Mneme , also known as , is a retrograde

irregular satellite In astronomy, an irregular moon, irregular satellite, or irregular natural satellite is a natural satellite following an orbit that is irregular in some of the following ways: Distant; inclined; highly elliptical; retrograde. They have often be ...

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

. It was discovered by teams of astronomers led by Brett J. Gladman and Scott S. Sheppard in 2003, and was provisionally designated S/2003 J 21. Mneme is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 21,427,000 kilometres in 640.769 days, at an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 149° to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

(148° to Jupiter's equator) with an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.2214. Its average orbital speed is 2.43 km/s. It was named in March 2005 after Mneme, one of the three original

Muse In ancient Greek religion and Greek mythology, mythology, the Muses (, ) were the Artistic inspiration, inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the poetry, lyric p ...

s.IAUC 8502: ''Satellites of Jupiter''
2005 March 30 (naming the moon) She is sometimes confused with

Mnemosyne In Greek mythology and ancient Greek religion, Mnemosyne (; , ) is the goddess of memory and the mother of the nine Muses by her nephew Zeus. In the Greek tradition, Mnemosyne is one of the Titans, the twelve divine children of the earth-godde ...

, mother of the Muses (the three or the nine, depending on the author) by

Zeus Zeus (, ) is the chief deity of the List of Greek deities, Greek pantheon. He is a sky father, sky and thunder god in ancient Greek religion and Greek mythology, mythology, who rules as king of the gods on Mount Olympus. Zeus is the child ...

(Jupiter). Mneme belongs to the Ananke group, retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 million kilometres, at inclinations of roughly 150°.

References

Ananke group Moons of Jupiter Discoveries by Brett J. Gladman Discoveries by Scott S. Sheppard Irregular satellites 20030209 Moons with a retrograde orbit {{Jupiter-stub