Will *You* Spot the First Truly Earthlike Planet?

UPDATE: In Wednesday’s press conference, the Kepler team announced the new public data includes readings on several hundred new planetary candidates. The findings increase the number of planet candidates Kepler’s found to 1,235.

Of these, 68 are roughly Earth-size, 288 are super Earth-size, 662 are Neptune-size, 165 are Jupiter-size, and 19 are larger than Jupiter.

Of the 54 candidates found in the habitable zone, five are close to Earth-size, while the other 49 range from up to twice the size of Earth to larger than Jupiter.

In March 2009 NASA launched the Kepler spacecraft, an orbiting telescope that was designed to search for small, rocky planets like Earth that orbit in the habitable zones of sunlike stars.

Like most space-based missions, Kepler carries a price tag that might sound astronomical to the average taxpayer: About $600 million gets you design, construction, launch, and operation of the spacecraft as well as professional scientific analysis of the data.

Really, that’s a bargain compared with some space missions. For example, the beloved Hubble Space Telescope has so far cost the American public anywhere between $4.5 and $6 billion.

Plus, just two years after launch, Kepler has so far confirmed nine new planets in its field of view, and a NASA presser tomorrow promises even more planetary goodies.


Kepler’s field of view, the >100,000 stars between the constellations Cygnus and Lyra.

—Picture courtesy Carter Roberts

But still, when you ask people to spend that kind of money, you can expect a few folk to demand ready access to the project and its results.

Well, get ready for all the Kepler you can handle. This week NASA will be releasing a second big data dump from the spacecraft, including tons of raw data plus readings from 400 of the most promising planetary candidates ID’d by the Kepler team.

Even better, a project called Zooniverse recently built a website called Planet Hunters to help members of the public sift through Kepler’s raw data and identify whole new worlds.

True, flipping through the Kepler data won’t be like looking at Hubble’s greatest hits. Kepler collects light curves from stars, and finding planets involves looking for dips in starlight that happen when planets transit—or pass in front of—their stars, from Kepler’s perspective.


Light curves from Kepler’s first five discovered planets.

—Picture courtesy NASA/Kepler Mission

But think of the glory if you find the light curve that reveals Earth 2.0 …

As far as NASA is concerned, an object needs to transit its star three times before they’ll consider it a candidate for planetary status. Then comes a lengthy process of calculations and secondary measurements to make the confirmation.

Luckily, the field is still ripe for finding the first true analog of Earth. So if you have ambitions in that direction, there are a few things you can search for among Kepler’s gatherings:

It needs to be the right mass and size for the planet to be a rocky world.

It need to orbit in the so-called Goldilocks zone of its star—just the right distance for the star’s heat to support liquid water on the surface.

It shouldn’t be tidally locked, or one side will always face the star, creating a world that’s half red-hot melted, half frozen wasteland.

The star should be relatively quiet, or massive solar flares will wipe away any protective ozone and fry chances for surface life.

And that’s just the stuff that Kepler can help us determine about a given planet. At the distances involved, the probe can’t tell you if an alien world has a magnetic field, a decent atmosphere, actual water bodies, and a dearth of ravenous bugblatter beasts.


An artist’s rendering of the planet Kepler-10b, the smallest exoplanet found so far.

—Picture courtesy NASA/Kepler Mission/Dana Berry

Of course, even if you find a planet in Kepler’s database, there’s no guarantee it’ll be an Earthlike world. The nine found so far are gassy planets like Jupiter and Neptune.

There’s also the chance someone’s beat you to the punch. The Kepler team released a first data dump last June, which Zooniverse used to kick-start the Planet Hunters site.

The thousands of people working on a month’s worth of data have so far found 90 candidate planets that are now awaiting followup by the Kepler team.

This week’s dump includes an additional three months of data, quadrupling your chances of finding new planets.

So get out there, people, and find me that retirement destination of my dreams…


—Base image courtesy NASA/Kepler mission/Dana Berry

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