Comets, Asteroids and Meteors

Comets, asteroids and meteors have the same common denominator. They are fragments of the materials that created the Sun and the planets during the fusion about 5 billion years ago. They cannot be considered as planets because they are relatively small.


Comets are very old in age. They are mostly made of ice and dust and grow a tail when they approach the sun. There are two types of comet tails, the ion tail and the dust tail. When the nucleus of the comets which is the ice approaches the sun, the solar energy will heat the ice and evaporate it making the gas flies off. Oftentimes, this melting process will break the nucleus apart and tosses dust to it. The evaporated gas will form a mist around the nucleus called the coma. On the other hand, when the solar radiation pushed the dust particle away from the comet, a dust tail is formed. Comets with dust tails are more visible by naked eye than those with ion tails. Comets originate in Oort Cloud and Kuiper Belt. Those that are from the Oort Cloud have long orbital periods and are able to move in the Solar System from any directions. The short period comets hail from the Kuiper Belt.

Asteroids are also small rocky objects that can be found in the Asteroid Belt between Mars and Venus. The largest known asteroid is the Ceres. The asteroids have different characteristics. Some asteroids are made up of loose small particles and are very light. Other asteroids are metallic while others are made of solid rock. Many of the asteroids have odd shapes because they have undergone impacts and do not have gravity to pull themselves back into spheres. Asteroids can be seen only by the aid of binoculars and telescopes.


Meteors or the heavenly bodies commonly called shooting stars are the short, small white pieces that stream across the sky. They are the products of asteroids and other inter-planetary dust that collide and slam into the Earth’s atmosphere. Meteors enter the Earth regularly but most of them are burned up. Those that are able to land the Earth are called Meteorites. When the Earth passes the orbital path of a comet, a meteor shower happens. Fireball is the small rock that is enormously bright and colorful that trails across the sky. Oftentimes, fireballs are mistaken for comets. However, comets do not flash in the sky quickly. They are observable in the sky for many days.