First Light

Planet-Hunting / by Lee Billings /

Kepler is looking at the radiant clouds of stars clumped thickly along the plane of the Milky Way, increasing the mission’s chances of detecting planets.

The field of view for Kepler’s telescope is set: a star-rich patch of sky in the constellations Cygnus and Lyra. Credit: NASA/Ames/JPL-Caltech

At first glance the picture seems unremarkable — perhaps these are fabric swatches forgotten in a display case, now covered with accumulated dust. The truth is more awe-inspiring: Each speck of “dust” is light from stars in a patch of sky spanning 100 square degrees, between the constellations of Cygnus and Lyra. More than 4.5 million stars are captured here in the first image from Kepler, NASA’s new spacecraft designed to find Earth-like planets. Look closely — chances are another planet quite like our own lurks somewhere in this expansive view. And though you can’t see it, eventually Kepler will.

Kepler has a single eye, a telescope linked to the largest camera ever launched into space. It will stare unblinking for at least 3.5 years at this one region of the heavens, watching 100,000 promising stars for any “transits” — minute dips in light caused by the periodic passage of orbiting planets. The field of view lies along the galactic plane of the Milky Way where radiant clouds of stars are clumped thickly, increasing the total number of stars observed and the chances of detecting more planets.

Three transiting planets are already known to exist in Kepler’s field of view. All are “hot Jupiters,” worlds similar in size to Jupiter or Neptune that orbit inhospitably close to their host stars. Though their official names don’t exactly roll off the tongue — TrES-2, HAT-P-7b, and HAT-P-11b — they’ll become very familiar to the mission’s scientists and engineers, who will use them to calibrate the spacecraft’s instruments. But since Kepler will take unmatched measurements of these planets, they might still be the sources of major discoveries — slight statistical fluctuations in the timing of their transits could hint at accompanying moons or other non-transiting planets in their star systems.

This first image is just one in a long series of milestones. David Koch, Kepler’s deputy principal investigator, recalls planning for the mission with his colleague William Borucki back in 1992. Nine years passed before NASA approved the mission; it took eight more to construct and launch the spacecraft. Now Koch, Borucki, and the rest of their team are in the midst of a task that will define their careers, working feverishly to “commission” Kepler, preparing it for its first scientific observations in early May. After this the spacecraft will begin finding potential planets at a rapid pace, but the public won’t hear about most of them right away.

“There’s quite a bit of follow-up observing that we have to do,” Koch says. “When you have a candidate there are a lot of potential reasons that it could be a false positive.” Each possible planet that emerges from the data must be vetted and confirmed by observations from large ground-based telescopes, most of which already have packed schedules and limited availability, creating a potential bottleneck for the announcement of any discoveries.

Koch has already waited nearly two decades for this moment to come; taking a few more years to validate what may be one of this age’s greatest discoveries — other Earth-like planets in our galaxy — seems only sensible. When the time comes, he’ll be prepared with a ready visual aid.

“For the past five years, I’ve had Kepler’s star field covering one whole wall of our conference room ceiling to floor, assembled from six Palomar sky survey plates,” he says. “I already have three push-pins in the pictures where the three known transiting planets are. Right now I’m using red ones because they’re hot Jupiters, but I’m hoping I can push in some nice ‘pale blue dots’ soon.”

Originally published April 23, 2009

Tags research space

Share this Stumbleupon Reddit Email + More


  • Ideas

    I Tried Almost Everything Else

    John Rinn, snowboarder, skateboarder, and “genomic origamist,” on why we should dumpster-dive in our genomes and the inspiration of a middle-distance runner.

  • Ideas

    Going, Going, Gone

    The second most common element in the universe is increasingly rare on Earth—except, for now, in America.

  • Ideas

    Earth-like Planets Aren’t Rare

    Renowned planetary scientist James Kasting on the odds of finding another Earth-like planet and the power of science fiction.

The Seed Salon

Video: conversations with leading scientists and thinkers on fundamental issues and ideas at the edge of science and culture.

Are We Beyond the Two Cultures?

Video: Seed revisits the questions C.P. Snow raised about science and the humanities 50 years by asking six great thinkers, Where are we now?

Saved by Science

Audio slideshow: Justine Cooper's large-format photographs of the collections behind the walls of the American Museum of Natural History.

The Universe in 2009

In 2009, we are celebrating curiosity and creativity with a dynamic look at the very best ideas that give us reason for optimism.

Revolutionary Minds
The Interpreters

In this installment of Revolutionary Minds, five people who use the new tools of science to educate, illuminate, and engage.

The Seed Design Series

Leading scientists, designers, and architects on ideas like the personal genome, brain visualization, generative architecture, and collective design.

The Seed State of Science

Seed examines the radical changes within science itself by assessing the evolving role of scientists and the shifting dimensions of scientific practice.

A Place for Science

On the trail of the haunts, homes, and posts of knowledge, from the laboratory to the field.


Witness the science. Stunning photographic portfolios from the pages of Seed magazine.

SEEDMAGAZINE.COM by Seed Media Group. ©2005-2015 Seed Media Group LLC. All Rights Reserved.

Sites by Seed Media Group: Seed Media Group | ScienceBlogs | Research Blogging | SEEDMAGAZINE.COM