All these worlds etc etc

May 24, 2016 10:59 AM

Europa's Ocean May Have An Earthlike Chemical Balance. A new NASA study modeling conditions in the ocean of Jupiter's moon Europa suggests that the necessary balance of chemical energy for life could exist there, even if the moon lacks volcanic hydrothermal activity.
posted by showbiz_liz (7 comments total)

I was always curious how Arthur C. Clarke came to focus on Europa in his work long before other scientists went out and explored it. Was it just a lucky guess on his part, or was there some speculation already happening around that time?
posted by a lungful of dragon at 12:49 PM on May 24, 2016 [2 favorites]

I'm having a surprisingly hard time figuring out WHEN we first got our info about Europa, but it's been the strongest candidate for extraterrestrial life in the solar system for a while now, because it almost certainly has liquid water - and I believe they first figured out that it was covered in ice because it's the smoothest object in the solar system, then they figured out that it might have a liquid core afterward, possibly making inferences from the fact that it's covered in cracks which could be the result of tidal forces.
posted by showbiz_liz at 12:59 PM on May 24, 2016 [2 favorites]

Aha! Seems we got our first hints in 1979, and the movie 2010 didn't come out until 1984.

In the 1960s, ground-based telescope observations determined that Europa's surface composition is mostly water ice, as are most other solid bodies of the outer solar system.

The Pioneer 10 and 11 spacecraft flew by Jupiter in the early 1970s, but the first spacecraft to image the surfaces of Jupiter's moons in significant detail were the Voyager 1 and 2 spacecraft. Voyager 1's closest approach to Jupiter occurred in March 1979, with Voyager 2 following in July of the same year. The best imaging resolution of the Voyagers was limited to just over 1 mile (2 kilometers) per pixel. These images revealed a surface brighter than that of Earth's moon, crisscrossed with numerous bands and ridges, and with a surprising lack of large impact craters, tall cliffs or mountains (in other words, a very smooth surface, relative to the other icy moons).
posted by showbiz_liz at 1:04 PM on May 24, 2016 [3 favorites]

Fascinating:

"The oxidants from the ice are like the positive terminal of a battery, and the chemicals from the seafloor, called reductants, are like the negative terminal. Whether or not life and biological processes complete the circuit is part of what motivates our exploration of Europa," said Kevin Hand, a planetary scientist at JPL who co-authored the study.

Life as part of a giant circuit. I had no idea that reactions between seawater and rock (olivine in particular) generate the conditions necessary for life. Here's the paper, but it's probably paywalled.
posted by Existential Dread at 2:49 PM on May 24, 2016 [3 favorites]

Clarke was tight with a lot of people in the astrophysical community, and he knew ahead of the rest of us that they were starting to suspect Europa might harbor life. Of course, Saturn's moon Enceladus is an even better bet in some ways, but we didn't know about it until this century. And Titan's lakes were considered a kind of far-out possibility before Cassini verified that they really exist.
posted by Bringer Tom at 4:41 PM on May 24, 2016 [2 favorites]

It's a shame that Juno (due to arrive at Jupiter in a couple of months is just (hah, just) going to observe the planet.

There is a planned Europa mission in the works, but even if it gets approval it won't get going for a decade and will, of course, attempt no landing there.
posted by Devonian at 4:52 PM on May 24, 2016 [6 favorites]

TOYNBEE IDEA
IN 2001
RESSURECT DEAD
ON PLANET JUPITER
('S MOON EUROPA)
posted by Fig at 3:10 AM on May 25, 2016 [1 favorite]