The Kepler Spacecraft

The fixed point of view for the Kepler Spacecraft

There are various ways in which humanity has begun detecting the presence of extrasolar planets, that is to say planets outside of our own solar system. Perhaps one of the most remarkable of these methods is that of the Kepler Observatory Spacecraft. It is a spacecraft like no other. It is a planet hunter. Its only job is to look out into the stars that surround us and detect candidate planets. It has been running for a little over three years now and it has turned up 2,321 candidate planets, 74 of which have been confirmed (as of this post). For most of us, this is difficult to imagine. Only 20 years ago or so, the only planets we knew about were the ones in our home solar system. Now, there are literally thousands of possibilities...planets upon planets out there in the galaxy around us. These happy discoveries still stun us, still excite our senses and the prospect of discovering even more planets in the future is very promising.

Observing these exoplanets is not an easy task. They are not immediately detectable, or even visible, from our star system. The Kepler Observatory uses the Astronomical Transit Method in order to infer an exoplanet's existence. This consists of observing a star's total amount of emitted light, measuring it and watching for changes in that amount of light. Noticeable and perhaps regular fluctuations can be an indication that a planet is passing in front of its star relative to our position in space. This could indicate an orbiting planet, which would block a detectable amount of light in regular intervals. The longer that Kepler observes a star, the greater the chance that a planet will show itself. Naturally, longer observations are better than short ones.

In order to make these planetary detections, Kepler must maintain an orbit around the sun, not the Earth. Additionally, Kepler must point its photometer to a specific point in the heavens just outside the plane of our Solar System and off-center from the plane of our galaxy. This is done in order to minimize confusion from crowded clusters of stars on the galactic plane and planetary bodies, Kuiper belt objects or asteroids in our own solar system that could pass in front of Kepler's observational photometer. Furthermore, Kepler is focused permanently on a specific region of stars. Indeed, it has not changed from this one spot since its mission began. That's right...2,321 planetary candidates, 74 of which are confirmed, all come from just one spot in the sky. It raises the interesting premise that there is a much larger diversity of worlds out there than we previously thought. Imagine when we train Kepler or a Kepler-like observatory on a different region of the sky. The prospects are tantalizing. There is so much left to discover.

Kepler is first real key to unlocking the secrets of those worlds. NASA has recently approved an extension for Kepler's mission, extending the search for habitable world's until 2016. How many candidate planets will we have detected by then? 5000? 10,000? Meanwhile, have the number of detections peaked for this one spot in the sky? Time will tell.

For more information about the Kepler spacecraft and its mission, visit the official site.
Keep track of us for Kepler-related news and exoplanet confirmations in the future.