Psamathe (moon)
Encyclopedia
Psamathe also known as Neptune X, is a retrograde
irregular satellite of Neptune
. It is named after Psamathe
, one of the Nereids. This moon was discovered by Scott S. Sheppard
and David C. Jewitt
in 2003 using the 8.2 meter Subaru telescope. Before the announcement of its name on February 3, 2007 (IAUC 8802), it was known by the provisional designation S/2003 N 1.
This moon is about 38 kilometers in diameter. It orbits Neptune at a distance of about 46,695,000 km and requires almost 25 Earth years to make one orbit. The orbit of this satellite is close to the theoretical stable separation from Neptune for a body in a retrograde orbit. Given the similarity of this moon's orbital parameters with Neso (S/2002 N 4), it was suggested that both irregular satellites could have a common origin in the break-up of a larger moon. Both are further from their primary than any other known moon in the Solar System.
Retrograde motion
Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...
irregular satellite of Neptune
Neptune's natural satellites
Neptune has thirteen known moons, by far the largest of which is Triton, discovered by William Lassell on October 10, 1846, just 17 days after the discovery of Neptune itself. Over a century passed before the discovery of the second natural satellite, called Nereid...
. It is named after Psamathe
Psamathe
Psamathe was a Nereid in Greek mythology, i.e., one of the fifty daughters of Nereus and Doris. The goddess of sand beaches, Psamathe was the wife of Proteus and the mother of Phocus by Aeacus....
, one of the Nereids. This moon was discovered by Scott S. Sheppard
Scott S. Sheppard
Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...
and David C. Jewitt
David C. Jewitt
David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in...
in 2003 using the 8.2 meter Subaru telescope. Before the announcement of its name on February 3, 2007 (IAUC 8802), it was known by the provisional designation S/2003 N 1.
This moon is about 38 kilometers in diameter. It orbits Neptune at a distance of about 46,695,000 km and requires almost 25 Earth years to make one orbit. The orbit of this satellite is close to the theoretical stable separation from Neptune for a body in a retrograde orbit. Given the similarity of this moon's orbital parameters with Neso (S/2002 N 4), it was suggested that both irregular satellites could have a common origin in the break-up of a larger moon. Both are further from their primary than any other known moon in the Solar System.
External links
- Neptune's Known Satellites (by Scott S. SheppardScott S. SheppardScott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...
) - S/2003 N1 Neptune Satellite Movie Images (image)
- MPC: Natural Satellites Ephemeris Service
- Mean orbital parameters (NASA)
- IAUC 8193