When I was little, my family used to go to a restaurant called Space Aliens. It was a bit like Chuck E. Cheese but instead of a mouse, it was alien themed — the little green kind. The dining area was decked out with all the typical sci-fi space gadgets (UFOs, spaceship control panels, galaxy murals, etc.), the play area had space-themed games, and the prizes were gizmos of the alien variety — stickers, statues, and other miscellaneous trinkets. As a young kid, it was fun to see what size alien statue I could win by playing the arcade games, but as I got older, I started to ponder whether aliens were actually real or not.
In 2020, right before the world shut down, my friends and I took a spring break trip to New Mexico, USA — the destination of note: Area 51. Turns out tourists can’t actually access Area 51, but we did enjoy the town closest to it, particularly the small business offering sets of alien statues to take pictures with. Again, those alien statues were the stereotypical alien depictions that I’m sure comes to mind for most people.
Modern movies have branched out at least. Star Wars, Star Trek, and Guardians of the Galaxy are a few of the relatively recent movies that come to mind. Most of the aliens in these movies look nothing alike; in fact, they look different depending on which planet they originate from. This concept of different planets hosting different types of life forms could actually be the more realistic scenario.
Exobiologists, or astrobiologists as they are more commonly referred to now, are scientists who use modern science to search for life elsewhere in the universe. The problem they run into, though, is that nobody really understands what life is yet. Sure, we know life exists on Earth. To us, living systems are the plants, animals, bacteria, and people we encounter on a daily basis. Biological organisms are life, but why? We see the macro version of life. Take humans, for example. We eat, we breathe, we sleep, blood pumps through our veins, we grow, we die. We are alive. Now think about grass. Grass grows, it takes in nutrients, it participates in photosynthesis (analogous to respiration in animals), and it dies. Neither example looks like the other, yet we know that both are alive. How then, can we determine what life is, if all examples look different?
One option is to zoom in to look at the processes happening inside the organisms. At the micro-scale (10-6), we start to see cells which have also been deemed to be alive. These cells take in nutrients, participate in (cellular) respiration, carry out functions, then die. Zoom in even further and we find information about the organism encoded in DNA that is constantly being replicated, transcribed, and edited. That DNA is made up of amino acids which are structures made up of many atoms chemically bound together. At what point do we stop saying something is alive? Then, even if we can determine what life is, how can we find it on other planets?
Stay tuned for next week’s article where we will explore the question “what is life?” through recent publications in peer-reviewed journals.
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LambCHNOPS 