Feeds

Hubble detects new Plutonian moon

Small fourth companion for faraway icy dwarf-world

Beginner's guide to SSL certificates

A Hubble Space Telescope search for possible rings around Pluto has turned up a diminutive fourth moon orbiting the dwarf planet.

Pluto's moon P4 seen in grainy Hubble image. Pic: NASA

The body, temporarily dubbed P4, joins Charon, Hydra and Nix in the family circling the icy world. NASA says P4 is around 8 to 21 miles (13 to 34 km) in diameter, as compared to Hydra and Nix's 20 to 70 miles (32 to 113 km) and big brother Charon's 648 miles (1,043 km).

Graphic of Pluto's moons in their relative orbits. Pic: NASAP4's orbit lies between those of Hydra and Nix, which Hubble also first spotted back in 2005.

Mark Showalter of the SETI Institute in Mountain View, California, who was in charge of this Pluto obervation programme, enthused: "I find it remarkable that Hubble's cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles."

NASA's New Horizons spacecraft is due to whizz past Pluto in 2015, and Hubble's work in peering at the dwarf's "ice and molasses" surface and moons will provide useful in planning the close encounter. Alan Stern, New Horizons principal investigator, said: "This is a fantastic discovery. Now that we know there's another moon in the Pluto system, we can plan close-up observations of it during our flyby."

Regarding Pluto's elusive rings, NASA notes: "Scientists believe material blasted off Pluto's moons by micrometeoroid impacts may form rings around the dwarf planet, but the Hubble photographs have not detected any so far." ®

Bootnote

NASA says of the P4 images above: "P4 was first seen in a photo taken with Hubble's Wide Field Camera 3 on June 28. It was confirmed in subsequent Hubble pictures taken on July 3 and July 18. The moon was not seen in earlier Hubble images because the exposure times were shorter. There is a chance it appeared as a very faint smudge in 2006 images, but was overlooked because it was obscured."

Choosing a cloud hosting partner with confidence

More from The Register

next story
Ex-Soviet engines fingered after Antares ROCKET launch BLAST
Speculation rife, but Orbital claims it's too early to tell
Voyager 1 now EIGHTEEN LIGHT HOURS from home
Almost 20 BEEELION kilometres from Sol
MEN: For pity's sake SLEEP with LOTS of WOMEN - and avoid Prostate Cancer
And, um, don't sleep with other men. If that's what worries you
Jim Beam me up, Scotty! WHISKY from SPAAACE returns to Earth
They're insured for $1m, before you thirsty folks make plans
ROGUE SAIL BOAT blocks SPACE STATION PODULE blastoff
Er, we think our ISS launch beats your fishing expedition
NASA: Spacecraft crash site FOUND ON MOON RIM
'What fun!' exlaims NASA boffin who found the LADEE
BAE points electromagnetic projectile at US Army
Railguns for 'Future fighting vehicle'
OK Google, do I have CANCER?
Company talks up pill that would spot developing tumors
prev story

Whitepapers

Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Top 5 reasons to deploy VMware with Tegile
Data demand and the rise of virtualization is challenging IT teams to deliver storage performance, scalability and capacity that can keep up, while maximizing efficiency.
Mitigating web security risk with SSL certificates
Web-based systems are essential tools for running business processes and delivering services to customers.