Meteors and Meteorites
Meteors are small bits of rock or grains of dust that usually come from comets, and these burn up when they pass through the Earth’s atmosphere. They are also known as shooting stars.
Comets create a stream of dust and when Earth passes through this stream it produces meteor showers.
There are several meteor showers that occur at certain times of the year and their names come from where the meteor shower ‘radiates’ from.
The Orionids appear to come from the constellation of Orion.
The Leonids appear to come from the constellation of Leo.
The Geminids appear to come from the constellation of Gemini.
When a meteor hits the Earth’s surface this is known as a meteorite and it usually comes from an asteroid.
When a meteorite hits a sandstone region, the heat melts the minerals in the soil forming small, round, glassy objects called Tektites.
The three types of meteorites are Stone, Iron, and Stony Iron.
Asteroids are leftover rock and metal that did not become planets or moons. Scientists think that Jupiter’s enormous gravity flung the debris into various orbits, and some of the larger asteroids smashed together and broke up.
Many of the pieces of rock form a ring that orbits the Sun between Jupiter and Mars and this is known as the Asteroid Belt, but some have been flung into erratic orbits by Jupiter’s gravity.
The Asteroid Belt separates the rocky planets from the gas giants.
Asteroids range in size from a few hundred feet wide to about 500 miles (800 km) in diameter.
The first asteroid to be discovered was Ceres on 1 January 1801 by Guiseppe Piazze. Since then more than 500,000 asteroids have been discovered.
The five largest asteroids are known as dwarf planets:
Eris – 2,326km diameter
Pluto – 2,374km diameter
Ceres (seer-ees) – 950km diameter
Haumea (hah-oo-may-ah) – 996 km pole diameter, 1,960km equatorial diameter
Makemake (mah-kee-mah-kee) – 1,434km at the equator, 1,422km at the pole
Eris is about the same diameter as Pluto.
Haumea is shaped like a potato and has two moons called Namaka and Hi’iaha.
Makemake takes 310 years to orbit the Sun.
A spaceship called Dawn has visited the asteroids Vesta and Ceres, and if a spaceship was sent straight to Ceres it would take a year to reach it.