"Schweickart and other scientists urged NASA to place a data-tracking radio transponder on the asteroid's surface by 2014."
"A transponder would help nail down orbital alterations caused by a phenomenon called the Yarkovsky effect. This is produced when an asteroid absorbs energy from the sun and re-radiates it back into space as heat. With one side of the asteroid lit and the other in darkness, the imbalance in thermal radiation produces a tiny acceleration. A transponder would help scientists understand how the Yarkovsky effect is influencing the asteroid's orbit."
"NASA responded to the urging with a wait-and-see proposal. 'We conclude a space mission based solely on any perceived collision hazard is not warranted at this time,' wrote Mary L. Cleave, associate administrator for NASA's science mission directorate."
"The agency believes continued optical and radio telescope observations will rule out Apophis as a threat. If not, NASA would launch a mission to the asteroid by 2018. A radio transponder, placed either in orbit or on its surface, would determine the asteroid's position in 2029 down to a few hundred feet, according to NASA."
"If an impact seems probable, a rocket would be launched to deflect the asteroid. The design phase would have to be completed by 2020 in order to launch by 2024, NASA noted."
"A 1-ton gravitational tractor could sufficiently divert Apophis outside the keyhole by hovering next to it for about a month, Lu and Love said."
"As scientists ponder that proposal, time marches on toward 2029 and 2036. Beginning this year, astronomers will lose visual and radar contact with Apophis, and the asteroid will not become visible again until 2013."
"Astronomers watch the skies for threat of deadly impact"
Bruce Lieberman
Paramus Post
March 17 2006
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