Does life lurk beneath Europa’s icy shell? Our quest to find life beyond Earth might not lead us to some distant exoplanet. It could be much closer to home. Scientists believe a salty ocean swirls below the frigid surface of Jupiter’s moon.
NASA has a plan to explore Europa and find out if it’s habitable. This week, that plan got a name – Europa Clipper. It was a name tossed around during the mission’s conceptual phase, and NASA went ahead and made it permanent. It’s named after clipper ships that quickly carried trade goods across the world’s oceans in the 19th century.
It’s a perfect name for a mission that will see a spacecraft sail quickly past Europa up to 45 times.
Did You Know: Despite temperatures of -260 degrees Fahrenheit on the surface, Europa’s interior is believed to be made up of an ocean twice as big as the oceans on Earth. How? Tidal flexing. Because Europa’s orbit is elliptical, Jupiter’s gravitational tug varies causing a flexing effect. This warms the interior and forms what scientists believe is a huge ocean.
The ocean scientists believe rests below Europa’s surface. Credit: NASA
Europa Clipper orbits Jupiter, not Europa
Much like the recent arrival of the Juno spacecraft, the Europa Clipper has to operate in an extreme radiation environment. That means quick flybys to avoid prolonged exposure to high radiation around Europa and Jupiter. NASA wants to get in between 40 and 45 flybys during the primary mission. If the spacecraft can handle it, we could see more.
“During each orbit, the spacecraft spends only a short time within the challenging radiation environment near Europa. It speeds past, gathers a huge amount of science data, then sails on out of there,” said Robert Pappalardo, Europa Clipper project scientist.
No two flybys will be the same. Some will skim just 16 miles above the surface, while others pull back 1,700 miles away. Plus, the flybys will come at different angles. Here’s how the orbits looked as the team was putting the mission together in its conceptual phase.
Europa Clipper might not answer the life question
We don’t know how life will look on another world. We know how it works on Earth, but Europa? We’re not sure. What the Europa Clipper can tell us is if the right conditions are here for life to exist. Does Europa’s interior ocean mimic conditions we see in the depths of our own?
A magnetometer will be used to probe the depths of Europa’s assumed ocean. Radar and heat detectors will closely examine the structure of the ice to see how it may help in providing organics to the ocean.
Another instrument, a UV spectrometer, will keep a watchful eye out for plumes erupting from the surface ice. If discovered, mission controllers will plan future flybys to soar right over them. The Europa Clipper’s mass spectrometer could reveal the presence of hydrothermal vents on the seafloor by determining the makeup of the vapor from the plumes.
No lander on this mission
There were rumblings of a potential lander, but the Europa Clipper will only be an orbiter. NASA is still looking into the idea about a potential Europa lander. Last month, a report on the science value of a lander was delivered to NASA. The space agency is looking for feedback from the science community about the study.
The primary objective would be to search for evidence of life on Europa and determine its habitability.
Studies like this don’t mean the mission is happening. NASA uses them to understand what challenges a mission will face, how feasible it is, and what science value it brings to the table. Two upcoming town hall meetings are scheduled to talk about the study. The first will be held on March 19 at the 2017 Lunar and Planetary Science Conference (LPSC) at The Woodlands, Texas. The other on April 23 at the Astrobiology Science Conference (AbSciCon) in Mesa, Arizona.
What would potential life look like on Europa?
That’s the big question, isn’t it? We can make one assumption. Sunlight doesn’t play a role in it. Europa already receives just a tiny bit of sunlight. Throw in a thick icy shell above it, and the ocean sits in permanent darkness. Life, if it exists, would perhaps look like it does in the deep depths of Earth’s oceans. An ecosystem supported by hydrothermal vents.
Or, it might not exist at all. Maybe the water’s makeup doesn’t allow for even the simplest life to grab hold. Maybe it’s not as simple as ‘where there is water, there is life.’
But the possibility (and implications) are too high not to look. And if the Europa Clipper finds the right conditions, it’s feasible these same conditions exist on other moons where oceans are believed to exist. Enceladus immediately jumps out since we’ve already seen water vapor plumes coming from it.
But when will Europa Clipper reach Jupiter?
This is the only downside to being a space fan. Things move too slow. Right now, NASA is hoping to launch the mission in the early 2020s. Add in a few years for transit time, and we’re looking at mid-to-late 2020s before it gets there. Then, there’s the mission timeline with two weeks or more between flybys.
It will be a long wait, but the data gathered by the spacecraft could be game-changing.