PS1 telescope establishes near-Earth asteroid discovery record

Scientists battle time and weather to confirm discoveries

University of Hawaiʻi at Mānoa
Louise H. Good, (808) 956-9403
Editor and Press Officer, Institute for Astronomy
Dr. Nick Kaiser, (808) 520-3680
Astronomer, Institute for Astronomy
Posted: Feb 24, 2011

Richard Wainscoat (left) and Marco Micheli study one of the near-Earth asteroids found on Jan. 29.
Richard Wainscoat (left) and Marco Micheli study one of the near-Earth asteroids found on Jan. 29.

The Pan-STARRS PS1 telescope on Haleakala, Maui, discovered 19 near-Earth asteroids, on the night of January 29, the most asteroids discovered by one telescope on a single night.

“This record number of discoveries shows that PS1 is the world’s most powerful telescope for this kind of study,” said Nick Kaiser, head of the Pan-STARRS project. “NASA and the U.S. Air Force Research Laboratory’s support of this project illustrates how seriously they are taking the threat from near-Earth asteroids.”

Pan-STARRS software engineer Larry Denneau spent the night of January 29 in his UH Mānoa office processing the PS1 data as it was transmitted from the telescope over the Internet. During the night and into the next afternoon, he and others came up with 30 possible new near-Earth asteroids.

Asteroids are discovered because they appear to move against the background of stars. To confirm asteroid discoveries, scientists must carefully re-observe them several times within 12-72 hours to define their orbits, otherwise they are likely to be “lost.”

Denneau and colleagues quickly sent their discoveries to the Minor Planet Center in Cambridge, Massachusetts, which collects and disseminates data about asteroids and comets, so that other astronomers can re-observe the objects.

“Usually there are several mainland observatories that would help us confirm our discoveries, but widespread snowstorms there closed down many of them, so we had to scramble to confirm many of the discoveries ourselves,” noted UH Mānoa Institute for Astronomy astronomer Richard Wainscoat.

Wainscoat, astronomer David Tholen, and graduate student Marco Micheli spent the next three nights searching for the asteroids using telescopes at Mauna Kea Observatories.

On the evening of January 30, they confirmed that two of the asteroids were near-Earth asteroids before snow on Mauna Kea forced the telescopes to close. Then, on Monday evening, they confirmed nine more before fog set in. On Tuesday evening, they searched for four, but found only one. After Tuesday, the remaining unconfirmed near-Earth asteroids had moved too far to be found again.

Telescopes in Arizona, Illinois, Italy, Japan, Kansas, New Mexico, and the United Kingdom, and the Faulkes Telescope on Haleakala also helped to confirm seven of the discoveries.

Two of the asteroids, it turns out, have orbits that come extremely close to Earth’s. There is no immediate danger, but a collision in the next century or so, while unlikely, cannot yet be ruled out. Astronomers will be paying close attention to these objects.

The Pan-STARRS Project is being led by the UH Mānoa Institute for Astronomy, and exploits the unique combination of superb observing sites and technical and scientific expertise available in Hawaiʻi. Funding for the development of the observing system has been provided by the United States Air Force Research Laboratory. The PS1 Surveys have been made possible through contributions by the Institute for Astronomy, the University of Hawaiʻi, the Pan-STARRS Project Office, the Max Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, the Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network, Incorporated, the National Central University of Taiwan, and the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate. Any opinions, findings, and conclusions or recommendations expressed in this article are those of the author(s), and do not necessarily reflect the views of the National Aeronautics and Space Administration.

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