Feeds

Phoebe's past writ large in craters

Saturn's moon shows its age

  • alert
  • submit to reddit

The smart choice: opportunity from uncertainty

Those craters in detailPhotographs from Cassini's flyby of Saturn's moon Phoebe have revealed a battered body, with an interesting past. Its face is pock-marked with craters ranging from 80 kilometers across to less than one kilometer, with variations in colour suggesting it contains plenty of ice.

The larger impact sites have prompted speculation that collisions in Phoebe's past could have blasted off enough material to have formed Saturn's smaller retrograde moons.

The brighter craters are most likely the newer impacts. Each collision would have blasted off surface material, and exposed brighter material, possibly ice, below the surface. There is more evidence for this theory on the crater walls: darker material seems to have slid down slope, exposing more light-colored material.

"What we are seeing is very neat. Phoebe is a heavily cratered body. We might be seeing one of the chunks from the formation of the solar system, 4.5 billion years ago. It's too soon to say," said Dr. Torrence Johnson, from NASA's Jet Propulsion Laboratory. "It's important to see the big picture from all of the other instruments to get the global view on this tiny moon."

All 11 of Cassini's instruments were pointed at the moon as the spacecraft flew by, just over 2000km above the surface. The data will be analysed over the next few days and will help scientists to build global maps of the moon, and to determine its composition, mass and density. ®

Related stories

Mysterious Phoebe: Cassini's next fly-by
Cassini images delight star gazers
Comet chasers seek secret of life

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
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.