The idea of aliens may seem absurd. But times change, as does science, says Phil Plait, and this makes the idea far more plausible than it once appeared.
One of the reasons I love astronomy is that it doesn’t flinch from the big questions. And one of the biggest is: are we alone?
Another reason I love astronomy: it has a good shot at answering this question.
Even a few decades ago hard-headed realists pooh-poohed the idea of aliens. But times change, and so does science. We’ve accumulated enough data that makes the question less far-fetched than it once was, and I’m starting to think that the question isn’t “Will we find life?” but rather “Which method will find it first?”
There are three methods that, to me, are the front-runners for finding life on other worlds. And I have an idea as to which one may find it first.
Life on Mars?
The first method follows the principle that when you’re looking for something, it’s best to start close to home.
We know of one planet that has life: Earth. So it makes sense to look for other places with Earth-like conditions: that is, liquid water, oxygen in the air, nutrients for growth, and so on.
The most obvious place to look is Mars. At first glance it appears dry, cold and dead. But if you can see past that, things start to look up. The polar caps, for example, have lots of frozen water, and we’ve directly seen ice at lower latitudes on the Red Planet as well – meteorite impacts have left behind shiny craters, digging up fresh ice from below the surface……
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