NASA's near Earth Object Program says the odds that a 400-meter asteroid, named 2004 MN4, will crash into Earth in 2029 is 1-in-60. An asteroid of this size hits our planet every ten thousand years or so. The asteroid rates a 4 on the ten-point Torino Scale.
Torino scale 4: "A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of regional devastation. Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away."
It's likely the odds will increase in our favor over time, but according to Mosnews, Viktor Shor of the Practical Astronomy Institute of the Russian Academy of Sciences says "his research predicts that the asteroid's orbit could change and it may return in seven years [following the first near miss in 2028 or 2029], this time crashing into the Earth's surface."
According to the model, the impact of a 500-meter asteroid traveling at a speed of 10-20 kilometers per second hitting the ocean would cause a circular wave 200-meters high. An asteroid 10 kilometers in diameter would cause a tsunami 4 kilometers high which would be about 400 meters high as it hit land. The scientists say that a similar disaster took place millions of years ago and resulted in the extinction of 90 percent of all living species.
By way of comparison, the asteroid that exploded over Siberia in 1908 was only 50 meters across. The blast was equivalent to 800 Hiroshima atom bombs and completely wiped out a half a million acres of forest. The asteroid (or comet) that wiped out the dinosaurs 65 million years ago was 10-kilometers in diameter.
Reader comment: douglips says:
"The information on 2004 MN4 you gave is out of date – there was a subsequent news release dated February 3 which ruled out impact in 2029. However, there is still a possibility of impact in 2036, a little more than 1 in 1000.
"Also, note that this asteroid has been renamed Apophis, which I'm sure will satisfy Stargate SG-1 fans everywhere.
"CURRENT risk profile for Apophis, should be updated by NASA occasionally: http://neo.jpl.nasa.gov/risk/a99942.html
"Wikipedia article: http://en.wikipedia.org/wiki/2004_MN4
"More recent news release than the December 2004 one previously cited on Boing Boing: http://neo.jpl.nasa.gov/news/news149.html"