Kepler Space Telescope’s study
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In News:
- According to US space agency NASA, our Milky Way galaxy is filled with 300 million potentially habitable planets.
News Summary: Kepler Space Telescope’s study
- NASA’s Kepler Space Telescope spent nine years till 2018 on a planet-hunting mission in the Milky Way.
- Kepler had already found billions (100-400 billion) of planets, but it was known that not all of them were “habitable”.
- Habitable planets are rocky planets capable of supporting liquid water on their surface.
- Scientists around the world studied Kepler’s data for years to understand how many of the planets in our galaxy were habitable.
- Now, a study published in The Astronomical Journal, it was revealed that there are at least 300 million potentially habitable worlds in our galaxy.
- Some of these planets could be close enough to be considered “interstellar neighbors” — the closest is around 20 light-years away.
About: The Study
- The study was a global collaboration between NASA scientists who worked on the Kepler mission, and researchers from international agencies ranging from Brazil to Denmark.
- A lot of factors that influence whether a planet can support life, including its atmosphere and chemical composition. However, the researchers in this study focused on a few basic requirements.
- They looked for stars similar to our own Sun in age and temperature, so it wouldn’t be too hot or active.
- They also looked for exoplanets with a similar radius to Earth, and singled out those that were likely to be rocky.
- They also took into consideration each planet’s distance from its star, that are not too close or too far.
- After calculating these factors, researchers used a conservative estimate (lower end estimate) that 7% of Sun-like stars could host habitable worlds. But the rate could be as high as 75%.
Way ahead:
- NASA and other space agencies will continue to refine the estimate in future research, which will help shape plans for the next stages of exoplanet discoveries and telescopes.
- Currently, NASA’s TESS mission is the latest planet-hunter seeking out exoplanets.

About: Galaxy
- A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems.
- A galaxy is held together by gravity.
- Planet Earth is part of a planetary system called the solar system, which is a small part of the Milky Way Galaxy.
About: Milky Way Galaxy
- The Milky Way galaxy is a large barred spiral galaxy. All the stars we see in the night sky are in our own Milky Way.
- Our galaxy is called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area.
- There are many planetary systems like ours in the galaxy, with planets orbiting a host star. By some estimates, Milky Way is made up of approximately 100 billion stars.
- Our solar system is located in an outer spiral arm of the Milky Way galaxy.