“So, where are they?” is the genesis of the famous Fermi Paradox, which is the contradiction between high estimates of intelligent life in the universe and the fact that — so far — there is no physical evidence that aliens have paid us a visit, nor is there any sign of intelligence that we can detect. Physicist Enrico Fermi asked that question nearly 60 years ago and since then, what has become known as the Fermi-Hart Paradox has been a useful starting point for scientific studies about the possibility of alien life in the universe.
The problem is, the universe is 14 billion years old and even if there were just a few intelligent spacefaring civilizations, the entire universe could have been colonized in a few tens of millions of years. There are no good scientific answers largely because we simply don’t have much information.
That doesn’t prevent scientists from speculating. Perhaps life itself is abundant in the universe but intelligent life capable of creating industrialized civilizations that can build rockets to the stars are incredibly rare. Carl Sagan posited the notion that most intelligent civilizations might blow themselves up or poison themselves before they reach maturity and are able to plan interstellar trips.
Certainly, many intelligent civilizations are wiped out by comets and asteroids. Others fry from a nearby gamma ray burst or a black hole mosies into the neighborhood and eats everything in sight.
All of this gives a special impetus to the search for alien life. What is it? Would we be able to recognize it if we saw it? Is it sitting right in front of us but we’re unable to detect it?
That last question is one that NASA may next try to answer in the next decade. In the agency’s budget request for FY 2016, $30 million has been allocated for a mission to Jupiter’s icy moon Europa. Europa is a prime candidate to harbor life because all signs point to a huge ocean of water below the surface ice. All across the moon’s surface are cracks and crevices where that water has broken the surface. There may be volcanoes on the floor of Europa’s oceans that spew hot gasses, heating the water, melting the icy crust covering the ocean, and pushing liquid water on to the surface.
It doesn’t exist long as a liquid due to the extreme cold and non existent atmosphere. But on the ocean’s floor, if volcanoes are responsible for the heat, life could have taken hold. Earth has similar volcanic vents on the floor of our oceans that teem with life. It’s a sexy, tantalizing question and scientists are anxious to go there and see for ourselves.
“From an astrobiology perspective, Europa really brings together the three keystones for habitability,” Kevin Hand, the deputy chief scientist of solar system exploration at NASA’s Jet Propulsion Laboratory, tells Popular Science. “And that is of liquid water, access to the elements needed to build life, and potentially the energy needed to power life.”
NASA has been contemplating a trip to Europa for a couple of years, and Congress recently gave the project $100 million for 2015. While the White House proposal only allots $30 million, the fact that it’s coming from the president is important. NASA is an executive branch agency, in need of White House support, and the administration’s new budget “supports the formulation and development of a Europa Mission.” That means NASA engineers can finally put their planning into action.
“They want us to move into the next phase of the mission,” says Robert Pappalardo, the Europa Clipper pre-project scientist at JPL. “So we’re moving to Phase A, where you become a real mission, not just a concept.”
Europa is a bit of an anomaly within our solar system. The moon’s outer layer consists of an icy sheet, somewhere between 1 mile and 18 miles thick (the scientific community is divided on its depth). Due to the ice’s smooth surface and lack of impact craters, researchers believe that this layer is relatively young and active, meaning something—such as an icy, volcanic flow underneath—is constantly renewing the ice and erasing past imperfections.
This has led many experts to support the theory that there’s an ocean underneath the icy crust. The idea was further solidified in 1995 during NASA’s Galileo mission, in which a probe entered orbit around Jupiter. As it passed by the moons, the Galileo spacecraft found that Jupiter’s magnetic field was disrupted in the area around Europa. The disruption indicates that an electrically conductive fluid beneath the moon’s surface is inducing a special kind of magnetic field around the satellite. And given Europa’s icy outer shell, that substance is most likely water.
There are a few ideas on how to penetrate the 1-18 mile ice crust and get to the ocean. Perhaps something as simple as a heated wire unspooled from a lander with a camera and some basic sensors. But since Europa’s oceans might be 100 miles deep — or more — it doesn’t seem practical at this point.
Another idea involves some kind of drilling machine capable of both smashing through the ice and then maneuvering in the ocean. How the machine maintains contact with the lander would be a problem no one has figured out how to overcome.
One thing is sure; the mission to Europa won’t be cheap. In a time of severe budget restraints, it might not be wise or practicable for NASA to designate a mission to Europa as a priority. The moon and Mars beckon us and those missions will also be very expensive, taking most of the agency’s budget over the next decade.
But who knows? At the very least, NASA will study the parameters of a mission to Europa and perhaps they can come up with a solution that isn’t as expensive as it seems.
At least they’re going to get the opportunity to try.