Russians offer to track asteroid threat
By Egan Orion on Jun 30, 2008 7:36AM
Russian scientists think a space probe should plant a radio beacon on the asteroid Apophis to determine whether it's going to impact Earth, a conference report said Friday.
The report also conjectured that the Russian Phobos-Grunt spacecraft presently scheduled to be launched in 2009 could accomplish that mission with only slight payload changes, but that its launch would have to be delayed until 2012 to make a rendezvous with Apophis.
Asteroid 2004 MN4 or 99942 Apophis, midsized as asteroids go at 350 meters in diameter, is considered the greatest known threat to collide with Earth, the report said.
Astronomers estimate that there are about 1,000 larger asteroids 1 kilometre in diameter or larger that are in Apollo, or earth-crossing orbits. So far they have found about 700 of them and they hope to find the rest by 2010.
In Egyptian mythology Apophis, or Apep the Destroyer, is the god of evil and destruction imagined as a snake living in eternal darkness.
In 2029 its namesake asteroid will graze Earth's orbit at a mere 36,000 km (22,400 miles) from the planetary surface, closer than geostationary satellites. Earth's gravity or a collision with one or more orbiting satellites could alter the orbit of Apophis such that it might hit Earth on its next approach in 2036.*
The impact of such a large asteroid as Apophis would be hundreds or thousands of times more destructive than the Tunguska Event of exactly one hundred years ago on Monday.
That meteor impact, thought to be that of a small asteroid or cometary fragment about 10 to 30 meters in diameter, was seen thousands of miles away and heard for hundreds of miles.
The Tunguska blast incinerated and flattened approximately 830 square miles of Siberian forest as it released vast energies equivalent to about 1,000 Hiroshima atomic bombs.
Such an Apophis impact "could lead to an area equal to France turning into a desert," said Alexander Simonov, one of the authors of the Russian report, in an understatement of the level of global destruction that would be unleashed by a meteor strike of that magnitude.
So large an asteroid or cometary fragment impact would likely start conflagrations over thousands of square miles and blast millions of tonnes of soil and pulverized bedrock into Earth's atmosphere, with smoke and particulates possibly starting a years long "nuclear winter" scenario that might create abrupt climate change, leading to worldwide famines and pandemic social disorders and wars, and human deaths in the tens or even hundreds of millions... and might start another Ice Age.
The report said that even the largest of ground-based radio telescopes cannot discern the orbit of Apophis with the required precision, so one potential solution would be to plant a radio beacon on the asteroid that could permit radio astronomers to determine its orbit within an accuracy of "tens of meters," that would reveal whether Apophis will hit Earth.
"We propose the Phobos-Grunt spacecraft... as a platform for this mission," the report said.
Phobos-Grunt is a planned Russian sample return mission to the Martian moon Phobos. Designed starting in 2001, Phobos-Grunt is currently scheduled for launch in 2009.
If the spacecraft's mission is amended to rendezvous with Apophis, the report said its launch should be delayed to May 13, 2012, and the flight is expected to take 330 days.
*Scientists have said that Apophis won't approach Earth at an attitude that risks colliding with any satellites, but we don't believe them and suspect that they're just saying that in a government ordered public relations effort to avert potential fears among the populace.
See Also Asteroid's chances of hitting Earth increase