If you could lick the surface of Jupiter's icy moon Europa, you would actually be sampling a bit of the ocean beneath. So says Mike Brown, an astronomer at Caltech. Brown and Kevin Hand from the Jet Propulsion Laboratory (JPL) have found the strongest evidence yet that water from the vast liquid ocean beneath Europa's frozen exterior actually makes its way to the surface.
John A. Johnson, assistant professor of planetary astronomy at Caltech, received the 2012 Newton Lacy Pierce Prize at the 221st meeting of the American Astronomical Society (AAS), in Long Beach, California.
Look up at the night sky and you'll see stars, sure. But you're also seeing planets—billions and billions of them. At least.
That's the conclusion of a new study by astronomers at the California Institute of Technology (Caltech) that provides yet more evidence that planetary systems are the cosmic norm. The team made their estimate while analyzing planets orbiting a star called Kepler-32—planets that are representative, they say, of the vast majority in the galaxy and thus serve as a perfect case study for understanding how most planets form.
The confirmed count of planets in other solar systems has skyrocketed to more than 850, plus thousands of identified candidates. The opportunity to characterize so many solar systems has brought together Caltech planetary scientists and astronomers, who are forming a Center for Planetary Astronomy.
Fifteen years after its launch, the Cassini mission to Saturn continues to give us a close-up, long-term view of the ringed planet and its astonishingly diverse collection of moons. Here are some of the highlights so far.