Metis (moon)

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Metis
Metis.jpg
Image of Metis was taken by Galileo's solid state imaging system between November 1996 and June 1997.
Discovery
Discovered by S. Synnott
Discovery time March 4, 1979
Orbit
Shortest distance from what it orbits around 127,974 km
Longest distance from what it orbits around 128,026 km
Avgdistance from the center of its orbital path 128,000 km (1.792 RJ)
How egg-shaped its orbit is
("eccentricity")
0.0002
How long it takes to complete an orbit 0.294780 d (7 h 4.5 min)
Average speed 31.501 km/s
Angle above the reference plane
("inclination")
0.06° (to Jupiter's equator)
What it orbits Jupiter
Size and Other Qualities
Average distance from its center to its surface 21.5 ± 2.0 km
Volume inside it ~42,700 km³
Mass 3.6 ×1016 kg
Average density 0.86 g/cm³ (assumed)
Gravity at its surface 0.005 m/s² (0.0005 g)
Slowest speed able to escape into space
("escape velocity")
0.012 km/s
How long it takes to turn around one time synchronous
Angle at which it turns
(in relation to its orbit)
zero
How much light it reflects 0.061 ± 0.003
Avg. surface temp. ~123 K

Metis or Jupiter XVI, is Jupiter's closest moon.

Metis was found in 1979 by Stephen P. Synnott in images taken by the Voyager 1 probe. Its designation was S/1979 J 3. In 1983 it was named after the mythological Metis, a Titaness who was the first wife of Zeus (the Greek equivalent of Jupiter).

Metis not a sphere and measures 60×40×34 km across. The composition and mass of Metis are not known, but assuming that its mean density is like that of Amalthea (~0.86 g/cm³), its mass can be estimated as ~7×1016 kg. Amalthea's density implies that moon is composed of water ice with a porosity of 10-15%, and Adrastea may be similar.

The surface of Metis is very cratered. It is dark and appears to be reddish in color.

Orbit[change | change source]

Metis is the closest moon to Jupiter. It orbits Jupiter at a distance of ~1269,000 km. It has a very small orbital eccentricity (~0.0002) and inclination (~ 0.06°) relative to the equator of Jupiter.

Exploration[change | change source]

The images taken by Voyager 1 showed Metis only as a dot, and very little was known about Metis until the arrival of the Galileo spacecraft. Galileo took pictures of almost all of the surface of Metis and put constraints on its composition.

Other websites[change | change source]