Mistaken near-miss asteroid alert defended

Astronomers defend a U.S.-run system intended to warn of pending asteroid impacts after it mistook a European Space Agency's spacecraft for an incoming rock.

The system interpreted the Rosetta spacecraft as an incoming rock last week and issued an alert that a near-miss was looming, New Scientist reported Monday.

Three U.S. observatories spotted an unidentified object heading Earth's way. The observation prompted the Minor Planet Center at the Harvard Smithsonian Center for Astrophysics in Cambridge, Mass., which coordinates the search of near-Earth objects, to issue a potential near-miss warning.

The warning was retracted after astronomer Denis Denisenko in Moscow noticed the object's trajectory closely matched Rosetta's, New Scientist said.

The incident raised questions about how well the warning system works. The Minor Planet Center said, "this incident highlights the deplorable state of availability of positional information on distant artificial objects."

Others countered that the Rosetta approach proved the system was robust.

"It shows that the telescopes are picking these objects up," says Robert Massey, a spokesman for Royal Astronomical Society in Britain.

While conceding a lack of coordination may have contributed to the error, Massey said he thought the fly-by was a good test of the alerting system.

Copyright 2007 by United Press International