Subsurface oceans everywhere and the possible pervasiveness of life

Well, it now looks like Ganymede, one of Jupiter’s moons, has a subsurface ocean.

Ganymede’s great distinction among moons – apart from its size – is that it has its own magnetic field.

Hubble has managed to track that field’s behaviour by watching how it draws in and excites space particles, generating a glow of ultraviolet light around the satellite’s north and south poles.

But this intrinsic magnetic field also interweaves with Jupiter’s, and the aurora “rock” back and forth as a result of the interplay.

It is by modelling the expected rocking against what is observed by Hubble that scientists can infer something about the internal structure of the moon. And they now say a salty ocean at depth is the best explanation for what they see.

It seems like these subsurface oceans are all over the place in the outer solar system.

Ganymede is just one of a large list of objects in the Solar System now thought to hide an ocean deep below the surface. These include the dwarf planets Pluto and Ceres; other Jupiter moons – Europa and Calisto; Saturn’s moons Enceladus, Titan and Mimas; and possibly Neptune’s moon, Triton.

“The Solar System is now looking like a pretty soggy place,” joked Jim Green, the US space agency’s director of planetary science.

In some ways, this shouldn’t be too surprising.  In the outer solar system, where temperatures are typically far below -100 °C, ice is basically a type of rock, and water is essentially a molten form of that ice rock, in the same way as magma is to the rock we’re familiar with.

But all of these subsurface oceans give us lots of environments that have the potential to host life similar to how we understand it, in that they have liquid water coupled with an energy source (whatever is keeping the water warm enough to be a liquid).  One mystery of the origin of life is how likely that origin is to occur.  If it’s more likely, then there’s more life in universe.

If, despite lots of places where conditions are favorable for it, we find don’t find life anywhere else in the solar system, then that may indicate that life is fairly rare in the universe.  On the other hand, if we do find it, and we can establish that it’s not somehow related to life on Earth, then it seems like it indicate that life is pervasive throughout the universe.

How could life on Ganymede be related to life on Earth?  It seems farfetched, but in an ancient solar system with asteroid strikes flinging debris into space, it’s very possible that microbes could be exchanged between planets.  Martian rock has been detected in some of the meteorites that have crashed to Earth.  That said, the outer solar system is much farther away, and any transfer between here and there seems much more tenuous.

None of this would have too much bearing on how prevalent intelligent life is in the universe, except perhaps to set a possible upper bound on it.  Life existed on the Earth for billions of years before intelligence evolved, with intelligent tool using species being very rare.  Even if life is pervasive in the universe, intelligent life is likely still exceedingly rare.

It’s time to look for life in Europa’s ocean

Lee Billings has a fascinating article up at Aeon asking why we continue to send missions to Mars when the best chance of life existing today is in Europa’s underground ocean.

If Europa is alive, if some biology dwells within those dark waters, the implications would be even more staggering than finding life on Mars. Our gaze would turn to Jupiter’s Ganymede next, and to Callisto, along with Saturn’s Titan and Enceladus, and perhaps even the dwarf planets such as Ceres and Pluto, all of which also likely harbour substantial subsurface reservoirs, heated through some combination of tides and radioactive decay.

And if water and life could exist there, why not in the hearts of large comets, before the Sun’s planets and moons even finished forming? Our solar system might have brimmed with hidden life for nearly as long as the Sun has shined, and ice-roofed worlds might be the default abodes for biology in the Universe. Life within a roofed world could proceed swimmingly against any number of otherwise-fatal cosmic calamities, whether being slingshotted into the interstellar dark as a rogue planet, or being bathed in hard radiation from a nearby supernova or burping black hole. We could then guess why, like our solar system, the Universe at large looks so desolate to us. In this scenario, most life, even if it had eyes to see, would never glimpse sky, stars, light, or fire, and would have scant hope of ever reaching what lies above and beyond its icy shell.

via It’s time to look for life in Europa’s ocean – Lee Billings – Aeon.

I’ve highlighted what I considered to be the most mind blowing part of the article above, but I recommend the whole piece.

