Scientists Boost Tally at Uranus

Uranus in lower right, its moon circled Newly discovered moon is circled; Uranus is in lower right
Image credit: P. Rousselot and O. Moussis (Observatoire de Besancon, France) and B. Gladman (University of British Columbia, Canada)
  • submit to reddit

October 25, 2002

A new moon of the planet Uranus has been discovered and confirmed by a team of astronomers including Dr. Christophe Dumas of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

This most-recently discovered natural satellite, named S/2001 U 1, brings the total number of confirmed uranian moons to 21. S/2001 U 1 and five others like it have very irregular, eccentric orbits that do not share the same orbital plane as the larger moons of Uranus. Ranging in size from 10 to 20 kilometers (about 6 to 12 miles), these moons are thought to be remnants of ancient collisions that occurred at the early stage of planetary formation.

"The irregular satellites like S/2001 U 1 are very difficult to find because they are faint and tend to be very distant from the planet," Dumas said. "It is hard to distinguish them from the background stars, and this requires special observing techniques. Because these objects formed far from the Sun, they are probably similar in composition to the most primitive objects of the solar system."

Identifying S/2001 U1 as a moon and mapping its orbit required intense effort and observation from several telescopes located in North and South America. It was first spotted by Drs. Matthew Holman of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., and J.J. Kavelaars, now at Dominion Astrophysical Observatory, Victoria, British Columbia, Canada, in August 2001 in images obtained at Cerro Tololo Observatory in Chile. Dumas and Dr. Phil Nicholson from Cornell University, Ithaca, N.Y., re-observed it from Palomar Observatory, near San Diego, Calif., a month later. The object was then followed from Chile again, using the 8-meter (26-foot) European Southern Observatory telescopes.

The discovery of the moon was a collaboration of 11 astronomers, led by Holman; Kavelaars; Dr. Brett Gladman, University of British Columbia, Vancouver, Canada; and Dr. Jean-Marc Petit, Observatoire de Besançon, Besançon, France.

JPL is a division of the California Institute of Technology in Pasadena.

Contacts: JPL/Colleen Sharkey (818) 354-0372

2002-197



Planning for NASA's 2020 Mars rover envisions a basic structure that capitalizes on the design NASA to Announce Mars 2020 Rover Instruments

› Read more

First Image of the Moon taken by a U.S. Spacecraft Moon Mission 50-Year Anniversary: A Vintage Look Back

› Read more

Elevated View of Enceladus' South Pole Cassini Spacecraft Reveals 101 Geysers and More on Icy Saturn Moon

› Read more


Get JPL Updates
Sign Up for JPL UpdatesRegister today and receive up-to-the-minute e-mail alerts delivered directly to your inbox.
Sign Up for JPL Updates