Many people don’t realize that Jupiter’s moon Europa is actually covered in a global-wide ocean of liquid water. It’s an exciting prospect for humans who wish to answer the profoundly significant question “has life ever originated in other parts of the universe?”
Follow the Water
NASA’s mantra for finding life on other worlds has been “follow the water.” That’s because life as we know it depends on water to survive. Finding water on the surface of other planets and moons in our solar system has been nearly impossible because most of the time, the low atmospheric pressures on other worlds combined with extremely low temperatures prohibit it.
For H2O to exist in liquid form, there has to be enough atmospheric pressure to hold it together, and Earth is the only place we know of where that happens on the surface. On Mars or Europa for example, there just isn’t enough atmospheric pressure to hold water molecules together, so even if the temperatures get high enough for it not to freeze, it basically boils away the minute it reaches the surface.
Living on Thin Ice
The good news is that on Europa, the ice layer which covers its global ocean is so thin, it allows the ice to occasionally crack, briefly exposing its liquid ocean to the surface. This means that future missions searching for life wouldn’t even have to bring substantial drilling equipment to drill through the ice to find it. A rover could travel to a promising location where cracking is likely to open up the ocean to the surface, and samples could be taken right then and there. By not having to develop and send a heavy payload of drilling equipment, an effective mission to search for life on Europa could be done relatively cheaply by NASA standards. We could literally be only a few million dollars away from solving one of the most significant and profound questions in human history, “are we alone in the universe?”
So what could possibly be living down there? Isn’t Europa just too far from the sun to support life? Actually, we already have found a variety of living organisms deep in Earth’s oceans completely removed from any sunlight, that live off of thermal vents at the bottom of the ocean floor. These vents release food and heat which these creatures we call extremophiles live off of. Due to the incredibly powerful gravitational pull from Jupiter, in additional to Europa’s sister moons, Europa experiences significant thermal heat from the constant stretching of its core. How does stretching create heat? For an example of this, just bend a paperclip back and forth and notice how it heats up, and eventually cracks. That’s what’s happening on Europa.
Check It Out
In response to David Anderson’s Articulate Elearning Challenge, I created this little graphic to talk about Europa’s global ocean and what it means to the search for extraterrestrial life. I also wrote, performed, and recorded a David Lynchian “Song for Europa” on my crusty old Mirage keyboard sampler (don’t ya just love that 8-bit sampling rate!). Let me know what you think.