Most of the comets that enter the solar system originate in either the Oort Cloud or the Kuiper Belt, zones containing trillions of icy and rocky bodies orbiting in the furthest reaches of the sun's influence. Gravitational perturbations or collisions occasionally cause these comets to approach Earth.
The Oort Cloud is a large spherical cloud surrounding the solar system, and it is the source of most long-period comets that take more than 200 years to make a full orbit. The Kuiper Belt is a disc-shaped area of space beyond Neptune where most short-period comets originate. Both zones are believed to be remnants from the creation of the solar system around 4.6 billion years ago.Learn More
Comets are made up of collections of ice, dust and rocky particles that are leftover from the formation of the solar system 4.6 billion years ago. Comets range in length from a few kilometers to tens of kilometers. The nuclei are comprised of frozen gases such as carbon dioxide, carbon monoxide, methane and ammonia.Full Answer >
The majority of asteroids that scientists have formally identified reside between the orbits of Mars and Jupiter. Scientists call this wide swath of space the asteroid belt, and though it contains millions of objects, the combined size of all of the asteroids in the belt is smaller than the Earth’s moon.Full Answer >
The term "doomsday asteroid" is usually applied to an asteroid that, if it impacted Earth, would cause sufficient destruction to significantly disrupt the balance of life and possibly cause major extinctions. Such an asteroid would have to have an orbit that intersects the path of the Earth.Full Answer >
Meteors falling through the atmosphere, called shooting stars, occur regularly and are seen on any clear night every 10 to 15 minutes. Shooting stars occur reliably and in large numbers during the meteor showers that occur yearly based on the passage of particular comets or minor planets close to Earth.Full Answer >