CAJ 2 - Planetary Science - The Kepler Mission

My first step towards the exploration of the Universe is a NASA mission that provides us with the most recent discoveries that were considered to be science-fiction but are now scientific reality.

The Kepler Mission is one of the most important ongoing missions in planetary science. The main purpose of the Kepler Mission is to find Earth-like planets in the extrasolar system. This means, planets that orbit stars outside of our solar system. Basically this mission is supposed to find our new home. It is a real challenge to find an Earth-like planet, even in the extrasolar system. The conditions needed for living organisms are many: a solid surface, the right temperature, liquid water, an atmosphere that provides air to breath. All these conditions have to be present at once. As the chance for a planet being at exactly the right distance from it's star and being composed of the right substance and material and being Earth-sized, is very low, scientists have  to work  hard to find a planet that fulfils all of these criteria and is thus habitable.

The main device of this mission is the Kepler Telescope. The Kepler Telescope was launched in March 2009 and the initially planed lifetime was three and a half years. As the noise while progressing the data from the incoming photons of the stars was greater than expected, the mission will last longer than originally expected. If the telescope remains intact, the mission will be funded till 2016. The telescope has detected 961 extrasolar planets in more than 76 stellar systems. All of these planets vary in size, composition and mass.

The telescope operates with a photometer (device to measure light intensity). While orbiting the Sun, the photometer points to one direction in the northern constellation of Cygnus, Lyra and Draco. This is right next to the well-known Milky Way.
The squares on the picture show the field of view the telescope analyses permanently.

The photometer measures the light intensity of these stars in that field of view, and if a planet orbits the star, then the brightness of the star changes. This change in light intensity is detected by the photometer. The
phenomenon when a planet orbits the star is called transit.  The size of the planet can be calculated by the time it takes the planet to orbit the star and by the decrease in brightness that is detected by the photometer. By knowing the orbital size and the temperature of the star, the temperature of the planet can be calculated. This is crucial, as the Kepler Mission searches for habitable planets and by this calculation it knows which stars are worth further analyzing.

The telescope has a 0.95 meter diameter which is the already mentioned photometer. It has an exceptionally large view of 105 square degrees. A normal telescope has a field of view of 1 square degree (square degree is a measure similar to degree that helps measuring parts of a circle but square degree is used to measure parts of a sphere).  By providing the telescope with such a large diameter, it is capable to observe a very big field of view. The telescope is permanently looking at more than 100.000 stars and simultaneously analyzing the incoming data.

The telescope and the team working on this mission, have made many new discoveries. For example, planets orbiting two suns like in Star Wars, aren't fiction anymore but reality. Scientific reality.

Further discoveries and information about the Kepler Mission will follow.
Stay tuned.

Resources:
http://kepler.nasa.gov/
http://en.wikipedia.org/wiki/Kepler_(spacecraft)
https://www.youtube.com/watch?v=IyjbJ3Rw7Cs
https://www.youtube.com/watch?v=Q86E2abw4AY