It’s a big universe out there.
One big, lonely, quiet universe…But not empty. With all the billions upon billions of stars, galaxies, nebulas and planets, it’s the most crowded place in existence.
And yet, we still have yet to find anything that’s quite like, well, us.
Which is strange, because for all of our originality, the materials that exist on Earth are found all over the place. Our star is kind of a run-of-the-mill yellow dwarf. Our planet is on the average side of small. The rocks under our feet can be found scattered through the stars.
So why is this average pile of rocks with adequate proximity to sunlight the only spinning ball in space with life on it?
Or is it?
Dr. Jon Jenkins is a NASA senior research scientist at the Search for Extraterrestrial Intelligence Institute (SETI), and is the analysis lead for the Kepler Mission. Kepler uses a space observatory launched in March of 2009 by NASA to discover Earth-like planets orbiting other stars. Jon heads up the group of about two dozen scientists and programmers who designed and built the software that makes this dramatic search for other worlds possible.
With a brightness precision of 20 parts per million, the Kepler spacecraft should be able to discover planets that are the same size as the rocky, inner orbs of our own solar system. By making an inventory of such worlds, Kepler will answer one of the most intriguing questions in astrobiology: are Earth-sized planets abundant or rare?
The answer may surprise you.
“So far, we’ve detected over 3600 planetary candidates,” he says. “About 150 or so have been directly confirmed or validated. Statistically we expect 80 to 90 percent of these 3600 planetary candidates to be real bonafide planets.”
You hear that, Earthlings? We may not be an island unto ourselves after all.
Jon tells me that most of these are Neptune size or smaller, which is pretty impressive. Neptune is only four times larger than the Earth by radius, compared to Jupiter which is ten times larger.
So far the results of the Kepler mission show that the planets twice the Earth’s size and smaller actually are much more plentiful than larger planets around stars in the solar neighborhood.
“It’s been a cornucopia,” he says with enthusiasm. “We’ve found things that we didn’t expect to find.”
For example, Kepler detected the first multiple transiting planet systems that were discovered. These are cases where you see not just one but sometimes six, seven or eight planets all transiting, or crossing the face of the star.
This phenomenon indicates that nature likes to form planetary systems in a plane and that’s consistent with the prevailing theories of how the solar system formed.
“It’s really been a title wave of results from Kepler, given that we’ve more tripled the number of planets that we know about and greatly extended the kinds of planets that we know about, including circumbinary planets,” Jon says.
A circumbinary planet is a planet that passes by two stars. The Kepler team nicknamed the first discovery of this unique planet type Tatooine, after the Star Wars planet which also orbited two suns. Hopefully it’s a more friendly planet than Tatooine.
But what is really astounding is the fact that within the first six or seven examples of circumbinary planets – a completely different kind of planetary system than we live in – Jon and his team found the first planet in the habitable zone.
Which means they found a planet in the right place and the right size that could hold life as we know it.
“That doesn’t mean it’s inhabited, but it took a long time and a lot more discoveries of planets around single star systems before we found the first super-Earth in a habitable zone of a single star system.”
So what is a habitable zone and how do the experts determine which planets make the cut? This video explains all there is to know about that (and some of the new planets that have been uncovered as well):
Video Provided by NASA Solar System YouTube Channel
By the numbers (so far), approximately fifty or so planets in the habitable zone that have been discovered by Kepler. About ten of those are less than twice Earth’s size.
“There’s a certain amount of uncertainty in that because we’re still learning about the properties of stars that we’re observing,” Jon explains. “Because we only measure the relative size of the planets and the size of the star, we need to characterize, to follow up observations to characterize the star better so that we have a more firm grasp on how big the planet really is, and also on hot the planet is.”
Now they still have a long way to go before we can zero in and observe any of these planets in depth, but this is a significant finding. It’s the start of the discovery of things we’ve only speculated about for centuries. Dr. Jenkins puts it best.
“What I find so appealing about Kepler is that it’s zero order discovery science,” he says. “We’re discovering something about nature that we’ve wondered about for thousands of years. The ancient Greeks wondered whether there were planets around other stars. It’s something that I myself as a child, would lay outside in the summer grass and look at the sky wondering if there were beings on planets around those small dots of light, looking up into their night sky in our direction and asking the same question.”
This is groundbreaking research because it gets us that much closer to answering that fundamental human question: Are we alone in the universe?
I think that question is closer to being answered than you might think.
“If I had to guess, I would have to say I doubt that we’re alone,” Jon tells me. “When we look out into the interstellar medium, we find the building blocks for planets everywhere. We find the building blocks for life. It’s hard to imagine that the conditions that permitted Earth to form and for life to arise on Earth are unique to our planetary system, to our solar system.”
Even with the technological set back regarding the mechanical failure in May of 2013, and having only studied three years of the data so far, Jon says they have a lot of unprecedented new information that will help us to understand the universe a little bit more. Unexpected variables notwithstanding.
“There are a lot of things that you can’t predict,” he says. “I think it’s the same in science and it’s similar certainly in military applications. Whether you’re in the field or whether you’re in space, you can’t predict all of the things that are going to happen in that environment and you simply have to be facile and flexible and robust and willing to go back to the drawing board when things don’t work out the way you expected them to, and you learn things.”
Which is exactly what Jon and his team of scientists are doing; learning things.
Their work continues to uncover more and more about the small slice of space we’re researching every day. Kepler is so exciting because it helps us discover something today that we could only wonder about for thousands of years.
Imagine what wonders we will know tomorrow.
Thanks to NASA and the SETI institute for their contributions to this article and to our single-planet species, for which we will be eternally grateful.
Want to know why #SpaceMatters? Check out some of our other space-based stories!
Jessica L. Tozer is a blogger for DoDLive and Armed with Science. She is an Army veteran and an avid science fiction fan, both of which contribute to her enthusiasm for technology in the military.
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