Click on image for full size
Image courtesy European Southern Observatory.

New Moons of Uranus and Neptune
News story originally written on October 31, 2003

Astronomers have discovered new moons orbiting the planets Uranus and Neptune. Counting the new moons, Uranus now has 27 moons that we know about. Neptune has 13 that have been found so far. All of the newfound moons are small, having diameters less than 100 km (60 miles).

Mark Showalter of Stanford University and NASA's Ames Research Center and Jack Lissauer of Ames discovered two new moons of Uranus. Those moons have been given temporary names: S/2003 U1 and S/2003 U2. The moons were found in pictures taken by the Hubble Space Telescope. Uranus has five large moons named Ariel, Miranda, Oberon, Titania and Umbriel. S/2003 U1 and S/2003 U2 are closer to Uranus than all of the large moons.

Scott Sheppard and David Jewitt discovered two more moons of Uranus. Those moons are called S/2003 U3 and S/2001 U2 for now. Sheppard and Jewitt used a telescope on top of a volcano in Hawaii to find these moons. S/2001 U2 has a big orbit and takes almost 8 years to go around Uranus!

Astronomers also found two new moons orbiting Neptune. Matthew Holman and B. Gladman discovered S/2002 N4. Jewitt, Sheppard and Jan Kleyna discovered S/2003 N1. These moons orbit very far from Neptune. They are farther away from their "home" planet than any other moon that has been found so far. They take about 25 years to go around Neptune once!

Some of the moons had been seen before in the last few years. To figure out the orbit of a moon, astronomers need to see it a few times to know how it moves. They don't count a moon as "discovered" until they are sure that it orbits a planet.

Last modified October 31, 2003 by Randy Russell.

You might also be interested in:

Miranda

Miranda was discovered by G. Kuiper in 1948. It has a standoff distance of 129,780 km. Miranda one of the smallest icy moons, and is as wide as the distance from Los Angeles to San Francisco, being 47...more

Oberon

Oberon was discovered by W. Herschel in 1787. It has a standoff distance of 582,600 km. Oberon is about as wide as the state of California is long, being 1520 km (1013 miles) in size. The surface features...more

Titania

Titania was discovered by W. Herschel in 1787. It has a standoff distance of 435,840 km. Titania is about as wide as the state of California is long, being 1580 km (1053 miles) in size. The surface features...more

Umbriel

Umbriel was discovered by W. Lassell in 1851. It has a standoff distance of 265,970 km. Umbriel is about as wide as the Oregon coast line, being 1170 km (780 miles) in size. The surface features of this...more

More and more Moons of Jupiter

Astronomers have discovered twelve new moons of Jupiter so far in 2003. Jupiter now has a total of 52 moons that we know of. Jupiter, the largest planet in our Solar System, has more moons than any other...more

Mars Opposition in August 2003

On August 27, 2003, Earth and Mars will be closer together than they have been in thousands of years. Mars will pass within 55,758,006 kilometers (34,646,418 miles) from Earth. Astronomers have calculated...more

More Moons around Jupiter & Saturn

Astronomers have recently discovered nine new moons. The astronomers found eight new moons of Jupiter and one new moon of Saturn. We now know of 60 moons orbiting Jupiter and 31 orbiting Saturn. The new...more

Mercury Transit on May 7, 2003

The planet Mercury appeared to cross in front of the Sun on May 7, 2003. Astronomers call the event a transit. A transit is like a solar eclipse. However, a transit occurs when a planet, instead of Earth's...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA