Thisstory was updated at 4:55 p.m. ET.
Russia is considering a plan to launch aspacecraft capable of moving a huge asteroid in a bid to protect Earth from animpact, but the target space rock poses virtually no threat to our planet andmoving it could actually make matters worse, experts say.
Americanastronomer Paul Chodas, part of NASA?s Near-Earth Object (NEO) Program Office,said Wednesday that claims by a top Russian space official that the asteroid Apophiswould definitely crash into Earth around 2036 are inaccurate.
?That?s notright,? Chodas told SPACE.com. ?The probability of an impact is going down.?
AnatolyPerminov, chief of Russia?s Federal Space Agency, said today that his agencywill soon hold a special meeting to discuss a potential mission to Apophis,according to Russian wire reports. Perminov spoke on the Voice of Russia radioand said experts from the United States and other nations and space agencieswould be able to join the project once the details are set.
Perminovsaid he had heard of Apophis? threat to Earth from a scientist who hadcalculated that the asteroid was getting closer and would ?surely collide withEarth in the 2030s,? according to Russia?s RIA Novosti news service.
Apophis isactually expected to fly harmlessly by Earth on April 13, 2036 and come within18,300 miles (29,450 km) of the planet at its closest approach.
In October,Chodas and NEO office colleagues at NASA?s Jet Propulsion Laboratory in Pasadena, Calif., announced that the odds of Apophis slamming into Earth when it swings byhad dropped to a low, 1-in-250,000 chance. Those odds improved on earlierstudies that predicted a 1-in-45,000 chance of an impact.
Theasteroid?s second near pass by Earth comes in 2068, when it has a three-in-a-millionchance (or about 1-in-333,000) of endangering the planet.
Chodas toldSPACE.com that Apophis will remain a top impact risk for Earth over the longterm, say over the next million years. But sending a spacecraft tointentionally tweak the asteroid?s orbit in the short term, when it poseslittle risk, carries its own dangers.
?You havethe potential of increasing the impact probability with failures in themission,? Chodas said. ?You could make matters worse.?
Anexploratory mission to studyApophis, and perhaps return a sample, could be a vital resource for anyfuture deflection efforts, he added. Knowing the composition of an asteroidwould likely play a large part in deciding exactly how to attempt to deflectits course.
Perminovdid not mention the recent Apophis impact risk estimates or elaborate onexactly how a Russian spacecraft may try to move the asteroid, though he didsay nuclear weapons would not play a role.
"Nonuclear explosions [will be carried out], everything [will be done] on thebasis of the laws of physics," RIA Novosti quoted Perminov as saying. Paststudies have weighed using everything from nuclear weapons and spacecraft?sgravity to rocket engines, robotic swarms and old-fashioned paint to protectEarth from space rocks.
DonYeomans, head of NASA?s Near-Earth Object Program Office, told SPACE.com that Russia?s interest in tackling potentially threatening asteroids in general is a good sign.
?WhileApophis is almost certainly not a problem, I am encouraged that the Russianscience community is willing to study the various deflection options that wouldbe available in the event of a future Earth threatening encounter by anasteroid,? Yeomans said in an e-mail. ?We haven?t found one yet but it doesmake sense to study deflection options in advance.?
Apophis hasbeen a poster child of sorts for the risk near-Earth objects pose to life onour planet because of the back-and-forth over when it could strike.
?Its orbitnearly intersects the Earth?s orbit,? Chodas said.
At onetime, early projections gave Apophis an alarming 1-in-37 chance of crashinginto Earth, sparking public fears of an imminent disaster. That?s about a 2.7percent chance of an impact somewhere on Earth. Better observations of Apophissince then have allowed astronomers to refine their projections of itstrajectory and quell hysteria over its hazard to Earth.
Apophis isabout 900 feet (270 meters) long and larger than two football fields overall.The asteroid is massive enough to create significant devastation to a region ifit ever did strike Earth. But it is not large enough to create a globalcatastrophe, NASA scientists have said.
TrackingApophis has been challenging because of its orbit, which lies within the orbitof Earth with the space rock hard to spot at times. The asteroid is expected tocome back within observation range of Earth (about 9 million miles) in late 2012and early 2013.
?Theadditional optical and radar data taken then will almost certainly remove anypossibility of an Earth collision in April 2036,? Yeomans said. ?To my mind itwould make sense to wait until 2013, refine the orbit and in the very unlikelyevent that the impact probability increases, then begin planning possibledeflection options.?
Still,Russian space officials apparently consider Apophis a significant threat tolife on Earth despite the low odds of an impact.
"People'slives are at stake. We should pay several hundred million dollars and design asystem that would prevent a collision, rather than sit and wait for it tohappen and kill hundreds of thousands of people," Perminov said, accordingto RIA Novosti.
