Anybody know how old Bruce Willis will be in February 2040? That's when the asteroid that has the best chances for striking Earth (and they are VERY LOW) has a 1-in 625 chance of doing so. Called Asteroid 2011 AG5, this 460-foot wide space rock was discovered in January 2011 by the 60-inch telescope of Project Spacewatch located atop Mount Lemmon in Arizona.
The asteroid is only 1 of 2 that out of 8, 744 is listed as a "1" on the TORINO Impact Hazard Scale - kind of a green, yellow, red chart that has a scale of 0 to 10 with 0 being no threat and 10 being "look out".
Astronomers were able to get some observations of 2011 AG5 before its' orbit took it behind the Sun. We will not be able to get further observations and nail down the space rock's orbit - and the exact nature of the very low threat to Earth - until 2013. The head of NASA's Near Earth Object Program feels that the odds will increase in Earth's favor that we will be safe from an impact.
IF this rock were to hit it would carry an energy of about 100 million tons of TNT - a large amount of energy to be deposited in one place, that is for sure. Such an impact would cause regional devastation but it would not be anywhere near the size that would cause an extinction event like that of the dinosaurs 65 million years ago.
2011 AG5 has caused the international astronomical community to once again address the threat that asteroids pose to our species. While experts think there would be enough time to mount a defense against 2011 AG5 if necessary, this event underscores the reason why we need a robust space program.
The threats from an asteroid or cometary impact are REAL.....it is not a matter of IF this will happen but rather WHEN. We get hit every single day from about 100 tons of space debris from space rocks and comets. And we have had a multi-megaton air burst from an asteroid (probably) that occurred in June 1908 over remote Siberia http://science.nasa.gov/science-news/science-at-nasa/2008/30jun_tunguska/.
Being able to mount a planetary defense against asteroids and comets requires being able to get out into space far from Earth and intercept them so we can divert them. Plans on how to do this are being discussed now. We have landed on asteroids and impacted comets so we know how to get to the enemy. The question is how best to defeat them.
Read More About 2011 AG5 http://www.jpl.nasa.gov/news/news.cfm?release=2012-051
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