala orbit for 2008 US3 was announced on MPEC 2008-U66.

The latest orbit (3rd November, 12 day arc) is published on MPEC 2008-V04

More information will be posted here when available.

Update: 4th November 2008 - 2008 US3 Passes through M33 between November 9th and November 14th.

What am amazing event!!  However there is a downside.  During this period theMoon is almost full.  On November 12th the full Moon is just 17degrees from M33 making it next to impossible to image a magnitude 19.7 asteroid.  Still this wont stop me from trying to image this once in a lifetime event.  To have an asteroid pass through one of the brighter Messier objects is very rare and to have one that you discovered making should be far rarer still, but not our asteroid!!  The exact same occurance happens again almost four years later almost to the day! on November 11th 2012, then on November 9th 2016, and 9th November 2020 and 7th November 2024.