::Interactive Astronomy::

Asteroids

Asteroids are objects which orbit the sun. They are space objects that failed to combine into planets during the birth of our solar system. Certain asteroids like Ceres and Vesta are large enough to possess gravity strong enough to pull the itself into a sphere. The other smaller asteroids look like small fragments of distorted shapes.

Classification of asteroids:

C type. It makes up 75% of present asteroids. These asteroids have a low Albedo (reflectivity of light). The C represents “Carbonaceous”, which means high in carbon.
S type. It makes up 17% of present asteroids. These asteroids have a high Albedo. They are comprised of nickel-iron with iron and magnesium silicate in a metallic state.
M-type. It makes up most of the rest of the asteroids. They have a bright Albedo, close to the S types. They are comprised of pure nickel iron.
Other minor types for the rest of the remaining asteroids.

Asteroid Belt: This is where most asteroids are found to orbit. The Asteroid Belt is an orbit path around the sun whose territory is the whole area between the orbit of Mars and Jupiter. Asteroids often fly past Earth; a few have crashed into our planet before. The dinosaurs’ extinction is thought to be due to an asteroid’s impact with Earth. A good example is the crater in Northern Arizona.

The Asteroid Belt is the elliptical orbital plane of most asteroids. It is located between the orbits of Mars and Jupiter. The asteroids occasionally crash into one another in the Asteroid Belt and fragment into smaller pieces. It was formed due to the gravitational capturing of asteroids into this region by mainly the inner planets (Mercury, Venus, Earth, Mars) and Jupiter. Jupiter exerts a strong gravity which keeps most of the asteroids in this belt and as a result shielding the inner planets, including Earth, from repeated crashes from asteroids with instable orbits.

NEOS: Extraterrestrial objects that possess a threat to Earth are known as Near Earth objects (NEOS). Scientists are currently listing potential NEOS which may threaten Earth as the result of an impact would be disastrous to humans. None so far is listed as threatening.

Meteoroids, Meteors and Meteorites

These three terms are commonly misunderstood and misused by people. These are their correct definitions.

Meteoroids: Small objects orbiting the sun. They may be fragments of asteroids, comets or planets. Meteoroids orbit the sun in a large belt. A meteor shower could be seen when Earth passes through their orbit.

Meteors: A flash of light produced by a meteoroid when it enters the Earth’s atmosphere. A meteor is known as a Sporadic Meteor. Many meteors formed by many meteoroids are known as a Meteor Shower. An extremely bright meteor, brighter than Venus (the second brightest object besides the moon), is known as a Fireball.

Meteorite: An object from space that has landed on Earth’s surface.