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.Know More
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
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 >
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 >
Asteroids are formed from the leftovers of the formation of our solar system from about 4.6 billion years ago. Early on, the birth of Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, causing the small objects that were there to collide with each other and fragment into the asteroids seen today.Full Answer >
Dozens of asteroids orbit throughout the galaxy, but the most famous are those that have impacted the Earth. Asteroids that do are best known by the major craters they leave behind. The Vredefort crater was created by an asteroid nearly two billion years ago in South Africa. The crater has a radius of 118 miles and is believed to be the largest asteroid crater.Full Answer >