Is there life out there in the universe? Probably

[Garrison L. Hilliard]

Let's take a moment to expand your reality.

The late astronomer and astrobiologist Carl Sagan hypothesised that
there are more stars in the universe than there are grains of sands on
the entire planet earth.

Given that this estimation is physically impossible to verify, the
scale presents an intriguing peek into the near absolute vastness of
our universe: each of those stars could have planets - and any of
those billions upon billions of worlds might be home to life.

On Wednesday NASA announced that it had discovered an entire solar
system, with 7 exoplanets (dubbed the 7 sisters). Three of those
planets could potentially sustain life. The star TRAPPIST-1 is located
39 light years away. Cosmically this makes the system one of our
neighbours, even though it's about 351 trillion kilometres away.

Our universe is not infinite. It has a beginning and it will have an
end. But because our universe is so incomprehensively vast,
statistically, there is a high chance that there is life out there in
the blackness.

Our sun is just one star out of an estimated 100 to 400 billion stars
in the Milky Way galaxy, and this galaxy is one out of approximately 2
trillion galaxies in the observable universe.

Surely there has to be life out there?


(Hubble Deep Field image of galaxies in a small patch of sky - Credit:
NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of
California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09
Team)

This porridge is just right

Astronomers talk about planets being in the habitable zone. An easier
moniker to understand is the "Goldilocks Zone" – and it is this space
that allows a concept like a "Mama Bear" to be able to exist at all.

Earth is in the Goldilocks Zone. This means that it is not too far
away from the sun that we would all freeze to death, or too close for
us to all turn into human fireballs. Importantly, it allows water to
exist as a liquid.

Three of the planets orbiting TRAPPIST-1 are in the Goldilocks Zone.



The eerie silence

If the universe is so vast, why have we not made contact with any
civilisations yet?

We point radio telescopes at the sky and listen for signals and we
peer through telescopes looking for a spark in the void, and so far we
have been able to detect diddly-squat.

The easiest answer is that the distances between us and any alien
civilisation is so large that any signals we send their way, and vice
versa, will reach Earth after humans are extinct and the planet is a
molten rock.

Another possibility is that the aliens are either not advanced enough,
or advanced so completely beyond us, that they are beyond our
comprehension. So either the aliens are just single cell organisms, or
5th dimensional beings.

Try explaining the concept of breathing to an ant, let alone the
theorem of Pythagoras. Either we are the ants, in comparison to the
aliens, or they are the ants to us. The barriers to communication and
understanding, like the scale of the universe, are possibly too vast.

While it is the subject of science fiction, it is possible that aliens
are hostile. The colonialists looked at the world as a place to reap
resources, populated by what they deemed as "savage people". Maybe an
extraterrestrial intelligence sees Earth as a place of resources,
populated by savages?

Conversely, maybe they think we are too petty, fighting among
ourselves, electing leaders that use their money to build a lavish
home in place called Nkandla.

So maybe they are waiting for us to evolve past this?

A pale blue dot

While it is fanciful to speculate whether life exists on other worlds,
I'd argue that the reason we like to think about it is because we are
uncomfortable with the way things are on our current home, a
blue-green rock hurtling through space.

This sense of perspective is enough to make us question whether all
the things we agonise over and the weird nationalistic things we give
our lives for, really matter in the grand scope of the universe.

Coming back to Carl Sagan - In 1990, he requested that Nasa turn the
camera around on the Voyager 1 space probe as it left the solar system
and take a picture of the earth. The image of this blue dot, elicited
from Sagan a sobering but awe inspiring look at our place in this
universe:



"Look again at that dot. That's here. That's home. That's us. On it
everyone you love, everyone you know, everyone you ever heard of,
every human being who ever was, lived out their lives. The aggregate
of our joy and suffering, thousands of confident religions,
ideologies, and economic doctrines, every hunter and forager, every
hero and coward, every creator and destroyer of civilization, every
king and peasant, every young couple in love, every mother and father,
hopeful child, inventor and explorer, every teacher of morals, every
corrupt politician, every "superstar," every "supreme leader," every
saint and sinner in the history of our species lived there-on a mote
of dust suspended in a sunbeam.

"The Earth is a very small stage in a vast cosmic arena. Think of the
endless cruelties visited by the inhabitants of one corner of this
pixel on the scarcely distinguishable inhabitants of some other
corner, how frequent their misunderstandings, how eager they are to
kill one another, how fervent their hatreds. Think of the rivers of
blood spilled by all those generals and emperors so that, in glory and
triumph, they could become the momentary masters of a fraction of a
dot.

"Our posturings, our imagined self-importance, the delusion that we
have some privileged position in the Universe, are challenged by this
point of pale light. Our planet is a lonely speck in the great
enveloping cosmic dark. In our obscurity, in all this vastness, there
is no hint that help will come from elsewhere to save us from
ourselves.

"The Earth is the only world known so far to harbour life. There is
nowhere else, at least in the near future, to which our species could
migrate. Visit, yes. Settle, not yet. Like it or not, for the moment
the Earth is where we make our stand.

"It has been said that astronomy is a humbling and character-building
experience. There is perhaps no better demonstration of the folly of
human conceits than this distant image of our tiny world. To me, it
underscores our responsibility to deal more kindly with one another,
and to preserve and cherish the pale blue dot, the only home we've
ever known."

- Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space


* Ahmed Areff is national news editor of News24.

Disclaimer: News24 encourages freedom of speech and the expression of
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