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.
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