Near-Earth asteroid: Difference between revisions
Frequency estimates added |
No edit summary |
||
| Line 12: | Line 12: | ||
'''Example''' |
'''Example''' |
||
On 2002 Jun 6 an object with an estimated diameter of 10 meters collided with Earth. The collision occurred over the Mediteranean Ocean. The energy released was comparible to a small atomic bomb. At that time India and Pakistan were at a heightened state of alert, ready to iniate a nuclear weapon war with each other. If this asteroid impact had hit in this area the results might have been catastrophic. |
On 2002 Jun 6 an object with an estimated diameter of 10 meters collided with Earth. The collision occurred over the Mediteranean Ocean. The energy released was comparible to a small atomic bomb. At that time India and Pakistan were at a heightened state of alert, ready to iniate a nuclear weapon war with each other. If this asteroid impact had hit in this area the results might have been catastrophic. |
||
'''Frequency''' |
'''Frequency''' |
||
Asteroids with a 1 kilometer diameter hit the Earth a few times in each million year interval. Large collisions with 5 kilometer objects happen every ten million years. Small collisions (but still potentially dangerous ones) occur a couple times each month. |
|||
Revision as of 21:28, 4 October 2002
Near-Earth asteroids are asteroids whose orbit intersects Earth's orbit and which may therefore pose a collision danger, as well as being most easily accessible for spacecraft from Earth. In fact, some near-Earth asteroids can be reached with much less ΔV than the Moon. The most famous near-Earth asteroid is 433 Eros that was visited by NASA's Near Earth Asteroid Rendezvous probe.
Asteroid orbit classification
"Near-Earth asteroid" is a more restrictive term than "near-Earth object."
External Link
JPL Near Earth Asteroid Tracking program (NEAT)
Example
On 2002 Jun 6 an object with an estimated diameter of 10 meters collided with Earth. The collision occurred over the Mediteranean Ocean. The energy released was comparible to a small atomic bomb. At that time India and Pakistan were at a heightened state of alert, ready to iniate a nuclear weapon war with each other. If this asteroid impact had hit in this area the results might have been catastrophic.
Frequency
Asteroids with a 1 kilometer diameter hit the Earth a few times in each million year interval. Large collisions with 5 kilometer objects happen every ten million years. Small collisions (but still potentially dangerous ones) occur a couple times each month.