Feeds

Neptune shows off five new moons

Gas giants battle for headlines

  • alert
  • submit to reddit

The smart choice: opportunity from uncertainty

A team of international astronomers has found five new moons orbiting Neptune. Previously the planet had seven known moons, including a couple of oddities: Triton and Nereid. The moons were discovered in observations made from ground-based telescopes in Chile and Hawaii.

It is almost as if the larger planets of our solar system are trying to out-do one another: earlier this week stargazing scientists spotted two new mini-moons around Saturn.

The scientists made their observations using the 3.6-meter Canada-France-Hawaii telescope in Hawaii, and the 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile. These cameras were originally developed to hunt for Kuiper Belt objects.

Two of the new moons have prograde orbits - that is, they orbit in the same direction as the planet turns. The remaining three, however, have retrograde orbits.

The other gas giants have both kinds of moons, and they behave quite consistently. Prograde moons tend to be more regular in shape, have more circular orbits, and are thought to have formed along with their planet. Retrograde moons, by contrast, are irregular lumps, and are generally captured pieces of space junk. They have more elliptical orbits, often at inclined planes.

In the midst of all this consistent behaviour, Neptune was something of an oddity. Triton, an irregular shaped body about the size of Pluto, is in a retrograde but circular orbit, while the much smaller Nereid follows a highly eccentric orbital path in a prograde direction. Adding five more normal moons to the mix smoothes the weirdness out, a little.

The astronomers, led by Matthew Holman of the Harvard-Smithsonian Center for Astrophysics, took a long series of exposures using the wide-field mosaic CCD cameras on the two telescopes. They then digitally combined the images to look for small moving objects that were too faint to be resolved in a single shot.

Neptune's newly identified companions are all between 30km and 50km in diameters. This suggests they are most likely re-captured fragments from collisions between larger orbiting bodies, the team says. ®

Related stories

Cassini finds two tiny Saturnian moons
Aurora rattles tin for space exploration
Red moonlight to bathe UK
Lawyers claim earth, sky and moon from Microsoft

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.