Outer Solar System

Atmospheric Collapse on Io

August 9, 2016

I suspect most scientists would like to have a moment like the one Stanton Peale, Patrick Cassen and Ray Reynolds experienced when Voyager flew past Io in 1979. How many of us get to see a major idea vindicated in such short order? It was on March 5 that Voyager 1 passed within 22,000 kilometers […]

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Jupiter’s Great Red Spot as Heat Source

July 27, 2016

Speculating about what an advanced extraterrestrial civilization might do has kept us occupied for the last two days, with gas giants like Jupiter the primary topic of conversation. We don’t know if it’s possible to ignite a gas giant to provide new sources of energy. But with Juno getting ready to measure Jupiter’s aurorae, we’re […]

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A New Dwarf Planet (and its Implications)

July 15, 2016

A dwarf planet designated 2015 RR245 (and now in search of a name) has been found in an orbit that takes it out to at least 120 AU. It’s a discovery made by the Outer Solar System Origins Survey (OSSOS), an international collaboration focused on the Solar System beyond Neptune. The goal is to test […]

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Updates from Jupiter and Ceres

July 14, 2016

We don’t have high-resolution pictures of Jupiter from the Juno mission yet, but we do have JunoCam in operation. It’s a color camera working in visible light that has returned data following the spacecraft’s arrival at Jupiter on July 4. This JPL news release tells us that JunoCam was folded into the mission as part […]

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Prebiotic Chemistry on Titan?

July 7, 2016

If you’re looking for liquid water on Titan, prepare to go deep, perhaps as much as 100 kilometers below the Saturnian moon’s crust, which is itself made of ice. When it comes to exoplanets, we always talk about the habitable zone as a place where liquid water could exist on the surface. Titan clearly fails […]

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Operations Throughout the Solar System

July 6, 2016

A reminder of how challenging it is to operate with solar power beyond the inner system is the fact that Juno carries 18,698 individual solar cells. Because it is five times further from the Sun than the Earth, the sunlight that reaches Juno is 25 times less powerful, a reflection of the fact that the […]

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Arrival: Juno in Orbit

July 5, 2016

People in the space business always joke about the stress levels at any launch, but if you’re keeping tabs on a billion dollar spacecraft like Juno, I’d say the arrival can create just as many, if not more, gray hairs. Plenty of people are breathing easier this morning after Juno’s successful 35-minute engine burn and […]

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Revisiting Enceladus’ Ocean

June 23, 2016

As we saw yesterday, there is a case to be made that the ocean beneath Pluto’s ice is still liquid, based on phase changes in ice under varying pressures and temperatures. Today we turn to another world with interesting oceanic possibilities, Enceladus. Here the data are problematic and contradictory. Flybys by the Cassini Saturn orbiter […]

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Pluto: Evidence for a Liquid Internal Ocean

June 22, 2016

What accounts for Pluto’s interesting landscape? As we accumulate more and more data from New Horizons, we’re seeing a wide range of geologic activity on the surface, most of it involving such volatile ices as nitrogen, carbon dioxide and methane. But look at the troughs and scarps — some of them hundreds of kilometers long […]

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Asteroids as Spacecraft

June 14, 2016

Rama is a name that resonates with science fiction fans who remember Arthur C. Clarke’s wonderful Rendezvous with Rama (1973). The novel depicts a 50-kilometer starship that enters the Solar System and is intercepted by a human crew, finding remarkable and enigmatic things that I will leave undescribed for the pleasure of those who haven’t […]

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