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Gorgeous Saturn

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The True Colors of Saturn and its Moons

Titan appears with Saturn behind it in this natural color view from NASA's Cassini spacecraft. NASA/JPL-Caltech/SSI.

Is there anything more lovely in the solar system than the planet Saturn? Sure, there’s Mars and the great images we’re seeing from the Curiosity rover. And, of course, Earth sports some gorgeous places. But, for sheer jaw-dropping beauty, you can’t beat a great image of Saturn and its moons. They just grab your attention.

The Cassini mission folks released a set of color “portraits” of Saturn and its largest moon Titan. They show the pair through all the seasons of Saturn’s year. And they are stunning.

A view of the night side of Titan, with sunlight scattering through the top of the atmosphere. NASA/JPL-Caltech/SSI.

A wide-angle view shows Titan passing in front of Saturn, as well as the planet’s changing colors. Upon Cassini‘s arrival at Saturn eight years ago, Saturn’s northern winter hemisphere was an azure blue.

Now that winter is encroaching on the planet’s southern hemisphere and summer on the north, the color scheme is reversing. That lovely blue is now tinting the southern atmosphere.

Saturn's rings are front and center here, obscuring part of Titan. NASA/JPL-Caltech/SSI.

The other three images depict the newly discovered south polar vortex in the atmosphere of Titan.  It’s a mass of swirling gas hovering over the pole.

Cassini‘s visible-light cameras have seen a concentration of yellowish haze in the detached haze layer at the south pole of Titan since at least March 27. Cassini‘s visual and infrared mapping spectrometer spotted the massing of clouds around the south pole as early as May 22 in infrared wavelengths. After a June 27 flyby of the moon, Cassini released a dramatic image and movie showing the vortex rotating faster than the moon’s rotation period. The four images being released today were acquired in May, June and July of 2012.

See that vortex at the south pole of Titan? It just recently formed -- and planetary scientists are studying it to understand Titan's atmospheric dynamics. NASA/JPL-Caltech/SSI.

Some of these views, such as those of the polar vortex, are only possible because Cassini’s newly inclined — or tilted — orbital path now allows more direct viewing of the polar regions of Saturn and its moons.

Over the years, Cassini has explored Enceladus and its hissing geysers, its Huygens lander probed Titan, is cameras have shown us high-resolution scans of the rings, and revealed more about the surfaces of many of Saturn’s moons.  This system continues to surprise us with each new set of images and data that Cassini sends back.

I don’t know about you, but when it comes to return on investment, I’d have to say that we’re totally getting our money’s worth out of the Cassini mission. I suspect (but I haven’t calculated it directly) that this mission has probably cost the average taxpayer a few pennies.  And, for that, we’re getting some fantastic looks at the outer solar system.

hubble space telescope, planetary science, ring system, saturn

Quadruple Saturn By-pass

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HST Captures a View of Four of Saturn’s Many Moons

So, last entry I had you examining the details of an image of a galaxy pair some 70 or so million light-years away. Today, we’re going to look at at the details of an HST image of a scene that played out some 70 or so light-minutes away at the planet Saturn.

Four of Saturns moons transiting the planet as seen by HST. (Click to embiggen -- caution-huge image!)
Four of Saturn's moons transiting the planet as seen by HST. (Click to embiggen -- caution-huge image!)

If you click on the smaller image, you’ll get a much bigger one that shows the details of a rare transit of four of Saturn’s moons:  Titan (the large one at the top of the limb of Saturn), Mimas (below Titan and casting a shadow near the rings) and bright Dione and fainter Enceladus off to the left. These transits only happen from our point of view when Saturn’s ring plane is nearly edge-on as seen from Earth.

Later this year, on August 10 and September 4, 2009, the ring plane will appear perfectly edge-on; however, we won’t be able to see that rarity because Saturn will be too close to the Sun for good viewing. These happen periodically though — in another 14-15 years we’ll get another chance to see the rings edge-on again.

Gaze at this image (particularly the large one)  for a while — note the faint banding in Saturn’s atmosphere and the sharp shadow of Saturn’s rings darkening the cloud tops.  For more information on the image and how the HST folks got it, check out the web site news release. It’s got details about the exposures used, the observation times and much more.

There’s even a nifty video sequence of four “eclipses” as the moons transit the planet.  You can see it here.

And, thanks to Andy Chaikin for pointing out that there’s an even COOLER pic of the transits on the Hubble Heritage site. Those moons are lined up quite  nicely!

A Hubble Heritage view of the Saturn transit. (Click to embiggen.)
A Hubble Heritage view of the Saturn transit. (Click to embiggen.)