Galaxy-IC-3418. Source: NASA
This was my first astrobiology article, originally published on Yahoo; it gives a very basic overview of the subject of astrobiology, the possibility of extraterrestrial contact, and the idea that human life may not be entirely of this planet.
Can intelligent life arise in the
cosmos? The existence of human beings is living proof that it can. So
that’s the title of this article covered. But does life exist
elsewhere in space? The scientific community has come round to
the idea that it almost certainly does. Astronomers from SETI (Search
for Extraterrestrial Intelligence) recently told the United States
Congress that we would be able to prove within the next 20 years that
alien life exists.
The scientific pursuit for knowledge of
life in the universe is called astrobiology. Still think alien life
equals flying saucers and little green men? Well, astrobiology is a
very real, and very active, branch of scientific enquiry. Institutes
of research such as NASA Ames and SETI
have focused on some key aspects of astrobiology, including the
search for extrasolar planets, the study of extremophiles (organisms
that thrive in extreme conditions), and the conditions required for
life to appear in the first place.
You may think that Earth is unique in
having life, but there may be other places even within our own solar
system where life may exist, such as Enceladus, one of Saturn’s
moons, with is thought to have an ocean of water under its frozen
surface. There is clear evidence that Mars once had water flowing on its surface, so even our closest neighbor may have harbored at least
primitive life in its past – and perhaps it still does.
Beyond our solar system, other planets similar to Earth may also have
been the birthplace of living organisms. Planets such as the newly
discovered Kapteyn b are likely to have at least some of the
conditions necessary for life. Interestingly, Kapteyn b is also
relatively close to us – only 13 light years away – meaning that
we may have a chance of visiting it... once we make the breakthroughs
in physics required to master interstellar travel, that is.
Given the age of the universe and the
likelihood that there are countless places suitable for life to
arise, it is possible that some of these have developed intelligence.
Of these, some may have organized themselves into civilizations,
developed technology, and even mastered space flight. Other worlds,
much older than our own, would have had more time to develop, and may
possess knowledge and technology far in advance of our own.
What would happen if we actually made contact
with an extraterrestrial civilization? Given the likelihood of their
existence, and the possibility that some of them may be capable of
advanced space travel, a visit from another race is plausible, if
unlikely. What implications for civilization would a meeting
of our cultures hold? Even knowing that they exist, via direct
obervation, or through radio or other communications, would have a
profound effect on our society. Religious beliefs, political
ideology, scientific knowledge, even the way in which people go about
their daily lives – everything would be affected in ways that are
difficult to predict. In short, it would be the single most important
shift in human perspective ever.
That’s assuming ETs don’t just
destroy us outright: a visiting envoy may unwittingly carry diseases
to which we would have no immunity; or worse: they may actively seek
to eradicate us. A highly advanced race may view us as dangerous,
backwards and barbaric, and they’d have a point. Or they may be
after our resources, what’s left of them. At the very least, the
Earth would certainly be of scientific interest to a visiting race.
Physicist Stephen Hawkins has warned against making our position
known, since extraterrestrial races may not have our best interests
at heart.
But what are our best interests,
anyway? After all, it could be advantageous for Earth to be part of a
consortium of civilizations, provided they let us in. To be able to
share scientific knowledge, to learn and make use of new discoveries,
and to understand incredible new cultures, would broaden humanity’s
horizons in ways our ancestors could never have imagined.
Never before have we been so close to
finding extraterrestrial life. But what if the distinction between terrestrial and extraterrestrial life isn't quite that straightforward? The theory of
panspermia describes the ability of microorganisms to propagate
suitable habitats in space, surviving the harsh vacuum between
worlds, by travelling on meteorites and other space debris. Is it
possible that some of the bacteria and viruses on Earth were actually
brought here by meteorites? Considering that part of human DNA actually comes from viruses
it may be possible that human beings are at least partially
extraterrestrial in origin. But even without extraterrestrial virus
DNA, the idea that we are not entirely of this Earth is a practical
certainty: NASA scientists have found some of the amino acids
necessary for life on comets, confirming that some of the components
of life came to Earth from space. The line between terrestrial and extraterrestrial is being
continually blurred; Earth biology is truly a blend of astronomical
sources.
We are close to discovering that life
exists elsewhere. As soon as scientists find even the first bacterium
in space, we will have to accept that we may not be alone, and that
one day we may take our place in a far wider community than we had
previously imagined.
