ANOTHER SOLAR SYSTEM WITH 7 EARTH-SIZED PLANETS FOUND – NASA Announcement on 22nd Feb, 2017


In one of the most exciting press conferences, NASA declared having found another solar system along with 7 earth-sized planets just 39 light years away! With 3 out of the 7 planets in habitable zone, this system has been found in the constellation Aquarius.

This TRAPPIST-1 solar system gets its name from its parent m-dwarf star TRAPPIST-1, and the planets around it are currently referred to as Trappist b-h. This is an m-dwarf star and is relatively much cooler and smaller now. One of the smallest known m-dwarf star!

WHAT MAKES THE DISCOVERY SO AMAZING?

These 7 planets are what we call exoplanets, i.e. planets orbiting a star outside our solar system! We (I mean NASA and the likes ofcourse!) have discovered many such planets in the past too. But what makes this discovery so great is that before this, NASA had found only around 2-3 exoplanets around a star!
These 7 planets are rocky, each of the size of Earth (approx.) and each supporting a possibility of existence of water and 3 of them in the habitable zone!

HOW WERE THEY FOUND?

In 2016, the 2 planets of this system were found by the Belgian operated telescope called Trappist located in Chile. Hence the star got its name. In 2017, NASA’s SPITZER Telescope with the help of ground based telescope found the other 5 planets.

HERE ARE A FEW FACTS WITH EXPLANATIONS TO UNDERSTAND THIS BETTER.

FACT WHAT DOES IT MEAN?
1. This is an M-dwarf star. It is a very small star than our Sun, having only about 11% the radius and 8% the mass of our Sun.
2. The Sun never rises or sets for these planets.
The planets are tidally locked!
The planets have their period of rotation and revolution same. This means that while one side of the planet always faces the Sun, the other side is always in the dark. This is also the case with our Moon because of which we see only one side of the moon from Earth.
3. One year is about 1- 20 Earth days long in this solar system. The period of revolution of these planets varies from 1-20 Earth days.
4. The system has 3 planets (Trappist e, f, g) in the Goldilocks zone! Three planets in this system namely, e,f,g can support life as they lie at a favorable distance from the Sun called the Goldilocks Zone.
5. Since the star is small, the orbits of these planets are much closer.
  • If you were to stand on one of the planets, you could see all the other planets in the sky. (as correctly represented by NASA’s poster.)
  • These planets hence naturally have a very small period of revolution.
6. This solar system is only 39 light years away!
  • If you were travelling at the speed of light, you could reach this system in 40 years.
  • If you were travelling in a super-fast jet, it would take you millions of years to reach.

However, NASA is leaving this journey on the future generations to undertake and currently it only wants to find possibility of life on these planets.

7. The distance between the planet e and Trappist star is only 5 percent the distance between us and the Sun. The Sun in this solar system would look about 6 times larger in the sky than what we see.

SO IS LIFE POSSIBLE ON THIS PLANET?

As per a core team member of NASA, the problem with m-dwarf stars is that during their young age, they are very volatile and active. This might have already burnt out any atmosphere expected to be present around these planets.
Further, the tidal locking poses a huge problem. Due to one side always facing the star, that side has temperatures soaring to high levels with the other side being extremely cool. Due to these extreme temperature variations, it makes it difficult for life to survive on such planets.

poster

WHAT’s THE PLAN AHEAD?

NASA is planning to continue the study of these planets using the Hubble Space Telescope. A lot of hopes are on the James Webb Telescope due to be launched in 2018. As it is expected that with JWT, we would be able to study the presence of essential life supporting compounds on these planets like Oxygen, Methane, etc.
SO WE’RE HOPEFUL AND CURIOUS BUT LET US SEE WHAT WE FIND THROUGH OUR TELESCOPES!

While existence of life is a big question, but existence of at-least a primitive life form is very much probable!

References:
NASA’s Live Press Release held on 22nd February.
https://exoplanets.nasa.gov/trappist1/
https://en.wikipedia.org/wiki/Spitzer_Space_Telescope
https://www.nasa.gov/multimedia/videogallery/

By:-
Aishwarya Girdhar
Educator
SPACE Foundation

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