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PLANETS SIMILAR TO EARTH

5 APRIL 2017

 

 

 

It’s not an unknown fact that Earth is going to cease to exist at some point in the future. It’s just not likely it's going to happen in our lifetime but we can’t rule out the possibility since anything can happen. There are endless of possible ways our planet can be ruled as unlivable, from our sun dying to us falling into a black hole. Knowing all these can be a variable in our planet’s demise, scientist having been trying to find planets that have similar characteristics as Earth. Most of what scientist have found are to be compatible are exoplanets.

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What Are Exoplanets?

 

Exoplanets are planets that live beyond our solar system and are usually found surrounding another star. Thousands of exoplanets have been discovered in the past two decades mostly from NASA’s Kepler space telescope. These planets come with a variety of sizes, varying from planets smaller than Earth from planets twice the size of Jupiter.

 

Exoplanets were only recently scientifically proven to exist since the 1990’s, however astronomers were always convinced that exoplanets were always out there. Scientist made an Origin story for the creation of our Solar system. Basically, there was  protosolar nebula (a cloud of gas and dust)  that collapsed on it’s own gravity and formed the Sun and planets. When the nebula collapsed, conservation of angular momentum meant the soon–to–be–sun should have spun faster and faster but instead it started rotating slowly. Astronomers were left asking themselves why the sun rotates so slowly.

 

The sun would’ve had a very strong magnetic field, whose lines of forced reached out into the disk of swirling gas from where the planets would form. From these field lines connecting with the charged particles in the gas it made itself into an anchor abling the slowth of the forming sun’s spin and spinning up the gas that would eventually turn into planets. Most stars like the sun rotated slowly, so Astronomers inferred that since those suns had the same magnetic braking as ours, it meant a planet formation must’ve formed.

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This theory wasn’t always right, since the first two exoplanets that they discovered was surrounding a pulsar (a rapidly spinning corpse of a star that died as a supernova). So astronomers stopped restricting their search for exoplanets near stars similar to ours.

 The first proper discovery of an exoplanet was in 1995 when they found a planet with the mass of Jupiter that’s 20 times closer to the sun than we to ours. They named the Jupiter-like planet, 51 Pegasi b. They also found another Jupiter-sized planet around Gamma Cephei back in 1988 but since it’s orbit was so smaller than Jupiter’s scientists didn’t claim a definitive planet detection. 

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Artist's Rendition of Kepler-186f

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Habitable Planets

 

Today there are more than 1,000 exoplanets confirmed by one single telescope. The Kepler space telescope has hunted for habitable planets, since they became into orbit in 2009, for 4 years now. The telescope has discovered 1,284 new planets and out of all those only 9 are in the habitable zone of their star. Nearly 550 are possibly rocky planets roughly around the same size of Earth.

The Kepler telescope has revealed an abundance amount of terrestrial planets, but more importantly it has helped define a whole new class called as “Super-Earths”. Super-Earths are planets that are between the size of Earth and Neptune, some are even located in the habitable zone of their stars. Even though, some astrobiologist are going to back to the drawing boards to consider how life might develop on these planets.

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On July 23rd 2015, NASA announced the discovery of Kepler-452b, Earth's bigger, older cousin. This planet might be one of the contestants to be Earth 2, but scientists still aren't sure whether Kepler-452b has any oceans or continents similar to Earth's. Kepler-452b is about 60% larger than Earth, it's also 1,400 light years away from Earth in the constellation Cygnus.

A team of Astronomers on April 17 2014 discovered the first Earth-sized planet, Kepler-186f, orbiting the habitable zone of a star. The habitable distance from a star is where liquid might pool on the surface. That doesn't mean there's life on this planet, says Thomas Barclay, a scientist at the Bay Area Environmental Research Institute at Ames. He explains that the planet can be thought of as Earth’s cousin instead of its twin. Kepler-186f has many similarities and properties that resembles Earth. The planet is about 500 light years away and is also in the constellation Cygnus.

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Kepler-62e is a planet that is believed to be a water planet. It is concluded that the equivalent amount of distance to it’s sun is the same amount of distance that mercury is to ours. The planet is about some 1,200 light years away from Earth. It is about the same size that it is to Earth and is in the right region to it’s sun that it can be considered habitable. Even though it’s close to it’s star it’s still habitable since the the star it’s orbiting is way less dimmer than ours.

 

The planet is about 1.6 times bigger than Earth and orbits its red dwarf star for about once every 122 days. This planet is actually one out of two possible habitable planets in it’s system, the other possible habitable planet is Kepler-62f. These two planet are classified as a “Super-Earth” meaning that the planets are most likely to have the same  characteristics as Earth. Some scientist has started to think about how life on Earth might have even originated from Kepler-62e and Kepler-62f.

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Chart showing different Kepler planets

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These are only just the gist of how many suitable planets that astronomers have found to be the next possible Earth. There are hundred more planets that fit the description of being Earth 2.0 that I could go on and on, but I’ll save you the trouble and stop here. Now you can live on without worrying about the fact that Earth will one day die,we got it covered with many of backup planets.

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