By: SPACE.com Staff
Published: 04/04/2012 07:44 AM EDT on SPACE.com
The first true "alien Earth" will likely be discovered in the next two years, a NASA scientist says.
Astronomers have found more than 750 alien planets to date, and NASA's Kepler Space Telescope has flagged 2,300 additional "candidates" awaiting confirmation by follow-up studies. This haul has not yet included an Earth-like exoplanet — one that's the size of our planet and orbits at the right distance from its star to support liquid water and, possibly, life as we know it.
But that could change soon, according to Shawn Domagal-Goldman, a researcher at NASA Headquarters in Washington, D.C. who specializes in exoplanet biology.
"I believe Kepler will find a 'Goldilocks planet' within the next two years," Domagal-Goldman said in a statement. "We'll be able to point at a specific star in the night sky and say 'There it is — a planet that could support life!'" [Video: How to Find Earth's Alien Twin]
Studying a 'Goldilocks planet'
Some NASA officials appear to share Domagal-Goldman's optimism, for the agency is already looking into ways to study alien Earths once they're found.
It's difficult to investigate such worlds directly, since faraway Earth-size planets are small and faint, their dim light almost completely drowned out by the bright glare of their parent stars. But researchers are confident that an indirect approach, called transit spectroscopy, can reveal a lot about Goldilocks worlds.
This technique scrutinizes starlight that bounces off the atmosphere of an alien Earth on its way to our cosmic neighborhood. Such starlight carries a sort of fingerprint of the atmosphere, which astronomers can study to learn about the atmosphere's composition.
"The reflected light of an exoplanet tells its story," said Doug Hudgins, Kepler program scientist at NASA Headquarters.
One new mission under consideration, called Finesse, uses the transit spectroscopy method. Finesse, which is short for "Fast INfrared Exoplanet Spectroscopy Survey Explorer," would measure the spectra of stars and their planets in two situations — once when the planet is in view, and again when it's hidden behind its star.
The mission would be able to separate the planet's dim light from the star's blazing glare, revealing the composition of the planet's atmosphere in the process, researchers said.
NASA is also considering an observatory named Tess (Transiting Exoplanet Survey Satellite). Supported in part by Google, this mission is designed to find alien planets in our local galactic neighborhood. Tess would study hundreds of stars within 50 light-years of Earth, close enough to study in some detail.
"With better detectors and instruments designed to block the glare of the parent stars, these next-generation telescopes could not only find a Goldilocks planet, but also tell us what its atmosphere is made of, what sort of cloud cover graces its skies, and maybe even what the surface is like — whether oceans cover part of the globe, how much land there is, and so on," Hudgins said.
Domagal-Goldman expects big finds, and big surprises.
"We've found so many unexpected things about planets that now I expect to be amazed," he said. "When we can study a Goldilocks planet, I believe we'll discover something revolutionary about how life interacts with a planetary environment. Nature is so much more diverse than we anticipated."
Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.
Copyright 2012 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.