Science & Technology
300 Million Potentially Habitable Earths
- 07 Nov 2020
- 2 min read
Why in News
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.
Key Points
- 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.
Kepler Spacecraft
- The Kepler mission was named in honor of 17th-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.
