65 million years ago, an asteroid collided with Earth. Scientists believe it measured about 6 miles across. It sparked the mass extinction that annihilated the dinosaurs. Could a similar event occur in our lifetimes? NASA, the United Nations, and various private foundations are trying to find out.
Gathering Data and Making Predictions
NASA's Near-Earth Object (NEO) Program is trying to identify asteroids, comets, and other space objects that could potentially strike Earth. The project has collected extensive data on hundreds of space objects. NASA displays this data in a variety of graphs so that the public can understand the dangers posed by these space objects.
In November 2007, a near-Earth asteroid that could potentially hit the Earth in 2048 was discovered. It was named 2007 VK184 and entered into the NEO Program's catalog. Current predictions put the odds of an impact at 1 in 1,820, or about a 0.055% chance. On the Torino scale, which rates the hazard posed by NEOs, it ranks a 1 out of 10. This means that it presents "no unusual level of danger" and the chance of a collision is "extremely unlikely." However, if the asteroid were to actually strike the surface of the Earth, it would hit the ground with a blast equivalent to 40 megatons of TNT, which is 2,000 times larger than the explosion of the atomic bomb dropped on Nagasaki, Japan during World War II.
NASA isn't the only group working to identify impact risks. The non-profit B612 Foundation is planning to launch a space telescope in 2017 or 2018. Named "Sentinel," the telescope will orbit the sun and identify objects likely to hit our planet. The group behind the project also hopes to develop technologies to deflect killer asteroids before they can hit the Earth.
See for yourself: http://neo.jpl.nasa.gov/stats/
Watch the following video about a near-Earth asteroid named Apophis and then answer the questions below.
What could happen if Apophis strikes Earth? How can we stop it from hitting us?