It's the Footnote in NASA's Report that Worries Me--Just Another Asteroid Heading Our Way, eh? Ho Hum, Nothing to Worry about"?
By Kevin Stoda, Germany
In January 2010, I barely followed the scientific and popular discussions around the world concerning whether the Apophis Asteroid will hit the earth--either in 2029 or 2036. I scoffed at the Russian worries that the earth might be hit or even disturbed by the comet.
German newspapers raised images of a group of Russian Bruce Willis's having to fly out into space and destroy the incoming Apophis Asteroid.
"The future for Apophis on Friday, April 13 of 2029 includes an approach to Earth no closer than 29,470 km (18,300 miles, or 5.6 Earth radii from the center, or 4.6 Earth-radii from the surface) over the mid-Atlantic, appearing to the naked eye as a moderately bright point of light moving rapidly across the sky. Depending on its mechanical nature, it could experience shape or spin-state alteration due to tidal forces caused by Earth's gravity field. This is within the distance of Earth's geosynchronous satellites. However, because Apophis will pass interior to the positions of these satellites at closest approach, in a plane inclined at 40 degrees to the Earth's equator and passing outside the equatorial geosynchronous zone when crossing the equatorial plane, it does not threaten the satellites in that heavily populated region. Using criteria developed in this research, new measurements possible in 2013 (if not 2011) will likely confirm that in 2036 Apophis will quietly pass more than 49 million km (30.5 million miles; 0.32 AU) from Earth on Easter Sunday of that year (April 13)."
I later read several other online critiques:
"It's important to note that NASA didn't just pull these numbers out of a hat; the space agency has been tracking Apophis intently since its discovery, plotted its position and projected its location to a very high degree of precision. The more we watch Apophis, the more the world's scientists are convinced that the asteroid poses a very tiny risk to life on Earth. In fact, giving anything a 1-in-250,000 chance of happening is more of a courtesy than a "risk.' Granted, we're talking about a global catastrophe should Apophis hit, but would you ever bet on those kinds of odds?"
"Really, you can sleep easy now. Apophis has become a very (very) unlikely doomsday candidate."