Science In The Pub Adelaide

Asteroids

If there are space objects that everyone is familiar with, it would be asteroids. From depiction in books to cinemas, asteroids have acquired a sensational reputation of their own. These objects are rocky worlds that are too small to be considered planets. Like other planets, they revolve around the sun and are sometimes referred to as minor planets or planetoids. Millions of asteroids exist in space with size ranging from several feet to hundreds of miles. The sum of the mass of all asteroids is below that of the moon.

astro

How Asteroids Are Formed

Asteroids are what remained from the formation of the solar system around 4.6 billion years ago. In the beginning, the formation of Jupiter made it impossible for any other planetary body to go in the space between Jupiter and Mars. This made the small objects within that space to collide, and they split into fragments that are called asteroids today.

The understanding of the evolution of the solar system is a continuous process with discoveries every day. Two of the newest theories, the Grand Tack and the Nice model, posits that the gas giants didn’t just settle into their modern orbits immediately, they moved around first. It is possible that this movement made asteroids in the man belt to rain on the terrestrial planets.

Physical Characteristics

The largest asteroid known is Ceres at 940 kilometres in width, and the smallest was the 2015 TC25 space rock which was 2 metres wide when observed in 2015 as it flew close to the earth. Generally, asteroids are unevenly shaped, although some of the biggest usually have a near-spherical shape. Most asteroids have their surface covered in dust.

Asteroids rotate as they revolve in elliptical orbits as they revolve around the sun and it is not strange to find them tumbling. Over 150 asteroids have their companion moon with some even having up to two moons. There are also double or binary asteroids where two asteroids with similar size orbit each other as well as triple asteroids. The average temperature of an asteroid surface is -75 degrees Celsius.