Outer Solar System

Capturing Sedna: A Close Stellar Encounter?

June 24, 2015

With New Horizons scheduled for its flyby of Pluto/Charon in a matter of weeks and a Kuiper Belt extended mission to follow, it’s interesting to note a new paper on objects well beyond Pluto’s orbit. Lucie Jílková (Leiden Observatory) and colleagues address the problem of Sedna and recently discovered 2012VP113. The problem they present is […]

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Charon’s ‘Dark Pole’

June 23, 2015

An abrupt change: I’m holding today’s post (about halfway done, on a stellar flyby that may have produced Sedna and other such objects long in our system’s past) to turn to New Horizons’ latest imagery, which is provocative indeed. We’ll cover the Sedna story tomorrow. What we have from New Horizons is the work of […]

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New Insights into Titan

June 19, 2015

It’s hard to consider a place with surface temperatures of –180°C ‘Earthlike,’ but there are reasons why we see the term so often applied to Titan. The most striking of these is the presence of surface lakes and seas, a phenomenon found nowhere else in the Solar System. The temperatures are cold enough to make […]

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Pluto: Surface Features Emerging

June 12, 2015

New imagery from New Horizons continues to dazzle, with the images below taken by the spacecraft’s Long Range Reconnaissance Imager (LORRI) instrument from May 29 to June 2. We’re beginning to pick up bright areas mixed with dark terrain in what are clearly the best images ever obtained of the remote world. As before, mission […]

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Ceres Up Close (and a Bit of Bradbury)

June 11, 2015

I know I’m going to remember the summer of 2015 for a long time. The confluence of deep space missions has brought new images every week, including the latest view of Ceres and its enigmatic bright spots, which appears below. I’m already bracing myself for that Voyager-like sense of deflation once New Horizons gets past […]

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Into Plutonian Depths

May 28, 2015

The image of Pluto on the right — an artist’s impression, to be sure (credit: NASA, ESA and G. Bacon, STScI) — suggests Ganymede to me more than Pluto, but we’ll have to wait and see what New Horizons turns up as it continues to close on its target. It’s worth thinking about how our […]

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Sea Salt in Europa’s Dark Materials?

May 14, 2015

‘Europa in a can’ may be the clue to what’s happening on Jupiter’s most intriguing moon. Created by JPL’s Kevin Hand and Robert Carlson, ‘Europa in a can’ is the nickname for a laboratory setup that mimics conditions on the surface of Europa. It’s a micro-environment of extremes, as you would imagine. The temperature in […]

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A New Look Inside Enceladus

May 7, 2015

We can hope that plumes like those found emanating from the south pole of Enceladus happen on other icy worlds. There have been hints of plumes at Europa but they’ve proven elusive to pin down. However, we’re learning a great deal about the water inside Enceladus through Cassini flybys, using models based on mass spectrometry […]

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Pluto/Charon: Surface Features Emerging

April 30, 2015

One of the more memorable moments from yesterday’s teleconference on the New Horizons mission was Alan Stern’s comment that the latest pixelated images of Pluto/Charon constituted his ‘meet Pluto moment.’ If anyone has an interest in meeting Pluto, it’s Stern (Southwest Research Institute), who serves as principal investigator and whose unflagging efforts made it possible. […]

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Ganymede Bulge: Evidence for Its Ocean?

April 8, 2015

What to make of the latest news about Ganymede, which seems to have a bulge of considerable size on its equator? William McKinnon (Washington University, St. Louis) and Paul Schenk (Lunar and Planetary Institute) have been examining old images of the Jovian moon taken by the Voyager spacecraft back in the 1970s, along with later […]

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