This Easter, I Want to
Believe
Mulder with
that poster and a picture of Saturn with a moon behind his head.
It’s Easter,
that time of year when millions of Christians celebrate Christ’s resurrection.
Now I’m not a religious person myself, but I greatly respect those who are. My
favourite composer – J.S. Bach – composed many of his (and perhaps Humanities’)
greatest works to the glory of God, after all.
When Carl
Sagan proposed placing a (vinyl-type) record aboard the interstellar-bound
space-probe to the outer planets, Voyager 1, he asked for musical suggestions
and an eminent biologist famously responded, ‘I would send the complete works
of J.S. Bach … but that would be boasting’. In the event, the ‘Voyager Golden Record’
did include several of JSB’s compositions, including the first movement of a Brandenburg
Concerto.
When you
think about it, the Golden Record suggests Sagan’s confidence that there must
be life out there – and intelligent life at that – to receive and appreciate
it. Looking back, it was a wonderfully optimistic, even naïve thing to do – an act
of faith. I’m not sure NASA would do the same today.
A few years
back I sat down to dinner with my oldest friend, Fred, who is a physicist and a
disputatious kind of chap. Fred and I almost always get into the kind of ‘lively
discussion’ our wives call arguments over dinner (check-out Wendy Cope’s oh-so-true
poem ‘Men and their Boring Arguments’). On this occasion, we ended up arguing
about aliens.
Fred and I
fall on opposite sides of the ‘is there life in the Universe’ debate. For Fred
is a believer in ‘Rare Earth’ (an idea expounded in a famous eponymous book) –
the idea that, for various reasons, there is something special about our planet
that makes it uniquely suitable for life. Meanwhile, I tend to the Copernican
view that there is nothing very special about Earth and that if we discount
some kind of creation myth then the Universe must be teeming with life.
It’s ironic
then that Fred chose this moment to hit me with a real below-the-belter:
‘Your belief
in aliens is basically religion,’ he said, with a sneer.
Ouch. You
see for a professional scientist like Fred, the surest, most insulting way to
rubbish a quasi-scientific opinion is to call it a belief.
In fact, of
course, both our opinions amount to ‘belief’ because there is no proof either
way … yet. Anyway, his accusation didn’t sting quite as he’d intended. I don’t
think belief is such a bad thing. I recalled Sagan’s Golden Record and Mulder’s
poster in the X-Files basement, his slogan for my one of my favourite TV shows.
Perhaps indeed I wanted to believe in universal life almost as much as Fred
wanted to be unique and special.
In the years
since our ‘mens’ boring argument’, however, the
evidence has started to mount and not, I have to say, in Fred’s favour. The
search for exoplanets has already yielded up a number of potentially habitable
worlds, whilst Earth-bound biology has steadily pushed back the boundaries of ‘habitable’
by finding life in all sorts of unexpectedly harsh places.
Then,
yesterday, came another piece of evidence to cheer Sagan and Mulder. At the
bottom of the news, below much more important stuff such as a huge U.S. bomb
and Kylie Jenner’s Prom, came NASA’s announcement that they had found the final
piece of circumstantial evidence for life in a very unlikely place – Saturn’s
moon Enceladus.
Saturn and
moons, as I saw them from the 60” at Mount Wilson – one of the largest
telescopes you can look through.
I got a good
look at Enceladus through the 60” at Mount Wilson last year. Through even the
largest telescope it’s just one of several star-like moons that cluster around
magnificent Saturn. Those Voyager missions didn’t discover anything much more. But
when the Cassini space probe (built at JPL, just a mile or two from Mount
Wilson) began investigating Enceladus a decade ago, it became clear the moon
was not the dead snowball we had imagined.
Enceladus
has water jets erupting from below its icy crust from active regions named ‘tiger
stripes’, perhaps from some kind of sub-ice ocean (or at least large bodies of
water of some kind). Cassini has sampled those jets over several close fly-bys
and discovered interesting compounds typical of deep-ocean environments where
life on Earth clusters around geothermal vents, separate from the rest of the
biosphere and with no need for sunlight to make food. Cassini has previously
found methane, carbon dioxide and ammonia. Now it has detected molecular hydrogen.
The discovery
of a simple and universal (most of the universe is made of hydrogen) gas
spewing out of Enceladus may not seem a big deal. Certainly, the BBC, who buried
the story, didn’t think so. But hang on. You see, the life found on Earth
around deep-sea hydrothermal vents depends on a food chain built on bacteria that
glory in the name ‘chemo-litho-autotrophic-hyperthermophiles’ (best sung - in
place of Mary Poppin’s ‘supercalifragilisticexpialidocious’)
that use chemical energy rather than sunlight to produce food. And those
bacteria, thought by many to be similar to Earth’s earliest life, can use
hydrogen as an energy source by combining it with carbon dioxide to produce
methane.
Let’s be
clear, NASA’s announcement isn’t the discovery of life at Enceladus. That would
have made the front page. Though the hydrogen could be a bio-marker, it could just
be the result of inorganic reactions between rocks and hot water. The point is that
if Enceladus did support life based on methane-producing bacteria around
deep-ocean vents like the ones on Earth, NASA have now detected all the markers
they would expect to: methanogenic
bacteria could exist in Enceladus’ sub-ice ocean.
This Easter,
amid all the depressing stories about Trump’s giant bomb and sabre-rattling in
the Pacific, it’s harder than ever to believe in the redemption of humanity. Bach’s
great Mass in B Minor ends with one of the most redemptive pieces of music I
know, set to the exhortation ‘Dona Nobis Pacem’, ‘give
us peace’; but it doesn’t seem like anyone up there is listening just now. Then
again, my own ‘religious’ (Fred’s words) desire to believe in something ‘up
there’ just got a bit stronger with what may prove to be a momentous piece of Easter
news from beyond the rings of Saturn.
A trinity of books about beliefs: the
King James Bible, a history of Area 51 and Rare Earth.