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.
Scientists estimate that about 200 asteroids in the belt exceed 60 miles in diameter. By contrast, 750,000 asteroids of about three-fifths of a mile in diameter are thought to reside among the larger ones. One of the largest objects in the asteroid belt is classified as a dwarf planet. Named Ceres, this large asteroid is thought to represent about one-third of the total mass of the asteroid belt.
Many asteroids have moons that orbit them, although none are large enough to contain an atmosphere. As far as scientists can tell, asteroids are not capable of supporting life. Occasionally, the gravity of a large planet perturbs the orbit of an asteroid. This can cause an asteroid to crash into a planet or moon. Approximately 65 million years ago, an asteroid hit the earth with enough force to kill most of the life on the planet. Scientists scan the skies for such large meteors, hoping to spot them before they impact Earth.Learn More
According to Yury Zaitsev, at Space Daily, an asteroid has a speed of about 55,923 miles per hour on average. Potential asteroid impacts on Earth have become a concern in recent years, with scientists suggesting the monitoring of all space objects in close proximity to the Earth.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 >
Mankind has dreamed of mining asteroids ever since the 19th century sci-fi serial "Edison's Conquest of Mars," but it has only come within scientific reach very recently. Asteroids are rich in metals found only in scarce quantities on Earth. If scientists figure out a way to tow an asteroid into the orbit of the moon, they can effectively harvest millions of dollars worth of minerals from even relatively small asteroids.Full Answer >
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.Full Answer >