Date:28 January 2008
Scientists at Nasa’s Jet Propulsion Laboratory (JPL) in Pasadena, California, have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 metres in size. Asteroid 2007 TU24 will pass within 1,4 lunar distances, or 538,000 kilometres, of Earth on 29 January 12:33 am Pacific time (3:33 am Eastern time).
With these first radar observations finished, we can guarantee that next week’s 1.4-lunar-distance approach is the closest until at least the end of the next century, said Steve Ostro, JPL astronomer and principal investigator for the project. “It is also the asteroid’s closest Earth approach for more than 2 000 years.”
Scientists at Nasa’s Near-Earth Object Program Office at JPL have determined that there is no possibility of an impact with Earth in the foreseeable future.
Asteroid 2007 TU24 was discovered by the Nasa-sponsored Catalina Sky Survey on 11 October 2007. The first radar detection of the asteroid was acquired on 23 January using the Goldstone 70-metre antenna. The Goldstone antenna is part of Nasa’s Deep Space Network Goldstone station in Southern California’s Mojave Desert. Goldstone’s 70-metre diameter antenna is capable of tracking a spacecraft travelling more than 16 billion kilometres from Earth. The surface of the 70-metre reflector must remain accurate within a fraction of the signal wavelength, meaning that the precision across the 3 850-square-metre surface is maintained within one centimetre.
Ostro and his team plan further radar observations of asteroid 2007 TU24 using the National Science Foundation’s Arecibo Observatory in Puerto Rico on 27-28 January and 1-4 February.
The asteroid will reach an approximate apparent magnitude 10.3 on 29-30 January before quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will be observable in dark and clear skies through amateur telescopes with apertures of at least 7.6 centimetres. An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky.
Nasa detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called “Spaceguard”, discovers, characterises and computes trajectories for these objects to determine if any could be potentially hazardous to our planet. The Arecibo Observatory is part of the National Astronomy and Ionosphere Centre, a national research centre operated by Cornell University, Ithaca, New York, for the National Science Foundation. JPL is a division of the California Institute of Technology in Pasadena.
For more information, visit http://neo.jpl.nasa.gov