16×9: The search for life on other planets
FULL STORY: Search for Life
It seems every year scientists announce how close we are to discovering life on another planet. All the signs are there but, so far, finding life beyond earth has eluded us. Still, the search isn’t letting up anytime soon.
There has been some good progress over the last decade or so. We have found water on the moons of Saturn and Jupiter, discovered that fresh water existed on Mars three billion years ago and, just last week, Kepler Mission scientists confirmed 715 new planets in other systems in our galaxy. They argue that some of these “exoplanets” (planets outside our solar system) could be “Earth-like”.
GALLERY: Artist rendering of exoplanets. Exoplanets are planets outside our solar system. They remain inside our galaxy, but are circling other stars. Scientists confirmed 715 new planets last week, bringing the grand total of confirmed planets to 1,700. With each discovery, it becomes more probable that Earth-like worlds might exist.
Exoplanets excite me the most. As a kid, I loved to recite the names of the planets (remember the mnemonic device My Very Educated Mother Just Sent Us Nine Pizzas?) So, when the first planet outside our solar system was discovered in the early 1990s- it blew my mind. There are MORE planets? There could be OTHER Earths?
Which is why the search for life is so compelling to me. Everything changes. Each time a new planet is discovered, our universe feels bigger, we become smaller and the possibility of life outside Earth becomes stronger.
WATCH: Carolyn Porco, planetary scientist and imaging lead for the Cassini Mission, talks about the discovery of geysers on one of Saturn’s moons, Enceladus, which could be a possible indication of life.
But the problem with the search for life is we don’t necessarily know what we are looking for. It is limited to searching for what we recognize as life here on Earth. So, while we have learned a lot and tested even more, the universe keeps coming up with surprises for us. Instead of providing answers, there always seem to be more questions.
As far as we know, there are three basic ingredients for creating life: liquid water, energy (like heat) and organics (like carbon). There is a delicate balance to sustaining life: having the right chemical, biological composition and environmental conditions and so far we know only Earth has managed it.
WATCH BELOW: Adam Steltzner led the landing team for NASA’s Curiosity rover- the biggest rover ever sent to Mars. He describes the challenges to landing a one tonne robot on a distant planet.
There are a few big contenders for life outside our planet. About four billion years ago, Mars had an atmosphere; there was flowing water in habitable lake systems, organic materials in the soil. The potential for life has been acknowledged by NASA scientists. But somewhere along the line, Mars – a planet quite similar to Earth- went off the rails. Its atmosphere shrank, allowing in too much radiation, the water dried up and any life that might have lived is no longer. Could the same thing happen to Earth?
Then there are the moons of Saturn – Titan and Enceladus. And this is where things get fun.
Titan is a weird, spooky place and my favorite because it seems so strange. There are lakes of liquid hydrocarbons like methane on its surface, making it the only place, other than Earth, to currently have liquid on its surface (but liquid methane might not smell the nicest). It’s cold and hazy and it seems like a place a Tim Burton film would be set. But without water, there is no life.
GALLERY: Images of Titan, Saturn’s largest moon, whose surface has dozens of lakes filled with liquid hydrocarbons like methane. It is the only place, other than Earth, that has liquid on its surface. Images taken from the Cassini spacecraft.
One argument is that “non-water-based life” could exist there, a yet-to-be-proven life form that uses organics, or something other than water, to survive. Non-water based life freaks me out. It’s too much like the T1000 (the Terminator).
Enceladus, a moon of Saturn about the size of Arizona, is probably one of the biggest contenders, which is a little surprising given its small size (it should be too cold). But, along its south pole, 100 geysers spout ice and water vapor chocked full of organics. Imagine a forest of Old Faithfull’s from Yellowstone Park, but on an icy, dark moon in Deep Space.
More evidence collected last year convinced scientists that this ice and vapor was coming from a hidden sea of salty, liquid water 40 kms under ice, mixing with heat and organic matter – life could be brewing underneath Enceladus.
GALLERY: Images of Enceladus, a moon of Saturn, and her 100 geysers spewing ice water and vapor into space. It is believed that the ice is coming from a sea of salty liquid water deep beneath the moon’s surface. Images take by the Cassini spacecraft.
Enceladus has been called one of the most habitable places for life outside Earth (At the very least, simple microbial life. At the very best, mermaids) and all we have to do it hang out on top of a geyser and stick out our tongues and we will know if there is life. I would volunteer for that.
But it seems to me that as we discover new planets, develop new technology to scour distant planets (one day we might have manned missions to Mars, or rovers on Enceladus), we realize just how much we have invested in finding life elsewhere. So much time and effort for something that might not exist. But I don’t think anyone is willing to give up just yet.
WATCH: All 16×9 investigations the week of March 8, 2014
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