Every year scientists discover hundreds, if not thousands, of new species. Not just new species, actually. Occasionally, scientists will stumble upon a living fossil — a species thought to be long extinct.
In the fall of 2010, the very first census of the oceans came out. Marine biologists and other scientists around the world catalogued more than 250,000 species living in the oceans, but speculate there could be at least more than half a million that eluded their reach. Twelve-hundred new species were found, including a 21-foot squid and a living fossil Caribbean clam that ruled the sea for 100 million years but was documented as extinct in the 1800s.
Life we never thought could exist has been found in the most unlikely places — under intense heat and pressure, in anaerobic (oxygen-lacking) environments and even in toxic lakes. And yet, as much life as scientists have discovered over the course of our lives, there is still so much more waiting to be found.
We haven’t been to the bottom of all the oceans, into the depths of some of the densest jungles, or into the deepest cracks in the Earth. And there’s still so much of Earth’s early history that has yet to be written. Even with all the fossils we’ve found and “missing links” we’ve connected, those are just the teeniest percentage of a record depicting an Earth that once was.
And what about places that couldn’t possibly allow life as we know it to live?
What about other planets?
Interestingly enough, I came into this column with the intention of chastising NASA for spending too much time, money and energy on the search for extraterrestrial life. My idea was that because there was so much we don’t know about our own planet, shouldn’t we focus on that first, before blasting into space to find ET? As cool as it would be, I reasoned, it couldn’t be more important than solving every mystery of our own planet. But as I began my research, I found that I was more and more convinced that turning to outer space was like shining a mirror onto Earth — that looking at other planets could give some powerful insight into the search for the history of Earth’s evolution.
In 2009, NASA spent a copious amount of money to launch a probe called Kepler into space to find whatever stuff it could. So far, the spacecraft has found numerous extrasolar planets (planets orbiting a star other than our Sun), several of which could be good candidates for extraterrestrial life. Mostly though, Kepler has found massive planets that revolve so closely around their star that it only takes a few days to complete a complete revolution (Earth takes 365 days to complete a revolution), which means they are exceedingly hot.
What NASA is looking for are Earth-sized planets that are a habitable distance from their star. So far, a few of them meet these criteria — one is even 0.9 times the radius of Earth.
“Any of these would be the most Earth-like world ever detected outside the solar system,” Scientific American said.
The Kepler scientists eagerly claim that finding extra-terrestrial life outside our solar system is not too far off.
We have similar rocks in our own solar system — notably the moons Titan (Saturn), Europa (Jupiter) and Enceladus (also Saturn). These three moons are tantalizing to astronomers for a few reasons: They share characteristics of either early Earth, or they have possibly life-sustaining qualities (liquid oceans, Earth-like atmospheres, etc.). NASA is already making plans to explore Europa in 2020.
So my mind is changed — space exploration is just as important as Earth exploration.
Consider the evolution of planets in general. Everything started out as dust, and the bigger dust particles attracted the smaller dust particles to form chunks of rock, and the bigger rocks attracted smaller rocks to form massive chunks of rock. Eventually, planets were formed.
If all the planets were formed more or less this way, wouldn’t it be cool if we found a baby Earth? Maybe flying through outer space looking for aliens isn’t the waste I thought it was. If we can find a planet in the beginnings of life, we can watch it grow. We can witness the evolution of one planet and use that knowledge to study the evolution of our own planet. And in the process, we might just find ET.
[email protected]