Were I offered the chance to study again, I know what I would do. Astrobiology. In the last few years it’s been something I’ve followed. The trouble is, I’m easily interested in almost anything I come across. However, I would study astrobiology in a heartbeat. So, what is astrobiology?
Ever since humanity made its first baby steps beyond our thin layer of atmosohere astrobiology has looked to the stars, emerging as a discipline in its own right. It is the study of life on other worlds. Moreover, it is the study of life itself and asks the question: could life exist anywhere else?
We’ve all seen the movies and heard stories. The idea of life on other worlds has had a vice like grip on the human imagination for a very long time. Every single culture on Earth has some accounts of visitors from the sky and encounters with otherworldly beings.
From Judeo-Christian mythology and tradition to the various disparate and yet somewhat homogenous mythologies of Australia’s aboriginal people, it seems we’ve had visitors from the sky for quite some time.
At least so the stories go. Those stories will persist in one form or another for a long time to come, and the popular imagination is still fired up with tales of otherworldly visitors. Just trawl social media sometime and you’ll see what I mean. A search on YouTube: that paragon of level headedness, for a term such as “Area 51” will yield a miasma of conspiracy theories, alien “sightings” and general silly nonsense. Many of these videos have had millions of views. In my first search one particular video had over 20 million views. It was a “sighting” of an alien strolling across a road in some generic American desert setting.
People are eating this stuff up. But what does it have to do with astrobiology? Our desire for interstellar neighbours is always a little, shall we say, elitist? Does all extraterrestrial life need to be flying around in advanced spacecraft and spying on us: the cosmic equivalent of an ant farm?
(Are we that fascinating?)
Astrobiology specifically looks for life beyond earth. That life doesn’t need to be a wookie or a Borg drone. Something as simple as a bacterium would rock the worlds of astrobiologists everywhere.
Missions to other worlds in the solar system have had this in mind for decades now. Missions to Mars almost turned the science world on its head when micro traces believed to be produced by single celled organisms were relayed back to space agencies. Big news indeed. Life on another world. Not Yoda, to be sure, but better! The jury is still out on this “evidence” but time will tell!
You see, astrobiology is the search for life beyond earth. It is the application of a diverse set of scientific disciplines (which includes but isn’t restricted to) chemistry, geology, biology, planetolgy, ecology and astronomy to look for anything. Any life at all. If human or robotic explorers ventured across the gulf of space and found something as simple as a bacterium it would be a massive deal. From the time of earth’s formation circa 4.6 billion years ago life took around a
billion years to appear. The story of life isn’t the key point here. On earth life still took a long time to gain traction. It was only around 800 million years ago that anything as complex as a sponge first appeared, and it went through a pounding before all this happened. The Late Heavy Bombardment, a highly toxic and reducing atmosphere; likely similar to that on Titan today, which was replaced by another highly toxic atmosphere: oxygen. This change led to the greatest mass extinction this planet has ever known. An irradiated, toxic lethal planet somehow gave rise to life.
Astrobiology looks at life on this primeval earth and posits the question: if it could make it here, it kind of stands to reason that it could develop somewhere else. Earth now is a benign paradise, possessing a very particular set of attributes that enable life to thrive. Among these; a thick atmosphere and life giving heat from a nearby sun which respectively enable liquid water to exist at the surface and provide the fundamental energy for life to prosper. Earth possesses an active magnetosphere which shields life from cosmic radiation. These are only some of the factors that make earth just right, like the proverbial bowl of porridge. In fact, in honour of that famous metaphor, Earth is said to orbit the Sun in a “Goldilocks Zone” This means that we are just far enough from the sun that the temperature range is just right for liquid water to exist at its surface. Hence the thing with the porridge.
Many other worlds we’ve examined don’t have any or all of these qualities, but that’s no reason to dismiss them.
Life is seemingly turning up everywhere we look these days, and the more we look the more we see that life is extremely tenacious From the clouds above us to hadean environments deep within the earth’s crust to active nuclear reactors life seems to be able to survive anywhere.
That’s what gives astrobiologists hope.
This post is to be the outline of an upcoming episode on my “Ben’s Lab” YouTube channel. For any who are following the channel (thank you!) It will be undergoing renovations. The subject matter will focus more on things near and dear to my heart, and astrobiology is one of those things! If you like astrobiology please leave suggestions for episode ideas in the comments, or share this with others who like it as well.
References and resources:
This list is not comprehensive and is intended to begin those who are interested on beginning their own research;