Iapetus Fly-by

Scientists on the Cassini mission to Saturn are poring through hundreds of images returned from the 10th September 2007 flyby of Saturn's two-toned moon Iapetus. Pictures show a white hemisphere resembling snow, and the other as black as tar.

Images show a surface that is heavily cratered, along with the mountain ridge that runs along the moon's equator. Many of the close-up observations focused on studying the strange 20-kilometer high (12 mile) mountain ridge that gives the moon a walnut-shaped appearance.

This flyby was nearly 100 times closer to Iapetus than Cassini's 2004 flyby, bringing the spacecraft to about 1,640 kilometers (1,000 miles) from the surface. The moon's irregular walnut shape, the mountain ridge that lies almost directly on the equator and Iapetus' brightness contrast are among the key mysteries scientists are trying to solve.

The return of images and other data was delayed due to a galactic cosmic ray hit which put the spacecraft into a precautionary state called safe mode. This occurred after the spacecraft had placed all of the flyby data on its data recorders and during the first few minutes after it began sending the data home. The data flow resumed later that day and concluded on Wednesday. The spacecraft is operating normally and its instruments are expected to return to normal operations in a few days.

Cassini's multiple observations of Iapetus will help to characterize the chemical composition of the surface; look for evidence of a faint atmosphere or erupting gas plumes; and map the nighttime temperature of the surface. These and other results will be analyzed in the weeks to come.

Category:

Science & Technology

Tags:

• Iapetus
• Fly-by

[MichealTea]

I Always thought that the ridges shown in the video was that of tectonic plates shifting underneath, but it shows a polar terrain. Now the dark blue,Im sure that is the warmest polar regian. The dark blue could be warm water trapped underneath the surface. And the bright red regian is as said. "Ice".

[BrunoTheQuestionable]

The dark side is warmer than the bright side, because of absorption of sunlight. This causes sublimation of any exposed ice on the dark side, and its precipitation on the bright side and at the poles. The red region in the ultaviolet image in the video is the polar ice. The dark blue region is the dark material. Liquid water may once have existed on Iapetus, but it is far too cold now.

[SkepticalZombie]

The equatorial ridge of Iapetus looks much like the mid-Atlantic ridge of our little planet.

There goes that pattern-seeking element of my brain. Cool video though, thank you again, Bruno!

[BrunoTheQuestionable]

Interesting observation. I wonder if its origin is "volcanic" but formed by water instead of lava.

[RoadRunnerLaser]

Knickers !

There seems to be one of my comments missing..

I said something along the lines of 'up to your usual standard, Bruno. Excellent material.'

[BrunoTheQuestionable]

Thanks - its appreciated.

[funkytripper]

so glad the mute function is fully operational

[BackToTheBus]

Maybe the leading hemisphere of this giant spaceship got darkened when whoever put it in orbit around Saturn used aerobraking to slow it down. 

[vettedreams]

Imagine far furure generations skiing down 10 kilometers on Iapetus on computer controlled skis, or flying over the surface in personal spacecraft while on vacation from there jobs on Mars. What wonders are in store for those humans. I hope we can someday realize the fate of this planet is in our hands and change the way we are treating it and each other.

[vettedreams]

Very Cool

[intrptr]

Though left out here, there is a titanic impact crater on one side of this moon. I was wondering if the shock waves could have circulated around, reflecting off of each other in a kind of bounce back effect that would produce that "ridge"? The whole surface looks as though its been swept by powerful forces many times over.

[WulfBand]

We give NASA Billions of dollars and what do we get back, CRAPPY pictures. They need to release the good stuff of send a Polaroid on the next flight. My 7 year old could take better pictures than NASA. If they are really that incompetent then we need to FIRE EVERYONE at NASA.

[hfcarwash]

An alien ship in disguise

[KarbineKyle]

Beautiful...

I think that Iapetus is one of the most mysterious worlds... Its 8-mile high ridge that runs ~ 800 miles lateral gives a "lollipop" kind of shape. It's very mysterious, as if two hemispheres, one darker, and the other brighter, collided to form a more spherical shape. I'm not sure, but that's an interesting theory IMO. The Universe is beautiful and chaotic... Perhaps its dark side is something like an oxide, like black iron oxide? IDK... I LOVE Science! AWESOME Video! THUMBS UP! =)

[MrVorudo]

I always thought that Iapetus was one of those reptilians spaceships disguised as harmless moons... crazy isn't it?

Sadly, by the time people realise this, it will be too late. 

[KidMoneyFresh420]

amazing