As Billings admits, the cost of exploring Europa is much higher than Mars.  And Europa is a far harsher environment for us.  But the possibility of life is much stronger.  And the passage above makes me wonder if we shouldn’t be taking a closer looks at other places such as the large comets he mentions.  Of course, all of this takes money.

The really mind blowing part though is the possibility that life might be much more prevalent in those types of environments.  We tend to assume that Earth is typical, but there’s nothing to indicate that it is typical for life other than the Copernican principle, which although history has repeatedly validated it, it remains only a principal; past performance is no guarantee of future performance.

NASA planning a robotic mission to Europa

Related to my last post on Europa Report, a movie I discovered when I read these articles earlier today, and also in the category of things I somehow missed, NASA is planning a robotic mission to Europa.  This is exciting since, as I noted in the movie review, Europa’s underground ocean makes it currently the most likely candidate for extraterrestrial life in the solar system.

NASA wants to visit Jupiter’s moon Europa. Why’s that exciting? In a word: Water. As this visualization shows, the icy moon may look tiny next to our own planet, but it’s got 2- to 3-times as much H2O as we have here on Earth. That “little” moon is packing quite the store of water — and with it, scientists think, a significant chance of harboring life.

via This image is why everyone’s so excited about a NASA mission to Europa.

It looks like it’s finally going to happen, an actual mission to Jupiter’s icy moon Europa — one of the the solar system’s best candidates for hosting alien life.

Yesterday, NASA announced an injection of $17.5 billion from the federal government (down by $1.2 billion from its 2010 peak). Of this, $15 million will be allocated for “pre-formulation” work on a mission to Europa, with plans to make detailed observations from orbit and possibly sample its interior oceans with a robotic probe. Mission details are sparse, but if all goes well, it could be launched by 2025 and arriving in the early 2030s.

via NASA plans a robotic mission to search for life on Europa.

Europa Report, a review

Europa_Report_Official_PosterSomehow I completely missed the release of this movie.  It seems to represent the beginning of something I’ve hoped to see for a while: small independent productions that make use of the lowering cost of CG technology to make narrow genre films.  Most film science fiction is, unfortunately, garbage scientifically.  The cost and risk of making these films usually makes producers too skittish to take the chance of making a film that is accurate, instead taking the low road of confirming the audience’s common misconceptions.

But this film has a remarkable degree of scientific accuracy.  It does make some compromises, but they are the type of compromises that any but the highest cost productions couldn’t avoid, such as having the characters move around while on Europa as though the gravity was the same as Earth’s.

The film is about a manned mission to Europa, one of Jupiter’s moons, that is famous for possibly having an underground ocean under its icy surface.  Everywhere we have water on Earth, we have life.  Europa, as the only location of an ocean in the solar system, may be the likeliest candidate for extraterrestrial life in the solar system.

The story is told in the found film format, where we see the mission as it progresses from footage found after the event.  For this reason, I don’t think it’s much of a spoiler for me to say that this isn’t a happy tale, but a thriller with the intensity building as the movie progresses.  All the action is seen from cameras inside the craft, mounted outside the hull, or on the helmets of spacesuits.

One thing I was very happy to see is that the film mostly avoids the trope of astronauts going crazy on the mission.  You definitely can feel the stress that the crew is under, particularly as the situation gets progressively more desperate.  Yet, the characters generally remain professional and do their job to the limits of their ability, and I found that immensely refreshing.

The story is told in a nonlinear fashion, with the action switching between various stages of the mission.  We watch as the mission loses communication with Earth, attempts to reestablish it, fails, and continues with the mission anyway.  We see the characters on the surface of Europa working to learn as much as they can to fulfill the purpose of their mission: to see if there is life on Europa.

This is a very well made production, with a gripping story, and a strong adherence to the science and technology of how such a mission would likely work.  The footage showing Jupiter and Europa is taken from NASA videos and pictures, giving the film an authentic feel.

I hope we see a lot more of these kinds of small indie films.  I rate it five stars.  It’s available on Netflix and for digital rent or purchase on Amazon.  If you enjoy science fiction thrillers, particularly when the science is done right, I highly recommend this film.