Sci-Fi & Pi(e)

Danica:
So Kepler-

Melanie:
Who's Kepler?

Danica:
Well, he's a... ok, no, I'm
talking about the satellite.
You know the one they launch-
ed yesterday that's supposed
to head toward the sun?

Matt:
Yea, so that it can orbit
the sun and take pictures
of the other side and get
more complete images of
the universe.

Melanie:
So we can see the stuff
on other side of the sun?
Can't we do that... like,
once year? Every year?

Matt & Danica:
Oh yea...


And so I set out to find a sufficient response to Melanie's query. For those of you living under a rock (or in the process of indoctrination to all things nerdy - particularly the particulars of all things outer space), the Kepler Mission launched last Friday, March 6th, sending a powerful telescope able to "detect the dimming of a porch light as somebody passes in front" on Earth from its position trailing the planet.

"Kepler is a critical component in NASA's broader efforts to ultimately find and study planets where Earth-like conditions may be present," said Jon Morse, the Astrophysics Division director at NASA Headquarters in Washington.1

What makes Kepler so different from other telescopes we have floating in space (i.e. the Hubble)? The Kepler mission is not designed to gather broad data regarding the construction of our universe or even the details on what is within our own solar system. It is for the specific purpose of taking a census of the stars within our scope of viewing in order to determine whether or not habitable planets are a frequent occurrence in our universe.

The Kepler "telescope" is actually an instrument called a photometer. The ability to see someone walk in front of a porch light is mundane compared to the minuscule light differentiations the Kepler photometer is capable of detecting. The Kepler watches one area of space populated by a hundred thousand stars or so for a period of time; it is watching for the very slight decrease in the intensity of light from stars similar to our own Sun. This would indicate the passing of a planet in front of its star.

Finding stars similar to our own is the first step in finding planets similar to our own. The next, not possible with the Kepler, is finding orbiting bodies attached to those stars. When those planets are found, NASA will then need to determine the position of the planets relative to their stars to find out if they occupy the "Habitable Zone." If they do, they also need to support an atmosphere, have an iron core to create a magnetosphere, show signs of liquid water to facilitate carbon based life, and have a moon to stabilize the axis. NASA is not simply looking for a twin to Earth, these are simply prerequisites for habitable planets. It is true that some of these necessities can be bypassed if their purpose is served by other factors, but ultimately, the stipulations for the sustaining of liquid H2O are a difficult combination to achieve (or even speculate).

In the past year, a planet possibly fitting some of the innumerable requirements was found in a three-planet system orbiting Gliese 581.

As per Melanie's query regarding the "unique" orbit of Kepler... I have yet to find an answer. But if you ask me, I think John Morse just wanted to see if a photometer will really catch him walking in front of his porch light.