May 1, 2014
Sneaky Space Aliens
If alien life really does exist out there, somewhere in the universe, I really hope it is something like the Vulcans from Star Trek. Note that this is not due to any preference of Star Trek over other science fiction series, but rather an observation of all the not-so-friendly alien life we see in movies, television, and other media. Seriously, would you rather have a space elf giving you the secrets to advanced medicine, space travel, art, and culture, or a xenomorph from the Alien(s) movies? Or the invaders from The Avengers? Or any number of Dr. Who villains? Daleks? No thank you.
No matter what type of life might actually be out there, the quest to find it is a tricky one. More so now considering recent evidence that our current methods of detecting alien life on far-off planets might not be as reliable as we had hoped.
In a new study from the University of Toronto Scarborough, a team of international researchers led by UTSC Assistant Professor Hanno Rein of the Department of Physical and Environmental Sciences noted that the methods used to detect life – more accurately, “biosignatures” – on exoplanets is likely going to lend to results that are false positives. Environments that contain multiple chemicals like methane and oxygen in an exoplanet’s atmosphere is one of the things our current detection protocols deem an example of a biosignature, which means evidence of past or present life. What Professor Rein and the team discovered is that a lifeless planet with a lifeless moon is able to simulate these same results, meaning that any results found using these methods need to be reconsidered. A lot of research also uses modeling in order to try and estimate what the atmosphere of these exoplanets might be like, but with our present technology these are unable to make any sort of conclusive observation. Our current methods are able to estimate the size and temperature of these far-off worlds, which determines whether liquid water could exist on its surface. This is commonly considered to be a very important criterion for whether an exoplanet is able to host life, but it alone is not enough to confirm any sort of biosignature.
At present, the resolution we would need in order to properly identify if an exoplanet had a biosignature is impossible to produce. According to Professor Rein, “A telescope would need to be unrealistically large, something one hundred meters in size, and it would have to be built in space. This telescope does not exist, and there are no plans to build one any time soon.” Unfortunately.
At present, there are 1,774 known exoplanets out there. It sounds like a lot, but this pales next to the more than one billion planets that could exist in the Milky Way Galaxy alone. Still, there is still reason to hope that we might discover some form of life out there. According to Professor Rein, we just need to be doing it in the right way. “We should make sure we are looking at the right objects,” he says, mentioning a recent discovery of a liquid ocean on Enceladus, one of Saturn’s moons. “As for exoplanets, we want to broaden the search and study planets around stars that are cooler and fainter than our own Sun. One example is the recently discovered planet Kepler-186f, which is orbiting an M-dwarf star.”
The search for alien life on distant worlds goes on, and knowing what does not work will surely help us discover methods that do. Even so, again, I am still hoping for the Vulcans.
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