Are we alone in the Universe? This question has been asked for years with no real answer. However, there is one thing I know for sure and that is you’re not alone if you are a giant piece of matter hurling through space. This happens to be the very mission of NASA’s Kepler satellite: To assure molten masses of minerals that there are others out there just like them.
Okay, so maybe that isn’t the exact purpose of the Kepler photometer, but it comes close enough. As many people have heard, Kepler recently discovered Earth-sized planets in the region around the Cygnus and Lyra Constellations. The satellite’s real mission is to find ‘habitable’ planets, which are defined as planets that are half the size to twice the size of our Earth for this mission. Obviously this is just one of the many conditions necessary for a planet to be habitable.
The Kepler photometer consists of a telescope that is pointed toward a group of stars and measures their brightness levels – at the moment Kepler is monitoring more than 150,000 stars! When a planet crosses (or transits) the star in the field of view of the telescope, there is a minuscule but measurable dip in brightness levels. If this dip in brightness happens at regularly defined intervals, then a new planet is believed to have been discovered. The planet’s orbit is then determined by how long it takes to transit the star. The planet’s size is calculated by the dip in the star’s brightness level while the planet is in transit, along with the size of the star. The last important factor contributing to a planet’s habitability is its temperature. This is derived from its orbit size (i.e. the distant the planet is from the star) and the star’s temperature.
While these newly discovered planets are similar in size to Earth, they are too close to the star they orbit, making them very hot and inhabitable. To this day, Kepler has helped discovered 35 planets that are about the size of Earth. Kepler will continue to assist the scientific community in understanding the Universe and discovering new planetary satellites.