22 Kalliope

Orbital characteristics 1 (ftp://ftp.lowell.edu/pub/elgb/astorb.html)
Orbit type	Main belt
Semimajor axis	2.908 AU
Perihelion distance	2.608 AU
Aphelion distance	3.207 AU
Orbital period	4.96 years
Inclination	13.71°
Eccentricity	0.103
Physical characteristics 1 (ftp://ftp.lowell.edu/pub/elgb/astorb.html)
Diameter	181 km
Mass 4 (http://www.sciencemag.org/cgi/content/abstract/300/5627/1939)	7.36 × 1018 kg
Density 4 (http://www.sciencemag.org/cgi/content/abstract/300/5627/1939)	2.37 g/cm³
Rotation period 3 (http://www.psi.edu/pds/archive/lc.html)	4.148 hours
Spectral class	M
Abs. magnitude	6.45
Albedo 5 (http://dorothy.as.arizona.edu/DSN/IRAS/index_iras.html)	0.142
History 2 (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html)
Discoverer	J. R. Hind, 1852
Satellites
Name	Linus

22 Kalliope ("KALLEE o pee") is a very large Main belt asteroid discovered by J. R. Hind on November 16, 1852. It is named after Calliope, the Greek Muse of epic poetry.

Kalliope is 181 km in diameter, and is a M-type asteroid, indicating fairly pure nickel-iron composition. However, recent measurements (http://www.sciencemag.org/cgi/content/abstract/300/5627/1939) show that 22 Kalliope's density is only 2.37 g/cm³, so it must contain considerable amount of other materials.

In 2001, astronomers at the Keck telescope discovered a small moon orbiting Kalliope. It has been named Linus after the mythological figure. Linus is about 38 km in diameter and orbits about 1,000 km from Kalliope. It may be impact ejecta from a collision with Kalliope.

External links

• Data from Johnston's Archive (http://www.johnstonsarchive.net/astro/astmoons/am-00022.html)

de:Kalliope (Asteroid) es:(22) Caliope