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OT?: NASA Launching Kepler Mission to Find Earth-like Planets

Mountain View scientists giddy over NASA's search for faraway planets

By Mike Swift

Mercury News

NASA's 2,300-pound Kepler spacecraft is scheduled to thunder into space
Friday atop a Delta II rocket on a mission to see hundreds of worlds
beyond our solar system. It may also forever change how humans see their
place in the universe.

For at least the next 3? 1/2 years, Silicon Valley will become a leading
center for the search for extraterrestrial life.

The $591 million Kepler mission, with its science work directed from
NASA Ames Research Center at Moffett Field, is NASA's first mission
capable of finding Earthlike planets orbiting around other stars. In the
process, Kepler is expected to reveal an unimaginable cornucopia of
worlds — planets more dense than lead, Jupiter-size gas giants so close
to their suns that their atmospheres are boiling away, massive rocky
"super-Earths" and, perhaps, blue water-worlds where beings somewhat
like us could be staring up at the night sky, wondering if they are alone.

This spacecraft won't be traveling to those faraway galaxies for
close-up glamour shots. Instead, it will be launched far beyond the
distorting atmosphere, into an orbit around the sun millions of miles
from the Earth, to measure minuscule fluctuations in starlight that
provide evidence of orbiting planets.

As the red digits in the countdown clock on the wall in the Kepler
team's headquarters dwindle to the final days and hours before launch,
the local scientists who have devoted not just years but decades to the
mission are feeling a mixture of giddy anticipation and hand-wringing
anxiety.

Earth-based astronomers have cataloged more than 300 planets outside our
solar system since the first "exoplanet" was discovered in 1993, but
most are giant gas planets that could not support life. The Kepler
scientists believe their spacecraft should at least double the number of
known planets, creating a galactic "census" that will prompt whole new
theories on how solar systems form. They count on discovering the bizarre.

It's also possible, they say, that they will find few or no habitable
planets like Earth, a finding that would suggest our life-supporting
planet is unique in the cosmos.

"We'd be surprised if we're not surprised," said Bill Borucki, the
principal investigator for the Kepler mission. "We're about to make the
next step in understanding our place in the universe."

Borucki, who lives in Sunnyvale, came to Ames in 1962 to work on the
heat shield for the Apollo space capsule. Reassigned after the moon
program, Borucki became one of the first to suggest, in 1984, that
planets outside the solar system could be detected by tiny changes in
starlight as a planet moved across the face of a star.

The Ames scientists began submitting proposals for the Kepler mission in
1992, but NASA rejected their proposals four times, before finally
approving one in 2001. The spacecraft was supposed to launch in 2005,
but budgetary and hardware problems forced delays. For the team, it's
been a long, long wait.

"It's an emotional roller coaster around here," said Natalie Batalha, a
professor of astronomy and physics at San Jose State University who
helped select which stars the mission would observe.

Borucki, a 70-year-old who speaks in complete paragraphs that can sound
simultaneously scientific and poetic, is anxious to pore over the data.
Colleagues say Borucki is best described by the word "persistent."

"I think we're all interested in the question, is there life out there?
And I think the first question to answer is, are there planets for it to
live on?" Borucki said in his office, sitting in front of a large
whiteboard crammed with mathematical equations. "It's the first step
toward answering, are there others out there like us?"

Future missions would more closely investigate faraway planets for the
chemical signature of life. But Kepler is a necessary first step.

The spacecraft is an extraordinarily sensitive light meter that will
continuously monitor about 150,000 stars, most of which are between 600
and 3,000 light years away, in the area of the constellations Cygnus and
Lyra. The spacecraft will be launched into interplanetary space in an
orbit around the sun, to avoid reflected light from the Earth and the moon.

Kepler will use "charged-coupled devices" (CCDs), similar to those used
in digital cameras, to measure the brightness of stars with a precision
of 20 parts per million, an accuracy not attainable through Earth's
distorting atmosphere. That's akin to measuring the change in intensity
of a car's headlight when a flea crawls over the light — and doing it
for 150,000 headlights at the same time.

In this case, a tiny variation in a star's brightness will indicate the
transit of a planet, and once Kepler is able to observe subsequent
transits, and those observations are confirmed by ground-based
telescopes, scientists will be able to chart the orbit, mass and density
of the planet — providing strong clues as to its makeup and whether it
could support life.

While the first indications of newly discovered planets should be
announced before the end of this year, they will be gas giants with
short orbital periods close to their stars — and therefore not
candidates to harbor life.

It will be three years, enough time for Kepler to observe three
planetary transits and for ground-based telescopes to confirm the find,
before NASA is able to announce the discovery of other Earthlike planets
— or their absence.

The 15-foot-long spacecraft is named after Johannes Kepler, the
astronomer who championed the idea that planets orbit around stars, and
who discovered the same mathematical laws of planetary motion that NASA
scientists will use to discover new planets outside our solar system.

"It's a human experience to look up at the night sky and wonder what's
out there, but also to have that feeling where you feel so small, so
insignificant. We speculate there might be other life out there, but up
until now it's been confined to the realm of science fiction, to 'Star
Trek,' " Batalha said. "We're taking this big step towards understanding
if life might be common in our galaxy."

Contact Mike Swift at (408) 271-3648 or at mswift@mercurynews.com.


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Steven L.
Email:  sdlitvin@earthlinkNOSPAM.net
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