Asteroid
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An asteroid is a minor planet that orbits within the inner solar system. It is a small object in the Solar System that travels around the Sun. It is like a planet but smaller. They range from very small (smaller than a car) to 600 miles (1000 km) across. A few asteroids have asteroid moon.
The name "asteroid" means "like a star" in the ancient Greek language. Asteroids may look like small stars in the sky, but they really do move around the Sun. Like planets, asteroids do not make their own light. Because of this, some people think "asteroids" is not a good name, and think that the name "planetoid" ("like a planet") would be a better name.
Giuseppe Piazzi found the first asteroid, in 1801. He called it Ceres, and it is the biggest object in the asteroid belt. Others, like Juno, Pallas, and Vesta were found later. In the 1850s, so many had been found that they were numbered by a Minor planet designation starting with 1 Ceres. Today, astronomers using computerized telescopes find thousands of asteroids every month. Asteroid impact prediction is one of their purposes.
Asteroids are the leftover rock and other material from the formation of the Solar System. These rocks were too small to come together to make a planet. Some are made of carbon or metal. Depending on what's on the surface, they are classified into various asteroid spectral types including Type M (metal), Type S (stone), and Type C (carbon).
Most asteroids in our Solar System are in the asteroid belt between Mars and Jupiter.[1] Many are not in the main asteroid belt. The ones that come close to Earth are called Near-Earth asteroids. Some scientists think asteroids striking the Earth killed off all the dinosaurs and caused some of the other extinction events.
Asteroid Media
Sizes of the first ten discovered asteroids, compared to the Moon
Cumulative discoveries of just the near-Earth asteroids known by size, 1980–2022
2013 EC, shown here in radar images, has a provisional designation
A top view of asteroid group location in the inner solar system.
A map of planets and asteroid groups of the inner solar system. Distances from sun are to scale, object sizes are not.
Asteroids in the solar system, categorized by size and number
Cratered terrain on 4 Vesta
A complex horseshoe orbit (the vertical looping is due to inclination of the smaller body's orbit to that of the Earth, and would be absent if both orbited in the same plane) Sun · Earth · (419624) 2010 SO16
Asteroid Template:Ats seen ejecting particles by the OSIRIS-REx
Dimorphos and the tail created after the DART impact, photo by the Hubble Space Telescope
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References
- ↑ Hogg, Helen Sawyer (1948). "The Titius-Bode Law and the Discovery of Ceres". Journal of the Royal Astronomical Society of Canada. 242: 241–246. Bibcode:1948JRASC..42..241S. Archived from the original on 18 July 2021. Retrieved 18 July 2021.