Tag Archives: Galileo

Europa water plume detected in old Galileo data

Using old Galileo data and new techniques of analysis scientists have uncovered a water plume on Europa that the spacecraft flew through in 1997.

Over the course of 5 minutes, spikes the spacecraft recorded with its magnetic and plasma sensors reflected the alterations that a veil of ejected water, from one or many vents, could cause in a region matching the telescope observations, they report today in Nature Astronomy. This indicates that a region of the moon potentially 1000 kilometers long could host such activity, though it is impossible to say whether this is a single plume or many, like the complex system of fractures and vents seen on Enceladus. Indeed, on its own, this evidence was too weak to tie to erupting water in a 2001 study describing it, the authors add, but it fits well with the Hubble and modeled evidence.

As indicated by the quote above, the result has a lot of uncertainty.

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Scientists catch a big volcano eruption on Io

Scientists reviewing twenty year old data from the Galileo orbiter that studied Jupiter and its moons in the 1990s have identified the most intense volcanic eruption yet found on Io.

While looking through the NIMS temperature data, Davies and his colleagues spotted a brief but intense moment of high temperatures that cooled oddly quickly. This signal showed up as a spike in heat from a region in the southern hemisphere called Marduk Fluctus. First, the researchers saw a heat signal jump to 4–10 times higher than background, or relatively normal, levels. Then just a minute later, the signal dropped about 20%. Another minute later, the signal dropped another 75%. Twenty-three minutes later, the signal had plummeted to the equivalent of the background levels.

This signature resembled nothing Davies had seen before from Io. The lava flows and lava lakes are familiar: Their heat signals peter out slowly because as the surface of a lava flow cools, it creates a protective barrier of solid rock over a mushy, molten inside. Heat from magma underneath conducts through this newly formed crust and radiates from Io’s surface as it cools, which can take quite a long time.

This new heat signature, on the other hand, represents a process never before seen on Io, Davies said: something intense, powerful, and—most important—fast.

There’s only one likely explanation for what the instruments saw, explained Davies, whose volcanic expertise starts here on Earth. Large, violent eruptions like those seen at Stromboli are capable of spewing huge masses of tiny particles into the air, which cool quickly.

The article makes it sound like we’ve never seen this kind of eruption on Io before, which isn’t really true. Such eruptions have been imaged, but this is the first time that infrared data of their temperature spike was captured, thus confirming its nature.

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Europe’s continuing problems with Galileo GPS

A look at this week’s failed Soyuz launch and the continuing problems Europe has had building its Galileo GPS satellite constellation.

The program has had a series of problems and failures, which this most recent launch only helps highlight.

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Arianespace and ESA sign contract for three launches

Arianespace and the European Space Agency (ESA) signed a contract on Thursday for the Ariane 5 rocket to launch 12 more of Europe’s Galileo GPS satellites on three launches.

This contract is a perfect example of European pork. Europe’s Galileo system might provide competition to the U.S. GPS and Russian Glonass systems, but I am not sure what additional capabilities it provides that will convince GPS users to switch to it. Instead, building it provides European jobs, while using the Ariane 5 rocket to launch it gives that increasingly uncompetitive rocket some work to do. In fact, this situation really reminds me of the U.S. launch market in the 1990s, when Boeing and Lockheed Martin decided that, rather than compete with Russia and ESA for the launch market, they instead decided to rely entirely on U.S. government contracts, since those contracts didn’t really demand that they reduce their costs significantly to compete.

Europe now appears to be heading down that same road.

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Eddi Reader – Galileo

An evening pause:

Galileo fell in love as a Galilean boy
And he wondered what in heaven, who’d invented such a joy.
But the question got the better of his scientific mind
And to his blind and dying day
He’d look up high and love and sighed and sometimes cried,
Who puts the rainbows in the sky?
Who lights the stars in the night?
Who dreamt up someone so divine?
Someone like you and made them mine?

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