Aliens of the Deep
THE CONNECTION BETWEEN SEA AND SPACE
Scientists at JPL and NASA have embraced the cutting-edge concept explored in “Aliens of the Deep,” that an expedition to study life on the ocean floor can teach us about an expedition to study life in the furthest reaches of the solar system.
Arthur Lonne Lane is a principal scientist at JPL now in his 38th year with the organization.
“Interest started in this about seven years ago,” notes Lane.
“I was part of the Jupiter mission, both with Voyager and with Galileo. It turns out that ice has unique chemistries on Jupiter’s moons; with the volcanoes on the moon Io spewing sulphur out to the other moons, there’s a very interesting set of chemical reactions. So I became interested in ice.
“With another scientist at JPL, we started looking at a freshwater lake buried two-and-ahalf miles under the ice in Antarctica. In ancient history, we think, it was part of Australia; it had a temperate climate. It was lush. It was green. There were animals. But when it broke apart, the climate changed and Antarctica froze pretty quickly. “
So here’s the question: You have a body of water that probably had life going on, frozen over for a long period of time by an icecap, sealed. What’s going on down there? Can life exist in this kind of environment? How could you measure anything in this body of water that’s been sealed so longis it sterile?
“And while we were looking at this lake, we had parallel results from Voyager and Galileo: the missions pointed to a very large ocean under the ice on Europa. Is there a parallel? Could there be life under the ice?
“And then came the realization that life did not require light. One of the paradigms when I went to school was that life had to have light. No. That’s wrong. We’ve proven that.” In fact, life exists on the ocean floor, several miles down, where sunlight cannot reach. Life can exist at such depths due to hydrothermal vents, where volcanic activity at the ocean floor releases minerals into the water. Kevin Hand, a planetary scientist and astrobiologist who joined Cameron on the expedition, explains that life in these harsh conditions is made possible by the energy-rich chemistry of the superheated mineral-charged water.
“There are microorganisms that live in these extremely hot and toxic environments that metabolize chemicals in the vent water and, in so doing, fix carbon in such a way that it becomes available to the larger creatures,” Hand explains. In simpler terms, the microbes eat what the larger organisms cannot and in the process create sugars and other nutrients from which the shrimp and the mussels and the tube worms can live.
Lane continues, “So here you have parallels among the deep ocean, a lake in Antarctica, and a moon of Jupiter. What are the common points? How do you explore them? “I’ve been a scientist for almost 40 years, so I’m not going to be around for the Europa exploration. That’s another 20 years down the road, perhaps,” Lane concludes.
“But the last part of my career is about setting in place the concept, the steps by which you get there and testing out these ideas, so that people can easily move forward.”