 |
| NASA/JPL-Caltech |
Exoplanets are one of the most fascinating topic in astronomy. The sci-fi movies were flooded with the references of exoplanets way before their existence was even confirmed!
The first possible detection of an exoplanet was noted way back in 1917. But, the first confirmation was made in 1992. The discovery took the world by storm. Since then the world has never stopped, year after year new planets were discovered and as of 1 February 2020 the tally stands at 4173!
Apparently universe has always something new to show us and exoplanets just proved it... Planets far massive than Jupiter orbiting their star so close that we never even imagined, Sub-Neptunes, Super-Earths were a lot common that we even thought of.
And with all this we even detected planets in the habitable zone of their host star, were liquid water and potentially life can exist!!
These are the exoplanets that can potentially host alien LIFE..... the countdown begins......
5. TRAPPIST-1d :
 |
| NASA/JPL-Caltech |
22 February 2017, astronomers surprised the world when they announced discovery of a hole bunch of planets in the habitable zone of the ultra-cool red dwarf star Trappist-1 located some 40 light years from us. It consist as many as six planets in the optimistic habitable zone!!...("take your time to digest this....")
Trappist-1d is located in the inner part of the habitable zone of the host star. It orbits the star in whooping 4.05 days(97 hours)! Though it is super-close to the host star it receives just a little more light than Earth.
Early climate models of the planet suggest that it may suffer runaway green house effect, but, with some refined parameters it may not be the case. If the planet has Earth like atmosphere, it can be hotspot for alien life. Due to tidal heating, the planet can have oceans upto 250 times as massive as that of Earth's. Trappist-1d has one of the highest Earth Similarity Index of 0.91.
Trappist-1d is located in the inner part of the habitable zone of the host star. It orbits the star in whooping 4.05 days(97 hours)! Though it is super-close to the host star it receives just a little more light than Earth.
Early climate models of the planet suggest that it may suffer runaway green house effect, but, with some refined parameters it may not be the case. If the planet has Earth like atmosphere, it can be hotspot for alien life. Due to tidal heating, the planet can have oceans upto 250 times as massive as that of Earth's. Trappist-1d has one of the highest Earth Similarity Index of 0.91.
4. Gliese 667Cc :
 |
| ESO |
Ever dreamt of getting up in morning and seeing three bright stars in the sky.... this is the place for you!
Gliese 667Cc is a planet orbiting its host star which itself is a member of a triple star system about 23.62 light years from us. It is a super-Earth with radius about 1.5 times that of Earth and orbits in the damn middle of habitable zone of the host star, taking just over 28 days to complete one orbit.
But, the planet is tidally locked to its host, which means one side is always facing the star and the other in eternal darkness....BUT, it can still contain a big strip of land between these extreme regions called the Terminator Line where conditions can be very suitable for life to evolve.
If the planet has a good atmosphere then it can pretty well conduct heat around the planet and the dark side can have warm temperatures. The equilibrium temperature of the planet is about 4.3°C, making it warm and maybe a good place for your sunbath......(super maybe)..
However, due to its highly eccentric orbit the tidal forces on the planet are way more than on Earth, which may reduce its chances of habitability.......still it is good candidate for study.
After its discovery, a mission called Breakthrough Starshot was announced which will take a army of miniature probes which will be propelled using ground based lasers and can reach upto 20% the speed of light! It is founded by Yuri Milner, Stephen Hawkings and Mark Zuckerberg and expected to be launch around 2036. For more info click here.
.jpg)
However, due to its highly eccentric orbit the tidal forces on the planet are way more than on Earth, which may reduce its chances of habitability.......still it is good candidate for study.
3. Proxima Centauri - b :
This was a ...EUREKA... moment for me when the astronomers announced in August 2016 that the closest star to us actually is home to a planet in the habitable zone!!!
Proxima Centauri is red dwarf star closest to Sun at a distance of just 4.2 light years. It is a member of triple star system.
