Fig 1: Milky Way
Have you ever thought that there were other planets like Earth in our galaxy? There are many conditions that need to be met in order for NASA to believe that the type of planet they find through their telescope can essentially sustain alien life or maybe even have life that we don’t yet know about. Discovery of the first true alien Earth is a long held dream of many astronomers. With the use of the Kepler telescope and the discovery of recent exoplanets indicates this may be possible, that we will find a planet like ours in the not too distant future.
The most determined planet hunter, which had taken over two decades in the making, is about to reveal what our galaxy has to offer astronomers. Every astronomers dream, is to expose alien worlds orbiting distant stars and to discover if any of them are a suitable home for extra-terrestrials.
Kepler is a NASA mission and was funded to answer one simple question. What fraction of stars in our galaxy harbor potentially habitable, earth-size planets? However there are also other questions that we may want to unveil once finding out our main question. That is, what is the prevalence of earth size planets in our galaxy, does nature make them efficiently? Are they everywhere or is our planet just a fluke made by our galaxy?
On March 6 2009, a space telescope is launched into space, which is designed to observe distant stars and to examine how common earth like planets are. The space craft detects planets indirectly, using a transit method, which is measuring how star light dims ever so slightly as one of its planets passes in front of it. Besides revealing the presence of a planet, the slight signature can also tell the size and orbit. Other measures are then used to determine if each planet discovered is in the habitable zone. That is the distance from the star where liquid water could exist on the surface of the planet.
Liquid water is basically found everywhere on Earth, it could be from the polar ice caps to high heat temperature areas, basically wherever water flows on Earth, it is certain that life can be found in the surrounding area.
Kepler is trying to find planets that are in the “Goldilocks Zone” I’m sure everyone has heard about the Goldilocks tale, where the porridge is too hot or too cold and so she finds the one that is just right. That is exactly what Kepler is trying to find in relation to planets. The criteria to be considered as an Earth like planet has to have a similar size to Earth, rotates around a sun-like star and is located in the Habitable zone which is also called the Goldilocks zone. If the planet is in this zone, it is possible that liquid water is present on this planet, which therefore means life!
Kepler had stared at a single patch of the Milky Way for four years, before its pointing system failed in 2013. NASA’s engineers have decided that Kepler’s prime objective had to be ceased as they failed to find a fix for the pointing system, meaning it could not be held still any longer for the telescope to gather anymore data. However Kepler did not fail in retrieving data as the telescope had cataloged thousands of exoplanet candidates, which means astronomers still have to go through huge amounts of data to sort through.