There is a revolution going on in the world of astronomy. It was less than ten years ago, in 1995, that the very first extrasolar planet, named Bellerophon, was discovered to orbit the "nearby" star 51-Pegasi. It's only 50.9 light years, that is, 299,000,000,000,000 miles, or 299 million million miles, away. Just a hop, skip, and a jump, for the Starship Enterprise traveling a warp-speed. The Bellerophon was discovered from a ground-based telescope. The Kepler Space Telescope was launched in March 2009, which could try to identify planets with out interference from light pollution or an atmosphere. This has led to an explosion in exoplanet data. The basic method (there are others) for detecting exoplanets involves calculating "light curves." A sensitive light detector is focused on a star and the amount of light detected is measured over time, generating a graph similar to that shown in the picture above. Planets that are too small or too large cannot be detected. Also planets that do not revolve edgewise to us are undetectable. Now there are, according to the most recent NASA ExoPlanet Archive, 2712 candidate planets including 837 planets around 653 stars. Special attention has been directed on the search for "Goldilocks" (i.e. Earth-sized) planets, that fall into the "Habitable Zone," defined as a planet that is in a pressure and temperature range that might support liquid water. Extrapolating from these numbers, there is an estimated 17 BILLION Earth-sized planets--and that's only in the Milky Way Galaxy. Catch your breath for a moment, and contemplate this number.
So, it is clear that there is plenty of potential life-harboring planets, but how likely is it that life is actually there? I direct to your attention the water bears, or tardigrades. Tardigrades can survive a remarkable variety of conditions on Earth, including extremes of starvation, temperature, dessication, and radiation. Previously, only lichen and bacteria were known to be able to survive exposure to the vacuum and radiation of space, but apparently water bears can survive for at least ten days and still produce viable offspring.
So, in the opinion of this humble blogger (All right, I'm not so humble.) given the incredible adaptability of life, coupled with apparently numerous Earth-like exoplanets, it is not only possible, but downright LIKELY that there is life on other planets. I just hope, and I'm considerably less sanguine about this probability, that some day our descendents, or whatever species inherits this planet from us, figures out a way to get to these planets and take a look.
Feast your eyes on the magnificent picture of a tardigrade that was recently featured by NASA Astronomy Picture of the Day and is available for sale from here.
So, it is clear that there is plenty of potential life-harboring planets, but how likely is it that life is actually there? I direct to your attention the water bears, or tardigrades. Tardigrades can survive a remarkable variety of conditions on Earth, including extremes of starvation, temperature, dessication, and radiation. Previously, only lichen and bacteria were known to be able to survive exposure to the vacuum and radiation of space, but apparently water bears can survive for at least ten days and still produce viable offspring.
So, in the opinion of this humble blogger (All right, I'm not so humble.) given the incredible adaptability of life, coupled with apparently numerous Earth-like exoplanets, it is not only possible, but downright LIKELY that there is life on other planets. I just hope, and I'm considerably less sanguine about this probability, that some day our descendents, or whatever species inherits this planet from us, figures out a way to get to these planets and take a look.
Feast your eyes on the magnificent picture of a tardigrade that was recently featured by NASA Astronomy Picture of the Day and is available for sale from here.
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