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 acidsnecessary 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.
