English: Asteroid

A photo of asteroid (253) Mathilde taken by NEAR

An asteroid is a space rock. 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, while stars only seem to move because the Earth spins. 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 the 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. Many are not in the main asteroid belt. The ones that come close to Earth are called Near-Earth asteroids. Many scientists think asteroids striking the Earth killed off all the dinosaurs and caused some of the other extinction events.

Other Languages
Afrikaans: Asteroïde
Alemannisch: Asteroid
العربية: كويكب
aragonés: Asteroide
অসমীয়া: গ্ৰহাণু
asturianu: Asteroide
Avañe'ẽ: Mbyjaveve
azərbaycanca: Asteroid
تۆرکجه: گزگنچه
বাংলা: গ্রহাণু
Bahasa Banjar: Asteruid
Bân-lâm-gú: Sió-he̍k-chheⁿ
башҡортса: Астероид
беларуская: Астэроід
беларуская (тарашкевіца)‎: Астэроід
भोजपुरी: एस्टेरॉइड्स
български: Астероид
Boarisch: Asteroid
bosanski: Asteroidi
brezhoneg: Asteroidenn
català: Asteroide
Чӑвашла: Астероид
čeština: Asteroid
Cymraeg: Asteroid
dansk: Asteroide
Deutsch: Asteroid
eesti: Asteroid
Ελληνικά: Αστεροειδής
emiliàn e rumagnòl: Asteròid
English: Asteroid
español: Asteroide
Esperanto: Asteroido
euskara: Asteroide
فارسی: سیارک
Fiji Hindi: Chhota tara
français: Astéroïde
Frysk: Asteroïde
Gaeilge: Astaróideach
Gaelg: Roltageagh
galego: Asteroide
한국어: 소행성
հայերեն: Աստղակերպ
hornjoserbsce: Asteroid
hrvatski: Asteroidi
Ilokano: Asteroid
Bahasa Indonesia: Asteroid
interlingua: Asteroide
íslenska: Smástirni
italiano: Asteroide
עברית: אסטרואיד
Jawa: Asteroid
Kapampangan: Asteroyde
къарачай-малкъар: Астероид
қазақша: Астероид
Kiswahili: Asteroidi
Kreyòl ayisyen: Astewoyid
kurdî: Asteroîd
Кыргызча: Астероид
Latina: Asteroides
latviešu: Asteroīds
Lëtzebuergesch: Asteroid
лезги: Астероид
lietuvių: Asteroidas
Limburgs: Planetoïed
lumbaart: Asteroide
magyar: Kisbolygó
македонски: Астероид
Malagasy: Asterôida
മലയാളം: ഛിന്നഗ്രഹം
Malti: Asterojde
मराठी: लघुग्रह
მარგალური: ასტეროიდი
Bahasa Melayu: Asteroid
Baso Minangkabau: Asteroid
Mirandés: Asteróide
မြန်မာဘာသာ: ဥက္ကာပျံ
Nederlands: Planetoïde
日本語: 小惑星
Napulitano: Asteroide
нохчийн: Астероид
Nordfriisk: Asteroiid
norsk: Asteroide
norsk nynorsk: Asteroide
occitan: Asteroïde
oʻzbekcha/ўзбекча: Asteroid
پنجابی: تارے ورگا
Patois: Astaraid
Piemontèis: Asteròid
Plattdüütsch: Asteroid
polski: Planetoida
português: Asteroide
Qaraqalpaqsha: Asteroid
Ripoarisch: Asteroid
română: Asteroid
Runa Simi: Puriq quyllurcha
русиньскый: Астероід
русский: Астероид
саха тыла: Астероид
Scots: Asteroid
Seeltersk: Planetoiden
shqip: Asteroidet
sicilianu: Astiròidi
සිංහල: ග්‍රහක
slovenčina: Asteroid
slovenščina: Asteroid
српски / srpski: Астероид
srpskohrvatski / српскохрватски: Asteroid
Basa Sunda: Astéroid
suomi: Asteroidi
svenska: Asteroid
Tagalog: Asteroyd
தமிழ்: சிறுகோள்
Taqbaylit: Azunyur
татарча/tatarça: Астероидлар
తెలుగు: గ్రహశకలం
тоҷикӣ: Астероид
Türkçe: Asteroit
Türkmençe: Asteroid
тыва дыл: Астероид
українська: Астероїд
اردو: سیارچہ
vèneto: Asteroide
Tiếng Việt: Tiểu hành tinh
文言: 小行星
West-Vlams: Asteroïde
Winaray: Asteroyd
吴语: 小行星
ייִדיש: אסטערויד
粵語: 小行星
žemaitėška: Asteruoids
中文: 小行星