Asteroids are airless, rock worlds that orbit the sun. They are also called minor planets. Most of these minor planets are collected in the major asteroid belt, which is a vast doughnut-shaped ring found between the orbits of Jupiter and Mars. This belt has more than 1,150 asteroids. Larger asteroids have been given the name planetoids. The above terms have been historically used to refer to any astronomical body orbiting the sun but do not have the disc shape of a planet. Asteroids do not have the features of an active comet. They were discovered to have volatile-based surfaces like those of comets. There are a great many space rocks, the greater part of them thought to be broken pieces of planetesimals, bodies within the solar system that never grew big enough to become planets. Asteroids are different from meteoroids and comets. In the case of comets, th
...ey are composed of one element while asteroids are composed of rock and mineral. The average temperature on the surface of a typical asteroid is approximately -100 degrees Fahrenheit. Asteroids vary in sizes. The largest asteroid is nine hundred and thirty-three kilometres in diameter. The smallest asteroid discovered has a diameter of twenty feet, (Rubincam & Parry 11).
Astronomers discovered that asteroids exists all over space but are abundantly found in the asteroid band/belt between planets Jupiter and Mars. Asteroids are concentrated in this asteroid band because of orbital resonance between Jupiter and asteroids. Asteroids whose orbital periods are simple ratio compared to Jupiter’s orbital period experience the same gravitational pull on regular basis. Astronomers believe that this belt is a primordial material that failed to become a plane
because of gravitational pull of Jupiter. Other astronomers say that the belt was a planet which broke apart during a collision. This belt has about two thousand asteroids of different sizes and shapes. The asteroid belt has its own pull of gravity and the asteroids in it goes around the sun. Astronomers say that this belt was formed as a result of planet explosion.
Even though most asteroids exist in this belt and are stuck in its gravitational pull, sometimes they shift from their positions because of impact of other asteroids that are ever floating in space. Although asteroids could damage the earth if come to close contact with it, relatively small meteors that sometimes hit the Earth are very useful to scientists in making great discoveries. These space rocks that have been chopped off of other planets like Mars or Jupiter provides an easier way of studying other planet features without having to travel long distances to the actual planets. They come to us. Asteroids are found to be fascinating and also dangerous things in space. The above is because of the difficultness of spotting every asteroid close to Earth and at any given time an asteroid is spotted to be close to the earth; the time is too short to stop it. Tracking of asteroids is very vital to the world and more money and time should be put into it.
They could mean the end of human life altogether. A majority of asteroids have moons that orbit them. Others even have other asteroids revolving around them and acting as their orbiting satellites. This is helpful to astronomers in determining asteroid properties. By measuring the
orbital distance and orbital period of the satellite, we are able to calculate the mass of an asteroid. From this, we can determine the asteroid's density and get an important hint of what the asteroid is composed of. The asteroids are not big enough to contain the atmosphere. As per scientist’s discoveries, asteroids cannot support life. From time to time, the gravitational pull of large planet disturbs the orbit of an asteroid. Asteroid characteristics in the regions of asteroid belt: Inner regions which are more reflective and have absorption bands characteristic possessed by rocky materials. The outer regions are dull and show absorption bands characteristics of carbon materials.
It’s possible for asteroids to hit the earth. But chances of this happening are minimal. Occasional gravitational tugs and collisions make asteroids to move towards the earth on highly elliptical orbits. Those which are close enough to Earth pose a threat of impact. Thousands of asteroids weighing approximately a pound are believed to fall to Earth annually. But many of these activities pass unnoticed because of the small steroids land in areas of open ocean waters or uninhabited forests,( Pravec, Petr and Harris 20).
Shards of natural space debris- naturally rocky pieces of asteroids rarely strike the earth ground because they hardly survive their journey through earth’s atmosphere. Most asteroids (between 90 to 95 %) burn up completely in the atmosphere. This results to a bright streak which is seen in the night sky. The fall of asteroids to the earth is part of the process of accretion of it from the rock of space and dust. When these fragments of rocks come very close to the earth to
be attracted by its gravitational pull, they may fall to it and become part of it. As astronomers have observed, life on earth has been impacted by collisions with these space objects. These collisions may have an effect on the Earth in the future as well. Some asteroids have orbits that at a time bring them near Earth’s surface. These are referred to as Amor objects. Some even have orbits that cross Earths orbital path. These are called Apollo objects or Earth-crossing asteroids. All objects that have a very close approach to the earth are called Near Earth Objects abbreviated as NEOS. Astronomers discovered approximately about one hundred and fifty Near Earth Objects whose widths lie between one to eight kilometres. Most of these Near Earth Objects eventually collides with the earth. These NEOs have orbits that are not stable because they are under the influence of both Mars and Earth’s gravitational pull.
Asteroids also move due to gravity. A scientist by the name Isaac Newton stated that if something is in motion, it will continue doing so until something like friction, brick wall or air resistance stops it. In this case, asteroids in motion will continue moving until the earth stops them. The space is a vacuum that is there is no air present, so asteroids at first get their pushed initially by things exploding and also dust clouds which sticks together and then no obstacle stops them. Gravity is the only thing that affects their movement. This gravity pulls them so that they move in orbits, (Kleine, et al 952). For example, sometimes we get these big curved bowls which when you drop a
coin in it, it runs in a circular motion until it reaches the hole at the centre then it drops out of sight.
The coin moves constantly as there is no object or friction to slow it down or to stop it. The above case is a bit similar to how an asteroid moves in space. Asteroids will move just like the coil until they collide with a body which the earth is stopping them. Just like the actual planets, asteroids orbit the sun. Most of the asteroids revolve around the sun between planets mars and Jupiter. Although some of them do not revolve in perfect circles, the move at varied speeds some revolving closer to planet earth. This closeness to earth means that asteroids might end up colliding with the earth. Scientists say that asteroids strike on earth wipes out approximately sixty-five million dinosaurs years ago. Just like earth and the other planets, asteroids move in space in a constant motion,( Lu Edward and Stanley, 85). These asteroids are kept in their particular orbits around the sun by the gravitational pull of the sun.
From researches and discoveries by astronomers, it can be concluded that asteroids are part of the solar system. Although they are referred to as minor planets, they have features of all other planets. They revolve around the sun and also around the other actual planets. They sometimes collide with planets although it’s rare. What makes them collide is the closeness between them and the planets as they revolve in the orbits. The pull of gravity attracts the asteroids. Many of the asteroids were out on their way to planet earth and they
appear as shooting stars in the space, (Rabinowitz, David, 166). Those which survive the journey to earth may have cause damage to the environment where they fall.
Work Cited
- Rubincam, David Parry. "Radiative spin-up and spin-down of small asteroids." Icarus 148.1 (2000): 2-11.
- Pravec, Petr, and Alan W. Harris. "Fast and slow rotation of asteroids." Icarus 148.1 (2000): 12-20.
- Kleine, T., et al. "Rapid accretion and early core formation on asteroids and the terrestrial planets from Hf–W chronometry." Nature 418.6901 (2002): 952-955.
- Lu, Edward T., and Stanley G. Love. "A gravitational tractor for towing asteroids." arXiv preprint astro-ph/0509595 (2005).
Rabinowitz, David, et al. "A reduced estimate of the number of kilometre-sized near-Earth asteroids." Nature 403.6766 (2000): 165-166.
