National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Psamathe: Overview
   Back to Neptune   Overview   Gallery   Facts & Figures 
Fuzzy image showing Psamathe circled in red.
Astronomers used the Subaru 8.3 meter telescope atop Mauna Kea, Hawaii to pinpoint tiny Psamathe.

Psamathe is so distant from Neptune it takes almost 26 Earth years to make a single orbit around the ice giant. The moon's orbit is among the most distant from its planet than any other known moon in our solar system.

The small moon shares similar orbital parameters with with another moon of Neptune -- Neso. Both Psamathe and Neso may be fragments from the break-up of a larger moon billions of years ago.

Psamathe was discovered by Scott S. Sheppard, David C. Jewitt and Jan T. Kleyna 29 August 2003 using the 8.3-m Subaru reflector at the Mauna Kea Observatory on the island of Hawaii.

How Psamathe Got its Name:
Moons of Neptune are named for characters from Greek or Roman mythology associated with Neptune or Poseidon, or the oceans. Irregular satellites are named for the Nereids, daughters of Nereus and Doris and the attendants of Neptune.

Psamathe like many of the satellites of Neptune, is named after one of the Nereids. Psamathe was originally designated S/2003 N 1.

Just the Facts
Orbit Size (semi-major axis):  29,885,469 miles
Mean Radius:  12.4 miles
People Spotlight
Carl Sagan Carl Sagan
Astronomer Carl Sagan was often described as "the scientist who made the Universe clearer to the ordinary person." Read More...
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 6 Feb 2014