As it turns out, you can literally scratch the surface of Europe to find life.
In a paper published today in Nature Astronomy a group of JPL researchers claim that even areas are exposed. Under the hardest radiations, you must not exceed 20 inches or anything less than eight inches in the icy Dig surface to find clues to life on Jupiter's moon Europa.
Europe is one of Jupiter's four great moons. It is known to have an ocean below and is considered one of the best places to have life outside of our solar system. But the moon is also exposed to enormous amounts of Jupiter's intense radiation that extends beyond the planet. While life would be well protected under Europe's thick ice cover, the researchers wanted to know if it could still find evidence of life on the surface or if it would be destroyed by radiation.
"We have known for a long time that the surface radiation of Europe is really dominant on the surface, as in a particle accelerator," says Tom Nordheim, a research laboratory of the Jet Propulsion Laboratory and lead author of the newspaper.
Here's a rough picture of vital signs coming from the ocean below: Europe is known for having some active "feathers", something like an ice geyser spraying ocean water a few miles into space before it starts again the surface falls. Like our own, this ocean water can be filled with microbes and other chemicals that are directly related to life. The microbial life will not survive the short trip. But by-products of life could. The study wanted to know how much of these by-products would survive and whether they could be detected by a future NASA mission.
The study examined where Jupiter's radiation hits hardest. In these areas, the surface is too strongly hit by radiation, so that some amino acids ̵
"Even in the harshest radiation zones, one only has to scratch the surface to find material that has not been destroyed." Nordheim says:
This has a big impact on NASA's future plans in Europe. In 2022, NASA will launch Europa Clipper in the direction of the Jupiter system. In order to protect the probe from the radiation it would experience if it were to stay in European orbit, the Clipper will actually enter orbit around Jupiter and crash through Europe for several close fly-bys. Congressional appropriation requires that a lander be part of the mission, although NASA focuses largely on orbiter design. This study shows that finding biosignatures with a lander is no big task – whether in 2022 or a Europe mission across the board.
Preliminary plans for the lander indicate that he could drill 10 centimeters in Europe. but these plans were released last year and are subject to change.
"This means we can drill and we can drill at marginal shallow depths," says Amy Warren, a SETI Institute scientist who studies the habitability of planets. "This is really a foretaste of being able to look for habitable environments." (19659002) Although many people would like to explore Europe in person, robotic research is currently our best option. While radiation is more severe in some areas of Europe than in other areas, total radiation would be fatal to humans, no matter where you land. "It would certainly be much more useful to be outside of these radiation zones, but I do not think that standing on Europe anywhere is a pleasant environment for humans," says Warren.
The next steps for the team include a deeper approach See how Europe's magnetic field and ionosphere interact and possibly oppose Jupiter's radiation belts. Data on Europe are somewhat hampered by the failure of the high-gain antenna aboard NASA's Galileo spacecraft circling Jupiter in the 1990s and 2000s, but Nordheim says there are enough to build good models for Europe. If these models find that Europe's magnetic field protects the moon from radiation, it could paint an even brighter picture for finding biosignatures on the moon, and perhaps even find ways in which the search could be done by an orbiter.
No matter how future studies poke out, finding life in the solar system is still a deep, difficult question. Fortunately, today's study shows that exobiologists may not have to dig as deeply as they thought to respond.