On Friday, February 10, NASA announced that a team of 21 scientists had delivered their first report on a lander mission to explore the possibility of life on Jupiter's icy moon Europa. The NASA-employed Science Definition Team (SDT) recommended that NASA send a probe as soon as 2031, about a decade after an already-planned Europa flyby mission.
The lander will be primarily focused on studying the enormous ocean thought to be hiding deep beneath Europa's surface. In addition to collecting and analysing samples from the ocean that have escaped through cracks in the moon's icy crust, the probe is expected to drill 10cm down. SDT member Jonathan Lunine described the hypothetical mission as a "bug hunt", designed to scope out surface deposits for signs of life far below.
Since early 2016, a NASA-employed Science Definition Team (SDT) of 21 researchers has been crafting a plan to send a robotic probe to Europa, an icy moon of Jupiter, located over 390 million miles from Earth. On February 7, that team delivered their first report to NASA, detailing their recommendations for that future mission, which will search for life by drilling toward the subterranean ocean scientists strongly suspect to exist beneath the icy moon's surface. The team hopes to launch as soon as 2031.
While many are excited about the prospect of finding life on Europa (*raises hand*), there's an important ethical question to consider: Could landing on and drilling into this world actually contaminate it? "It's essential we avoid bringing contaminants from Earth with us," president of extraterrestrial messaging organisation METI International Doug Vackoch told Gizmodo. "There is a raging debate within the planetary protection community about whether any indigenous microbial life on other planets and moons of our solar system has an innate right to exist."
It's a debate that's likely to rage on for years. But Seth Shostak, senior astronomer at the SETI Institute in California, already has some damn interesting thoughts on the matter of planetary protection. Gizmodo caught up with him for more insight into the risks and rewards of drilling and alien hunting on icy Europa.
Gizmodo: Do you think there's a reasonable shot that we might find life on Europa?
Dr Seth Shostak: Well yeah, I do. I don't think there's anything radical in saying that. If you talk to people in the astrobiology business and ask them, "Hey, look, if you wanted to find life in space and you've only got shot at it, where would you look?" And half of them would say Mars -- after all, Mars is everybody's favourite "inhabited" planet.
But the other half might say another world, because there are seven -- at least I count seven -- other worlds in our own solar system where you might find a little bit of biology. I think number two would definitely be Europa, after Mars. In fact, Europa might even beat Mars. I think our little ruddy buddy is maybe not the favourite for everyone.
But the thing is that we've known for a long time that OK, Europa has this icy surface, it's maybe 16km thick and underneath that is an ocean with twice as much water as you have in all the oceans here. But look, maybe it's sterile. Maybe after four billion years nothing interesting has happened there.
Gizmodo: What do you think about the plan to drill a few centimetres into Europa's surface?
Shostak: So the idea [from science fiction] is you send Bruce Willis to Europa with a bunch of roughnecks and they drill down to the ocean and they drop a video camera and a lightbulb and you see what you can find. Uh, that's hard. But people have talked about that for a long time. To [drill] down a little bit is sort of an approximation.
There's a simpler way to do this, which I think might could happen much sooner. Some of the water from underneath that ice actually squeezes through the cracks and makes these kinds of geysers -- this is something that was found in the last year. All you have to do is send an orbiter down to Europa [and scope out the areas where geysers have erupted]. You don't have to land and drill -- that's hard and expensive.
Jupiter's moon Europa is on the shortlist of places we might discover alien life in our solar system. And today, the prospects for finding extraterrestrial microbes on this little ice moon got a lot better, when NASA unveiled new evidence for water geysers near Europa's south pole. The discovery strengthens the case for a geothermally-heated, subsurface ocean.
In a way, Europa is offering up its innards, or at least parts of them. So why not take advantage of that? If it's gonna bring the meal to you, why go to the restaurant?
Gizmodo: The SDT's report says they will try to look for these cracks in the surface and sample the material oozing out. But on the other hand, they recommend drilling 10cm into the surface. If they find there's some success there, this could lead to later missions where a lander could dig even further. Could drilling contaminate Europa?
Shostak: Well, you know, there's always this contamination issue; there's forward contamination and backward contamination. Backward contamination is the Andromeda Strain kind of scenario, where you're bringing something back and everybody gets sick and dies. It's sort of mass pandemic like, reality television or something, and just turns everybody's brains to the consistency of oatmeal.
In this case, I don't know if you'd bring back anything dangerous. (NASA's Europa lander mission, as currently envisioned, will not bring samples back to Earth. It's possible that a future mission could, however.) The forward contamination thing is something that indeed, you know, there's an office at NASA that worries about these kinds of things (Gizmodo has reached out to NASA's department of planetary protection for comment.) But I gotta say, I wouldn't worry too much about it in the case of Europa. People don't worry about it in the case of Mars! We sent all these motorised skateboards to Mars, and you know, they're rolling around the planet and you might think, "Oh my God, those are filled with earthly microbes that will contaminate everything." And it's true, they sterilise them, but you can't really completely sterilise them -- you get rid of 99.999-whatever-per cent.
But in that remaining 0.000-whatever it is, there's still microbes in there. But they land on Mars and of course there's no oxygen, not that it matters to them, but there's also ultraviolet light and it's extremely dry. And it's very very cold, so these guys aren't happy -- they don't go anywhere. Some of the [microbes] might survive in the spacecraft for a little while, but the idea that you're contaminating Mars with these things is pretty extreme, and I think it would be even [more extreme] in the case of Europa -- it only gets four per cent as much sunlight as you would on Earth. It's really cold! These microbes [from Earth] aren't gonna be doing much.
I don't worry much about contamination. The only thing is, if you're gonna drill, you do have to be careful that your experiment can recognise something that you brought with you as a hitchhiker, versus something that's native.
Gizmodo: So in all, do you think the benefits of drilling into Europa outweigh any potential consequences?
Shostak: Oh, yeah, yeah, for sure. I guess what you're really asking there is, "Is the potential for finding life worth the risk to contaminating Europa?" Well look, Europa doesn't have an organisation in Manhattan somewhere to protect Europa. It's just not that organised, let's face it.
And it's true that Arthur C. Clarke wrote 2010, I think he has in there that the aliens say, "All these worlds are yours except Europa, attempt to no landings there." But that wasn't the aliens, that was Arthur C. Clarke, and it turns out that he was a hominid. Obviously, that shouldn't weigh into any of this.
So, of course it's worth it. It's the same with Mars -- yeah, there's some risk of contamination, and when you bring something back from Mars, there's even some small risk of that contamination. That's the nature of exploration.
And if you found biology on Europa, that's a big deal. In fact, in some ways, it's a bigger deal than finding life on Mars. Because if you find life on Mars, there's some chance that Mars contaminated the Earth four billion years ago. It could be that we're all Martians. The lower half of Manhattan is kinda Martian-like.
But you could do that and find that there's really only one kind of life. In the case of Europa, it's much harder for Europa to ever have contaminated Earth, due to matters of dynamics and stuff like that.
So if we find life on Europa, the consequences of that would be, "Guess what, Bob? Life is not a miracle. Life is an infection. Life is all over the place, life is as common as cheap motels." In a way, that would be terribly significant forever, for humanity to know that biology is just all over the place.
Is that worth a little risk of contaminating the ice on Europa? I would vote for it, you bet I would.
Gizmodo: The Europa Society in Manhattan is going to be pissed when they hear this.
Shostak: Yes, the Europa Society... I think they're located somewhere in Park Slope. I'm not sure.