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.
The Cassini mission has already returned an array of images of other solar system members from Saturn orbit: Earth (and the Moon), Venus, Mars, and Jupiter. It’s time to add another world to that list!
Posted by Bruce Betts on 2014/04/11 02:31 CDT
Examine Saturn's moon Titan and explore the Uranian and Neptunian systems in this video of class 9 of Bruce Betts' Introduction to Planetary Science and Astronomy class.
Posted by Bruce Betts on 2014/04/11 02:28 CDT
Explore the icy moons of the Jupiter System and tour the Saturnian system in this video of class 8 of Bruce Betts' Introduction to Planetary Science and Astronomy class.
Vignettes from dozens of LPSC talks: GRAIL and LADEE at the Moon; ice and craters and conglomerates and organics and gullies on Mars; polar deposits and volatile elements on Mercury; tectonics on Enceladus; and more, until my brain was so full I could barely speak.
Posted by Bruce Betts on 2014/03/21 02:10 CDT
Examine the threat of near Earth asteroids and begin exploring the Jupiter System in this video of class 7 of Bruce Betts' Introduction to Planetary Science and Astronomy class.
Simon Kattenhorn and Louise Prockter may finally have found subduction zones on Europa, which would it the only other place in the solar system besides Earth that is known to have active plate tectonics.
It's happened again; I went into the Cassini image archive looking for something specific and wound up spending several hours playing with totally unrelated image data. Here are several beautiful images of the rings from the archives.