300 Million Potentially Habitable Earths | 07 Nov 2020

New analysis of data from Kepler Spacecraft shows a large number of habitable Exoplanets.

An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmation of detection of exoplanets occurred in 1992.

After analysing Kepler's data for two years, a team from National Aeronautics and Space Administration (NASA) estimated that there are at least 100 billion stars in the Milky Way, of which about 4 billion are sunlike.
If only 7% of those stars have habitable planets, a conservative estimate is that there could be as many as 300 million potentially habitable Earths (exoplanets) out there in the whole Milky Way alone.
The team calculated that at least one third of stars similar in mass and brightness to the sun have rocks like earth in their habitable zone.

The Kepler mission was named in honor of 17^th-century German astronomer Johannes Kepler, who discovered the laws of planetary motion.
The Kepler Mission was launched in 2009 on a three-and-a-half year mission to monitor 1,50,000 stars in a patch of sky in the Milky Way.
It was NASA’s first planet-hunting mission, it discovered more than 2,600 of around 3,800 exoplanets.
- It looked for tiny dips in starlight caused by an exoplanet passing in front of its home star.
Kepler’s formal goal was to measure a number called eta-Earth: the fraction of sunlike stars that have an Earth-size object orbiting them in the “goldilocks” or habitable zone, where it is warm enough for the surface to retain liquid water.
Kepler is succeeded by NASA's Transiting Exoplanet Survey Satellite, or TESS, which was launched in April 2018. TESS is the new planet hunter for NASA.