What is an asteroid: summary for children

The name of asteroid comes from Greek, where it meant ‘star shape’ and was named by the British-born astronomer John Herschel (1738-1822). As mentioned, the asteroids are rocky bodies floating around the sun .

When asteroids are in the process of colliding with Earth they are called meteoroids . However, when these rub against and are deflected by the atmosphere, they release an energy that generates a combustion that releases a ray of light known as a meteor .

Sometimes the metoroid is consumed as it passes through the atmosphere, but leaves residues of different sizes called meteorites . If these meteorites are of a considerable size, they can impact on the earth’s surface and produce important climatic changes and in the earth’s relief. For example, the relief of our planet has been modified in the past by the impact of large meteorites, which have also caused important extinctions, as in the case of the extinction of the dinosaurs .

The formation of asteroids has taken place during the shaping of our Solar System . During this period, residues have remained as a result of the death of some stars. The debris that has not joined any planet or asteroid, remained orbiting in space and has formed asteroids. It is possible to find asteroids throughout our Solar System, but one of the densest found is the asteroid belt of the planet Jupiter, which does not allow the evolution of life.

Most asteroids are found forming what we know as the main belt or asteroid belt , which is an orbit around the Sun , between the planets of Mars and Jupiter. There are also some asteroids that cross the orbit of the Earth, although of those currently known there are none that have a collision path with the Earth, although important collisions have occurred over time.

Recently, the number of existing asteroids has been estimated between 1.1 and 1.9 million . In general, the size of asteroids is variable, although most are small. Only about 16 asteroids of those cataloged have a diameter greater than 240 kilometers.

For example, the asteroid Siwa has a diameter of 103 km. One of the first asteroids discovered was Ceres, which with its 1000 km in diameter is almost considered a dwarf planet. Another large asteroid is Pallas, about 532 km in diameter.

There are an estimated 800 potentially dangerous asteroids (PHAs). Damage from a potential asteroid impact with Earth can range from local disasters to mass extinctions.

Various impacts have been found throughout terrestrial history. One of them was the one that caused the extinction of approximately 90% of life on Earth during the Permian or the great asteroid that hit Yucatán (Mexico) at the end of the Cretaceous and that could cause the disappearance of the dinosaurs .

Even a large part of scientists believe that life could reach Earth as a result of asteroids that impacted on the surface and that generated complex molecules of carbon, organic compounds and water that allowed the development of later life.

The name by which asteroids are called consists of a number that represents the year of discovery and a first letter that denotes the fortnight of their discovery (in a 25-letter alphabet). The second letter denotes the order in which it was discovered during that fortnight. Once the letters are finished, we start by putting numbers in sequences, so that, for example, A1 would be the discovered in place 26.

For example, the asteroid 2003 QQ47, has been discovered in the year 2003 during the second half of August (Q) and in order 16 (the Q is the sixteenth letter) X 47, therefore, it would be the number 752 discovered during that fortnight.