A press report a few days ago reported, “NASA has cleared the Europa Clipper mission to proceed through the final-design phase and then into spacecraft construction and testing, agency officials announced yesterday.” Too bad. The Europa Clipper mission will basically be a $4 billion dollar waste of money that won't produce any very important scientific results.
Europa is a moon of the planet Jupiter. The Europa Clipper mission will be solely focused on getting more information about this distant moon. But the Europa Clipper won't have the job of discovering what Europa looks like. We already know that, from previous space missions.
Europa (Credit: NASA)
The Europa Clipper spacecraft will take photos of Europa more close-up than previous photos. But there won't be any very interesting close-ups, due to the fact that the surface of Europa is almost featureless, consisting of frozen ice. So the Europa Clipper won't find any interesting geological features like the Valles Marineris on Mars. The most interesting features on the surface are merely cracks in the ice. Close-up photos of those won't provide photos that people will be pasting on their walls.
The reason why scientists are interested in Europa is that they think that there could be life in an ocean underneath the icy surface of Europa. Will the Europa Clipper be able to confirm that life exists on Europa? It seems not, for the mission does not include a lander.
But NASA scientists have a kind of “wing and a prayer” idea about how the Europa Clipper spacecraft might detect life. They hope that it might be able to fly through a water geyser erupting on Europa, and sniff signs of life in water vapor. At 2:11 in the NASA video here, we are told that Europa “might be erupting plumes of water,” and that “if that's true, then we could fly through those plumes with the spacecraft.” There are two reasons why there is virtually no hope that such a thing would ever succeed in detecting life.
The first reason is the enormous improbability of abiogenesis, life appearing from non-life in an under-the-ice ocean of Europa. To calculate this chance, we must consider all of the insanely improbable things that seemed to be required for life to originate from non-life. It seems that to have even the most primitive life originate, you need to have an “information explosion,” a vast organization windfall comparable to falling trees luckily forming into a big log-cabin hotel. Even the most primitive microorganism known to us seems to need a minimum of more than 200,000 base pairs in its DNA (as discussed here).
Scientists have been knocking their heads on the origin-of-life problem for decades, and have made very little progress. The origin of even the simplest life seems to require fantastically improbable events. Protein molecules have to be just-right to be functional. It has been calculated that something like 1070 random trials would be needed for a single type of functional protein molecule to appear, and many different types of protein molecules are needed for life to get started. And so much more is also needed: cells, self-replicating molecules, a genetic code that is an elaborate system of symbolic representations, and also some fantastically improbable luck in regard to homochirality (like the luck of you tossing a bucket full of pennies on the floor, and having them all turn up heads). The complete failure of all attempts to search for radio signals from extraterrestrials would seem to provide further evidence against claims that the origin of life is relatively easy.
There is another reason the “sniff life from a water geyser's vapor” would have virtually no chance of succeeding. The evidence that water plumes even occur on Europa is only borderline, with some research casting doubt on the evidence. If water plumes occur on Europa, they seem to occur only very rarely and for a short time. The paper here suggests plume “ballistic timescales of only 1000” seconds, making the chance of a spacecraft flying through a plume incredibly unlikely (less than the chance of me dying from stray gunfire).
It would not at all be a situation like the following:
Mr. Spock: Captain, I detect a water plume from a geyser on Europa.
Captain Kirk: Quick, hurry over there while it lasts! Go to Warp Factor 8!
If a rare water geyser eruption occurred, the Europa Clipper spacecraft probably would not be anywhere close to Europa's surface. This is because the Europa Clipper mission plan does not have the spacecraft orbiting Europa. Instead, the plan is to just have the spacecraft repeatedly fly by Europa, flying by it about 45 times, so that the spacecraft does not pick up too much deadly radiation near Europa. With only such intermittent appearances close to Europa, the spacecraft would need an incredibly lucky coincidence to occur for the spacecraft to fly through some short-lived water plume ejected by a geyser.
We can compare this scheme to the “wing and a prayer” scheme of a traveler who plans to travel without any food to a city, the plan being that the traveler will walk with his mouth open and hope that someone discards food by throwing it into the air, with the food luckily landing in the traveler's mouth.
At the 2:52 mark in the NASA video, we get some talk that reveals the main motivation behind Europa exploration. It's all about trying to prove (contrary to all the known facts) that “the origin of life must be pretty easy,” to use the words in the video. For people with certain ideological tendencies, proving that the origin of life was easy is like a crusade. But zealous crusaders often don't make logical plans, as we saw during the Middle Ages when there were foolish missions such as the Children's Crusade, in which an army of children marched off to try to capture the Holy Lands from Muslim armies. The Europa Clipper mission's odds of biological detection success seem like the odds of success faced by the Children's Crusade.