Astronomy Picture of the Day -- Io: Moon Over Jupiter

NASA ^ | April 08, 2012 | (see photo credit)

[SunkenCiv]

Explanation: How big is Jupiter's moon Io? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite. Gliding past Jupiter at the turn of the millennium, the Cassini spacecraft captured this awe inspiring view of active Io with the largest gas giant as a backdrop, offering a stunning demonstration of the ruling planet's relative size. Although in the above picture Io appears to be located just in front of the swirling Jovian clouds, Io hurtles around its orbit once every 42 hours at a distance of 420,000 kilometers or so from the center of Jupiter. That puts Io nearly 350,000 kilometers above Jupiter's cloud tops, roughly equivalent to the distance between Earth and Moon. The Cassini spacecraft itself was about 10 million kilometers from Jupiter when recording the image data.

[SunkenCiv]

[Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA]

[SunkenCiv]

And, a sidebar:

• Jupiter is melting, scientists say

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[Beowulf9]

Lovely.

[Karliner]

all sulfuric acid ain’t it? Pretty but thank God it’s far away.

[dr_lew]

The most forbidding feature of Jupiter is it’s surface gravity of 2.5 g . You could live in a space station in orbit around the planet ( assuming you could deal with the radiation belts,) but any kind of habitat floating in the atmosphere is out of the question.

[haroldeveryman]

Volcanoes release sulfur and sulfur oxide, which fall back down to the surface. Sulfur oxide condenses too because of the low surface temperature.

[left that other site]

I don’t know...It has been looking pretty healthy in the night sky lately! :-)

[bigheadfred]

Page link to PDF

http://commons.wikimedia.org/wiki/File:Io_geological_map_sim3168_sheet.pdf

Direct link to PDF

http://upload.wikimedia.org/wikipedia/commons/9/9f/Io_geological_map_sim3168_sheet.pdf

[SuziQ]

Jupiter is melting, scientists say

Darn SUVs!

[Roccus]

I’ll never forget the feeling I got when I first “discovered” the dancing, Jovian moons in my first telescope.

[SunkenCiv]

Same here.