As reinforced by Hollywood blockbusters, the threat of a comet or asteroid hitting our planet is a cause of much consternation. One way that humanity is addressing the threat is through the NASA's orbiting Wide-field Infrared Survey Explorer, or WISE. This solar system diagram depicts comets, asteroids, and planets, as detected through the new NEOWISE project to hunt for near-Earth objects in WISE data.
Black specks depict asteroids, heavily concentrated in our solar system's main asteroid belt, between Mars and Jupiter. Blue and yellow squares depict comets found by the NEOWISE mission.
The green and red dots are most worrisome: They depict near-Earth objects, thought to come within 124,000 miles (200,000 kilometers) of Earth.
On average, a 0.3-mile (0.5-kilometer) or larger asteroid impacts Earth every hundred thousand years, according to NASA, and such impacts are thought to have caused mass extinctions.
Fortunately, smaller asteroids or comets tend to burn up in our atmosphere.
(Watch Naked Science: Preventing Armageddon on the National Geographic Channel, airing at 10 a.m. ET on Sunday, October 9.)