Outer Solar System

Pluto as ‘Planet’

September 21, 2015

I have never been exactly indignant about the demotion of Pluto to ‘dwarf planet’ status but I do think it’s curious and in at least one respect too arbitrary for my taste. I’ll buy the idea that a planet needs to be round because of its own gravity, and I’ll sign off on the notion […]

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Enceladus: A Global Ocean

September 16, 2015

Seven years worth of Cassini images of Enceladus have told us what many have long suspected: The intriguing moon does indeed have a subsurface ocean. Not that the presence of water on Enceladus comes as a surprise: The south polar region in the area of the famous ‘tiger stripes’ has long been known to be […]

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Pluto/Charon: Complexities Abound

September 14, 2015

Given the flow of new imagery from New Horizons, I began to realize that mission data were changing my prose. To be sure, I still lean to describing the system as Pluto/Charon, because given the relative size of the two bodies, this really seems like a binary object to me. I tend to call it […]

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New Horizons: River of Data Commences

September 8, 2015

Hard to believe it’s been 55 days since the New Horizons flyby. When the event occurred, I was in my daughter’s comfortable beach house working at a table in the living room, a laptop in front of me monitoring numerous feeds. My grandson, sitting to my right with his machine, was tracking social media on […]

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Equinox at Saturn: Puzzling Out the A Ring

September 3, 2015

I’m really going to miss Cassini when it takes its plunge into Saturn’s atmosphere in 2017. Having an orbiter in the outer system means that periodically we’ve been handed spectacular imagery and vast amounts of data for present and future analysis. Each new encounter now, such as the recent one with Dione, is a poignant […]

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Hitchhiker to the Outer System

September 2, 2015

At the Jet Propulsion Laboratory in Pasadena, Masahiro Ono has been using supercomputer simulations to model a new way of moving between small bodies in the Solar System. We’ve had a demonstration in the last few years of what ion propulsion can do to enable orbital operations at one asteroid (Vesta) followed by a journey […]

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A KBO Target for New Horizons

August 31, 2015

What we’ll eventually want is a good name. 2014 MU69 is the current designation for the Kuiper Belt Object now selected as the next destination for New Horizons, one of two identified as possibilities, and the one the New Horizons team itself recommended. Thus we have a target — a billion and a half kilometers […]

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Back to the Ice Giants?

August 27, 2015

As data return from New Horizons continues, we can hope that an encounter with a Kuiper Belt Object is still in its future. But such an encounter will, like the flyby of Pluto/Charon itself, be a fleeting event past an object at huge distance. Our next chance to study a KBO might take place a […]

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Sharper Views of Ceres

August 26, 2015

The mapping of Ceres continues at a brisk pace. The Dawn spacecraft is now operating at 1470 kilometers from the surface, taking eleven days to capture and return images of the entire surface. As this JPL news release points out, each eleven day cycle consists of fourteen orbits, so we’re accumulating views of this formerly […]

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Dione: The Last Close Flyby

August 18, 2015

We’re in the immediate aftermath of Cassini’s August 17 flyby of Saturn’s moon Dione. The raw image below gives us not just Dione but a bit of Saturn’s rings in the distance. As always, we’ll have better images than these first, unprocessed arrivals, but let’s use this new one to underscore the fact that this […]

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