Proxima Centauri-b is a super-Earth orbiting the host star in just over 11 days. It is subjected to solar winds 2000 times stronger that we experience here on Earth. This will likely rip-off any atmosphere it may contain. It is tidally locked to the host just like Gliese 667Cc and it may also contain a Terminator Line. In order to retain its atmosphere Proxima Centauri-b must have a very strong magnetic field. Considering it has a atmosphere similar to that of Earth, the side facing the star can be permanently ice-free with temperatures warm enough to host life.
Proxima Centauri is red dwarf star closest to Sun at a distance of just 4.2 light years. It is a member of triple star system.
 |
| ESO/M. Kornmesser Artistic impression of surface of Proxima Centauri-b |
Proxima Centauri-b is a super-Earth orbiting the host star in just over 11 days. It is subjected to solar winds 2000 times stronger that we experience here on Earth. This will likely rip-off any atmosphere it may contain. It is tidally locked to the host just like Gliese 667Cc and it may also contain a Terminator Line. In order to retain its atmosphere Proxima Centauri-b must have a very strong magnetic field. Considering it has a atmosphere similar to that of Earth, the side facing the star can be permanently ice-free with temperatures warm enough to host life.
After its discovery, a mission called Breakthrough Starshot was announced which will take a army of miniature probes which will be propelled using ground based lasers and can reach upto 20% the speed of light! It is founded by Yuri Milner, Stephen Hawkings and Mark Zuckerberg and expected to be launch around 2036. For more info click here.
2. Kepler-442b :
Kepler-442b is a super-Earth in the habitable zone of Kepler-442 about 1,206 light years from us. Its equilibrium temperature is about -40°C, but, the surface temperature can be warm if it has a good atmosphere producing greenhouse effect. Its surface gravity is predicted to be about 1.3 times that of Earth.
Kepler-442b orbits its host star roughly every 112 days. It is located just outside the point where it would have been likely tidally locked. Being close to the star its rotational period can be weeks or even months.
Kepler-442b is considered to be a Super-Habitable Planet. Super Habitable planets are those which can develop life even more diverse and complex than we see on Earth. So, it can be even more habitable than Earth! A big candidate for extraterrestrial life.
Kepler-442b orbits its host star roughly every 112 days. It is located just outside the point where it would have been likely tidally locked. Being close to the star its rotational period can be weeks or even months.
Kepler-442b is considered to be a Super-Habitable Planet. Super Habitable planets are those which can develop life even more diverse and complex than we see on Earth. So, it can be even more habitable than Earth! A big candidate for extraterrestrial life.
1. Trappist-1e :
 |
Here comes the big one. Yes, two planets of the same star system in the top 5!
Trappist-1e is just next door to Trappist-1d. It is the most Earth like planet as of now with a Earth Similarity Index of staggering 0.95! It is nearly Earth sized and yes you guess this right - in the habitable zone. It orbits the host star in every 88 days and it is likely tidally locked. But it can have a big patch of the Terminator Line between the extreme hot and cold region. The planet can have even more region habitable provided it have a atmosphere thick enough to transfer heat throughout the planet.
It is one of the most Earth sized world with 91% the radius of Earth and surface gravity of 0.93g.
Its host star Trappist-1 is a super-cool red dwarf which has a life span of astounding 4-5 trillion years!! And it can be one the last remaining stars in the universe when its life ends. It is by far one of the best place where future colonist can go when the solar system will near its end...
A quick info... - Panspermia is a hypothesis that life can exist on many planets where it is actually taken there by meteors, asteroids, comets, dust, etc. It is also considered that life on Earth may have came through panspermia between Earth and Mars...(though, it is debatable.).
The planets of Trappist-1 system are so close to each other that likelihood of interplanetary panspermia is 2000 times more than that of Earth and Mars!! So if life sprouted on one of the planets in the system then it may have traveled the nearby planets. The planets are so close that one can even see other planets in the sky with naked eye like we see the moon if the conditions are right!!!
So, this was my Top 5 list of exoplanets with potential alien life.
What are your Top 5 exoplanets with life? Do share in the comments down below.
0 Comments