Close Approach of Near-Earth Object, 2010 AL30

  CLOSE APPROACH OF NEAR-EARTH OBJECT, 2010 AL30

2010 AL30 was discovered on January 10 by a 1.0-m f/2.15 robotic search telescope known as LINEAR operated by M. Blythe, G. Spitz, R. Brungard, J. Paige, and P. Festler of the Lincoln Laboratory ETS, New Mexico.  It became clear the next day that the object measuring 10-15 meters across would make an especially close approach to the Earth on January 13 passing safely by at about one-third the distance of the Moon.

With these type of discoveries, it is important to follow up each object measuring its exact position so that an accurate orbit can be determined since it may be potentially hazardous either by colliding with the Earth shortly after it is discovered or when it returns at some time in the future.   Observing sessions were conducted on January 12 by the BAA’s Asteroids and Remote Planets observing section, by ‘UKAPP’ (see http://star.pst.qub.ac.uk/~ukapp/project.html ) and by Helston Community College using both of the Faulkes telescopes.  A total of 81 astrometric positions having a mean uncertainty of about 0.2 arcsec were reported to the Minor Planet Center on January 12, roughly half of all those used to refine its orbit at the time, thereby permitting astronomers based at the Jet Propulsion Laboratory to target radar observations of the rock (see for example:http://planetary.org/blog/article/00002304/
It turned out that this object was unusual insofar as its orbital period around the Sun of 1.00 year was almost the same as that of the Earth.  The question was therefore asked whether it could in fact have been man-made and not a natural body.  However calculating the orbit back in time showed that the last occasion it had been close to the Earth was in 1929, i.e. well before the start of the Space Age, and so it could not have been launched from the Earth. ).

Photometry carried out on the images has revealed the object to be relatively spherical in shape and to be spinning very rapidly, turning once every 8.71+/-0.01 minutes.  The following link (http://www.asu.cas.cz/~asteroid/2010al30.png ) shows the rotational lightcurve from calculations made by Richard Miles of the BAA and  Petr Pravec of Ondrejov Observatory, Czech Republic.
For more information see also:  http://www.scibuff.com/2010/01/13/2010-al30-latest-info-and-more-photos/

Richard Miles
Asteroids and Remote Planets Section
British Astronomical Association