LIFE IS A TREASURE WORTH FINDING

I’ve posted recently about the search for extraterrestrial intelligence and the (so far) lack of success. But why are we so focused on intelligence? Wouldn’t it be awesome enough just to discover life elsewhere in this vast universe? Jumping high-five awesome? For some reason most of the attention and all of the angst has been centered on the idea that there might be other species of beings out there that might be interested in us for the purposes of a) contacting, or b) conquering. Yet the search has come up empty. Well, maybe intelligent life is as rare as a politician with his hands in his own pockets, and there are lots of reasons it could remain hidden from us, but the discovery of any kind of life inhabiting other solar systems would be cause for celebration.

This week NASA announced a brand new coalition of scientific endeavours to be known as NExSS (Nexus for Exoplanet System Science). Each of the partner projects will focus on different aspects of the search for extraterrestrial life including refined spectrometers better able to detect Earth-like planets, how planets form and where, the potential habitability of exoplanets (from a human perspective), tidal dynamics, how organic elements reach planet surfaces, and a lot of other topics.

I love this idea, and not just because of its geek-cool acronym. The practical side is that the more we know about how habitable planets get that way and how life arises and survives elsewhere, the better we can understand the challenges of our own planet and maybe even find solutions to the damage we’ve done to its ecosphere. God knows, we need all the help we can get in that department. But beyond the practical is the pure stomach-tingling thrill of a treasure hunt. Finding carbon-based life on an exoplanet would be like finding a long-lost cousin you never knew you had (who doesn’t know about all the skeletons in family closets). No, bigger than that—it would be like living all your life in a sheltered village and suddenly finding out that there’s a whole world just beyond the trees. There was a hint of that when the first exoplanets were discovered in the mid 1990’s, but the confirmation of extraterrestrial life would ramp that excitement up to a whole new level. Think of all of the new questions, and the answers, and…more questions.

Does carbon-based life require DNA? A cellular structure? Does it always follow a birth-to-death life cycle, or could there be forms of life that are effectively immortal? What about sex—we’re always fascinated by sex.

What if we find life forms that aren’t based on carbon? There’s been speculation, but proof would really upset the bioscience applecart. And that could be a good thing. Sometimes the best way to advance is to throw everything you’ve known up in the air and see what new patterns form when it lands.

Whatever we learn about life elsewhere is bound to open our eyes to secrets our own planet has yet to offer up, because I’m certain we haven’t yet found every type of life the Earth has produced, hidden in the depths of the ocean or the planetary crust. Not to mention other bioscience implications like the discoveries of new potential medicines. Learning how extraterrestrial life copes with unique or harsh conditions might teach us how to protect ourselves from nasty surprises like cosmic ray bursts or asteroid strikes, too.

Most of all, I love this plan because the discovery of life elsewhere would give us somewhere to go and a reason to get there. The human race is at its best when we have goals that inspire us, nearly unattainable heights to climb. A treasure just beyond our reach that requires us to dig deep within ourselves and strive together in community.

We could really use something like that right now, and NExSS just might point the way.

ARE WE ALONE IN THE NEIGHBOURHOOD?

We look up at the stars and wonder if we humans are alone in this vast universe. It’s not a question we can answer yet (unless you’re a true believer in UFOs), but there sure are a lot of people working to estimate how much galactic real estate might support life.

Our Milky Way galaxy alone is thought to include 200 billion stars—maybe many more than that, and at least tens of billions of those are yellow-orange stars similar to our sun. But until the last 20 years or so, we really had no way to know if many of those stars had planets orbiting them. If we’re hoping to find life, the first step is to not only find planets, but planets in the habitable zone of their stars: the so-called Goldilocks zone: not too hot, not too cold. There are other considerations, like gravity and atmosphere, but even just finding rocky planets the right distance from their sun is a good start.

Since 2009 the Kepler spacecraft has been monitoring the brightness of more than 145,000 stars. Why? Because if a planet crosses in front of the star (between it and Earth) the light will dim just a tiny bit. Kepler can measure that. Another astonishing instrument called High Accuracy Radial velocity Planet Searcher (HARPS) in an observatory in Chile uses a high-precision spectrograph to also measure light, but in such a way as to detect motion. A planet orbiting a star will cause a tiny wobble in the star that HARPS can see. The Keck Observatory in Hawaii has been using a similar method to great effect for a couple of decades now. There are other efforts underway in the UK, Spain and elsewhere.

So with all this searching going on, how many planets have scientists really discovered around other stars? The number is approaching 700, and might even be higher than that by the time you read this. More than 1200 other possible candidates have been identified and are just waiting to be confirmed. Admittedly many of those are probably gas giants like Jupiter, but many are also smaller than Neptune and might be much closer to Earth in size and composition. But it’s the ones that appear to be in the habitable zone of their star that grab headlines. That number is still small, but growing. And even if only a small percentage of sun-like stars have a habitable planet, in a place as big as the Milky Way that still means potentially tens of millions of planets where life similar to Earth’s could exist.

It’s still not proof, but it sure does improve the odds. So if you’re getting tired of the Caribbean or Europe, have we got a long distance vacation destination for you!