It is estimated to have about 100 billion planets in the Milky Way galaxy. However, only one is known to have life, Earth. The Kepler space observatory telescope intends to answer humankind's ultimate question: Are we alone? Humans look to find life away from Earth because it would answer many questions about us such as Where we came from? and Why we are here? While scientists are optimistic that there is alien life away from home, they are yet to have found 'another Earth'. The Kepler telescope uses a very clever way to try to find a planet with life. It uses a method called transit. Transit is a planet detection method that detects the reduction of star's brightness. Here is a representation of what a transit looks like at a very high zoom. .
Figure 1. Detecting alien planet. [Photography]. Retrieved from Encyclopædia Britannica ImageQuest. .
http://quest.eb.com/search/132_1299822/1/132_1299822/cite.
When an exoplanet passes directly between its star and Kepler's line of sight, it dims a minuscule portion of the star's light. An exoplanet is a planet that is outside our Solar System. There have been thousands discovered and they range in size, temperatures, orbital periods and composition.
One exoplanet that could be a potential new home for humans is Kepler-442b. Kepler-442b is an exoplanet that is found in the habitable zone, or "Goldilocks" zone of a star that is approximately 1120 light years away (10.6 x 1015 km). Here is a diagram that shows the approximate Habitable zone of the star Kepler-442 and where Kepler-442b is compared to the zone.
Figure 2. Extrasolar planet kepler-442b [Image]. (2015). Retrieved from .
http://kepler.nasa.gov/Mission/discoveries/kepler442b.
That distance is equal to over 70 million times the distance from the Sun to Earth. Kepler-442b was confirmed to be an exoplanet on the 6th of January 2015 and was likely discovered 2-3 Earth years before. It has an orbital period (time to orbit around its star) of 112 days and a radius of approximately 1.