149 Medusa

Infobox Planet | minorplanet = yes | width = 25em | bgcolour = #FFFFC0
name=149 Medusa
discovery=yes
discovery_ref= [http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html]
discoverer=Henri Joseph Perrotin
discovered=September 21, 1875
alt_names=
mp_category=Main belt
orbit_ref= [ftp://ftp.lowell.edu/pub/elgb/astorb.html]
epoch=December 31, 2006 (JD 2454100.5)
semimajor=325.284 Gm (2.174 AU)
perihelion=304.026 Gm (2.032 AU)
aphelion=346.542 Gm (2.316 AU)
eccentricity=0.065
period=1171.128 d (3.21 a)
inclination=0.937°
asc_node=159.647°
arg_peri=251.134°
mean_anomaly=284.523°
avg_speed=20.18 km/s
physical_characteristics=yes
dimensions=19.7 km
mass=8.0e|15 kg
density=2.0 g/cm³
surface_grav=0.0055 m/s²
escape_velocity=0.0104 km/s
sidereal_day=? d
axial_tilt=?° | pole_ecliptic_lat=? | pole_ecliptic_lon=?
spectral_type=S
abs_magnitude=10.79
albedo=0.10
single_temperature=~189 K

149 Medusa is a bright-coloured, stony main belt asteroid.

It was discovered by J. Perrotin on September 21, 1875 and named after the Gorgon Medusa, a snake-haired monster in Greek mythology.

When it was discovered, Medusa was by far the smallest asteroid found (although this was not known at that time). Since then, many thousands of smaller asteroids have been found. It was also the closest asteroid to the Sun discovered up to that point, beating the long-held record of 8 Flora. It remained the closest asteroid to the Sun until 433 Eros and 434 Hungaria were found in 1898, leading to the discovery of two new families of asteroids inward from the 4:1 Kirkwood gap which forms the boundary of the main belt.

It has also a rather long rotation period of 26 hours.