Every day we find more exoplanets. With bigger and better telescopes on the horizon, we'll have far more observations of these planets than ever before — and NASA scientists are optimistic we'll discover alien life within decades.
On Monday, a panel of NASA scientists and engineers discussed the roadmap to the next generations of telescopes, and what they hope to learn. The Hubble, Kepler, and Spitzer space telescopes pushed our understanding of planetary dynamics. From the first tentative announcement of an exoplanet discovery, we're now listing literally hundreds of worlds beyond our solar system, scattered amongst the stars.
As we learn more, we're starting to narrow down how to identify planets that may support alien life. That life may not be spectacular — an equivalent to the rock-algae stromatolites that transformed the atmosphere of our own world might be easy to spot, but wouldn't be the most dynamic alien lifeform. We're getting good enough at interpreting even this limited data to make weather forecasts for exoplanets. Just imagine what we're going to do with the next generation of telescopes!
A new pair of telescopes are launching soon: the Transiting Exoplanet Survey Satellite (TESS) in 2017, and the James Webb Space Telescope in 2018. Kepler has found us hundreds of worlds; TESS is designed to track thousands of stars for that brief dimming that indicates the presence of a planet.
But where things get really exciting is with the James Webb Space Telescope. That telescope will be all about transit spectroscopy: picking the most likely worlds, and looking for signs of life. Light from the distant star will filter though its atmosphere, and if Webb is as good in practice as it is on paper, that tiny bit of altered light will be enough for us to analyze and characterize the atmosphere of alien worlds.
...this is where practical, logical scientists start talking about aliens. Earlier this year, NASA published a book on communicating with aliens. That wasn't just a stunt: from this panel, it's clear that NASA is treating finding aliens as a When, not an If.
Sara Seager, a planetary scientist at the Massachusetts Institute of Technology who was on the Monday panel, admits it's a long shot: "We have to get really lucky. With the James Webb we have our first chance, our first capability, of finding life on another planet. Now, nature just has to provide for us." Panelist Matt Mountain, a NASA telescope scientist, echoed the sentiment, asking "How lucky do we feel?"
NASA Administrator and astronaut Charles Bolden took a philosophical approach, concluding "It's highly improbable in the limitless vastness of the universe that we humans stand alone." But it was astronomer Kevin Hand who was boldest of all, musing, "I think in the next 20 years we will find out we are not alone in the universe."
That's right: a NASA representative actually directly listed a timeline for when we'll find alien life, even if it is "It's only not boring because it's from another world" single-celled immobile critters. But the crazy bit is, that might not be too wild of an estimate. If Hand is right or wrong with his timeline depends in part on where we go with the next generation of telescopes. That in turn depends on what sort of budget NASA gets, and what new technologies we develop.
James Webb Space Telescope concept art. Credit: NASA
The James Webb telescope will be enormous — 6.5 meter mirrors. To get it into space, the engineers are enacting the rocket scientist version of building a ship in a bottle. The mirrors are folded and tucked to squeeze into a rocket, a fraction of the size the behemoth will stretch in space. It's all really quite impressive, and I'm excited to start seeing its data on distant worlds.
But with telescopes, bigger is better, and scientists are always dreaming of something more. Bigger mirrors means more light collected, and better resolution. With a 20-meter telescope, we could spy on all small exoplanets, looking for life on planets like ours. The bigger our telescopes get, and the longer we look, the better our chances are for finding alien life somewhere out there. If we want to build that big, we're going to have to up our game for better launching systems capable of carrying the oversized load into orbit.
It's that moment of discovery that gets Mountain giddy, when one of his telescopes, or those of his colleagues, spots the markers of life on another world: "Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over—the possibility we're no longer alone in the universe."
So much of our science fiction deals with the moment of contact, the moment of discovery. Sometimes first contact in stories is hostile and sometimes it's celebratory, but whatever it form it takes in reality, it's going to be world-changing. And it's coming soon, even if it takes another few generations of telescopes or longer than twenty years to find alien life.
Watch the whole panel for yourself here:
Top image credit: NASA