Astrophysics (Index)About

asteroid

(minor planet without comet characteristics)

The term asteroid is used for minor planets in the asteroid belt, out to Jupiter's orbit. It is also used more generally: often to include minor planets closer to the Sun, such as those that are near-Earth objects, and sometimes to include centaurs, i.e., minor planets further out. Vulcanoids are a theoretical population of asteroids within the orbit of Mercury (which would be difficult to detect).

The first discovered asteroids were Ceres and Pallas (now designated 1 Ceres and 2 Pallas) in 1801, with the 15th discovered in 1851. The term asteroids means star-like: they appeared as points though they move like planets. Now 100,000 have been identified, many by computer, and the estimated population is millions. Among the largest are Juno (3 Juno), Vesta (4 Vesta) and Hygiea (10 Hygiea).

A diameter of 10 meters is often (but not always) used as the threshold between asteroid and meteoroid. Ceres, the largest in the asteroid belt, is near 1,000 km in diameter, the next largest with less than 600 km. Asteroids are generally classified by type of orbit and by spectrum.


(minor planets,solar system,object type)
Further reading:
http://en.wikipedia.org/wiki/Asteroid

Referenced by pages:
asteroid belt
asteroid family
axisymmetric
101955 Bennu
binary minor planet (BMP)
Ceres
chondrite
Campo Imperatore Near-Earth Object Survey (CINEOS)
circumstellar disk
collisional erosion
cosmic dust
Catalina Sky Survey (CSS)
Dawn
Deep Space 1 (DS1)
Galileo
IRAS
Kirkwood gap
Kozai mechanism
Kuiper Belt (K Belt)
Lagrangian point
late heavy bombardment (LHB)
LINEAR
LONEOS
Mars crosser (MC)
mass extinction
mass spectrometer
Maxwell-Boltzmann distribution
meteoroid
minor planet
Moon formation
Minor Planet Center (MPC)
NEAR Shoemaker (NEAR)
near-Earth object (NEO)
Nearby Supernova Factory (NSNF)
occultation observations
orbital resonance
OSIRIS-REx
Planet Crossing Asteroid Survey (PCAS)
Planet Nine
planetary embryo
planetesimal
planetoid
primordial black hole
protoplanet
Psyche
Palomar Transient Factory (PTF)
regolith
supernova survey
solar system
SPACEWATCH
SSSB
Teegarden's Star
Titius-Bode law
Uppsala-ESO Survey of Asteroids and Comets (UESAC)
Wide-field Infrared Survey Explorer (WISE)
Yarkovsky effect
Yarkovsky-O'Keefe-Radzievskii-Paddack effect (YORP)

Index