Asteroids and comets have several things in common, including a relatively small size as compared to planets and a lack of a viable atmosphere. Asteroids range in size from a few feet to several miles in diameter. Comets are generally smaller, with a rocky core. Both comets and asteroids don't have enough gravity to keep atmospheres.Continue Reading
Scientists believe comets and asteroids are leftover fragments from when the solar system formed 4.5 billion years ago. Asteroids are closer to the sun, usually between the orbits of Mars and Jupiter in the asteroid belt. Comets mainly exist at the outer edge of the solar system.
Another commonality between asteroids and comets is the way the objects hurtle toward the inner solar system. Collisions with nearby objects and gravitational pulls from distant bodies push or pull asteroids and comets closer to the sun. Some of these objects get close enough to Earth to be seen with the naked eye. Both comets and asteroids pose a threat to life on Earth if they collide with the planet.
Asteroids are chunks of rock made of heavy minerals. Comets are mostly dust and ice crystals. When comets get close to the sun, particles are jettisoned behind these objects and produce a luminous tail. Asteroids don't glow when they get closer to the sun.Learn more about Comets & Asteroids
Most asteroids originate from a large area between the planets Mars and Jupiter. This area is most commonly referred to as the asteroid belt and contains more than 200 large asteroids. Some asteroids may originate from other regions in space.Full Answer >
Most meteors that enter the Earth's atmosphere are pieces of asteroids from the asteroid belt. The meteors were formed more than 4 billion years ago during what is thought to be the early stages of the solar system.Full Answer >
Although NASA hasn't calculated an average, asteroids range in size from Ceres, measuring 590 miles in diameter, to smaller ones that measure less than a half-mile across. The last near-Earth asteroid count was performed in 2013. NASA found 861 asteroids measuring more than 0.6 miles across.Full Answer >
Some facts about the solar system to teach children in elementary school are that it is found in the Milky Way galaxy, is approximately 4.6 billion years old and consists of the sun and different celestial objects, such as planets, moons, asteroids and comets. Although the solar system originally was made up of nine planets, now scientists consider that there are only eight planets. In 2006, the planet Pluto was demoted to dwarf planet status.Full Answer >