Outer Planets

Jupiter. Saturn. Uranus. Neptune. Each of these giant planets is the center of its own miniature solar system. Each is spectacularly beautiful and scientifically fascinating, which are reasons enough to explore them. But by studying the giant planets and their rings and moons, we can also learn about the forces that operated during the formation of our own solar system, as well as the origins of the hundreds of new extrasolar planetary systems that we discover every year.

And their moons are worlds in their own right. There are at least 16 outer planetary moons that would be called dwarf planets if they orbited the Sun rather than a planet. Two (Jupiter's Ganymede and Saturn's Titan) are larger than the planet Mercury, and one (Triton) is probably a captured Kuiper belt object.

But it is challenging and expensive to explore the outer planets, and missions to the outer planets take a very long time to develop, fly, and operate. Cassini will be orbiting Saturn until 2017, and Juno will operate at Jupiter from 2016 to 2017. After that, it's not clear if anyone will be sending a followup mission to Saturn or Jupiter or its moons, or an orbiter to survey the Uranus or Neptune systems. And there is a critical shortage of the isotope of plutonium that is needed to generate power for outer planetary missions.

Lesser-known views of Uranus and Neptune

Posted by Emily Lakdawalla on 2013/05/28 10:58 CDT | 7 comments

Despite the fact that Voyager 2 returned relatively few high-resolution images from either Uranus or Neptune, there are many more photos in the archives than regularly make it to public view.

The Shores of the Kraken Sea: Great Place Names in the Solar System

Posted by Bill Dunford on 2013/05/28 08:59 CDT | 9 comments

Nothing reflects the romance of deep space exploration more than the evocative names of places on the planets and moons.

A serendipitous observation of tiny rocks in Jupiter's orbit by Galileo

Posted by Emily Lakdawalla on 2013/05/17 09:54 CDT | 3 comments

A look at an older paper describing Galileo's possible sighting of individual ring particles orbiting Jupiter as companions to its inner moon Amalthea.

Mimas and Pandora dance

Posted by Emily Lakdawalla on 2013/05/15 05:02 CDT | 6 comments

I've been out of town for a couple of days and am overwhelmed with work and an overflowing email box. So what do I do about that? I ignore what I'm supposed to be doing and play with Cassini raw image data, of course. Here is a "mutual event" of Mimas (the bigger moon) and Pandora (the outer shepherd of the F ring).

Doing a science on Titan

Posted by Sarah Hörst on 2013/05/15 11:55 CDT | 12 comments

A tale from the scientific trenches: laboratory work to simulate Titan's rich atmosphere.

One of my favorite image processing tricks: colorizing images

Posted by Emily Lakdawalla on 2013/04/23 02:11 CDT | 2 comments

An easy image processing trick -- using lower-resolution color data to colorize a black-and-white photo -- is relied upon by many space missions to keep data volumes low. Here's how to do it.

Jupiter Seen Through Methane Band Filter

In a New Light

Posted by Bill Dunford on 2013/04/15 02:08 CDT | 3 comments

Cassini's unique views of Jupiter and Saturn.

Planetary Society Weekly Hangout: The Ice Giants, with Heidi Hammel

Posted by Emily Lakdawalla on 2013/04/11 02:00 CDT | 5 comments

My guest this was Planetary Society Board vice president Heidi Hammel. We discussed two planets near and dear to our hearts, Neptune and Uranus. What's new on these icy worlds since Voyager 2 passed by, and what are the prospects for their future exploration?

One Day in the Solar System

Posted by Bill Dunford on 2013/04/08 09:12 CDT | 4 comments

Dispatches from five different worlds--all sent by robotic spacecraft on the same day.

Planetary Society Weekly Hangout: Reports from the Lunar and Planetary Science Conference

Posted by Emily Lakdawalla on 2013/03/28 02:00 CDT | 5 comments

On Thursday at noon PDT / 1900 UTC I'll report on some of my favorite findings from LPSC, and answer your questions about the latest planetary science.