EXOPLANETS

1. Context

2. Key Points

• Located just 41 light-years away, the planet orbits very close to a red dwarf star and completes a full orbit in just two days.
• Researchers hope that in the coming years, owing to the Webb telescope’s advanced capabilities, they will be able to detect more Earth-sized planets.
• So far, most of the discovered exoplanets are similar to Jupiter as Earth-sized planets are much smaller in size and harder to discover with older telescopes.

3. About exoplanets

• Exoplanets are planets that orbit other stars and are beyond our solar system.
• According to NASA, to date, more than 5,000 exoplanets have been discovered.
• Scientists believe that there are more planets than stars as each star has at least one planet orbiting it.
• Exoplanets come in a host of different sizes. They can be gas giants bigger than Jupiter or as small and rocky as Earth.
• They are also known to have different kinds of temperatures boiling hot to freezing cold.

4. Studying exoplanets

• Studying exoplanets not only broadens our understanding of other solar systems but also helps us piece together information about our own planetary system and origin.
• However, the most compelling reason to learn about them is to find the answer to one of the most profound and thought-provoking questions of humankind are we alone in this universe?
• In a bid to understand the characteristics of an exoplanet, researchers look for its mass and diameter along with determining if it is solid or gaseous or even has water vapour in the atmosphere.
• Another important element of the study is finding out the distance between an exoplanet and its host star.
• This helps scientists determine if a discovered world is habitable or not.
• If an exoplanet is too close to the star, it might be too hot to sustain liquid water.
• If it’s too far, it might only have frozen water.
• When a planet is at a distance that enables it to have liquid water, it is said to be in the “Goldilocks zone”.
• With the launch of the Webb telescope, scientists believe that they would now be able to better study exoplanets as it is the only telescope that is capable of characterising the atmospheres of Earth-sized planets orbiting distant stars.

5. Discovery of exoplanets 

• Discovering exoplanets is quite tough as they are small and hard to spot around their bright host stars.
• Scientists rely on indirect methods, such as the transit method, which is “measuring the dimming of a star that happens to have a planet pass in front of it”.

6. Red dwarf stars

• As mentioned before, the newly discovered exoplanet orbits around a red dwarf star.
• Such types of stars are the most common and smallest in the universe.
• As they don’t radiate much light, it’s very tough to detect them with the naked eye from
  Earth.
• However, as red dwarfs are dimmer than other stars, it is easier to find exoplanets that surround them.
• Therefore, red dwarfs are a popular target for planet hunting.

For Prelims & Mains