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Kepler-452b is an exoplanet orbiting the G-class star Kepler-452. An exoplanet, or extrasolar planet, is any planet that orbits a star other than the sun. Exoplanets are not limited to any size, content makeup, or placement. Kepler 452b was identified by the Kepler space telescope, and its discovery was publicly announced by NASA on 23 July 2015.[1] It is the first potentially rocky super-Earth[2] planet discovered orbiting within the habitable zone of a star very similar to the Sun. With O type stars being the hottest stars, and M type stars being the coolest, G class stars, such as the sun, are in the middle when it comes to its temperature. Because of this, we know Kepler 452b’s distance from its star is in the habitable zone, or the zone where temperatures and climate is somewhat mild and there may be liquid water on the surface. This is exciting because most Earth like exoplanets revolve around a star that is much cooler or smaller than our sun. Kepler is kept in the Cygnus constellation in the Milky Way. Using the criteria of the Earth Similarity Index, it is the sixth-most Earth-like exoplanet known to date. The planet is about 1,400 light-years away from the Solar System; at the speed of the New Horizons spacecraft, about 59,000 km/h (37,000 mph), it would take approximately 26 million years to get there.[3]

Properties
The planet takes 385 Earth days to orbit its star, 20 more Earth days than Earth.[7] This also means that this world is only 5% further from its star than Earth is from the sun.[4] It is 60% bigger than Earth, and lies within the conservative habitable zone of its parent star.[5][6]

It has a probable mass five times that of Earth, and its surface gravity is twice Earth's, though calculations of mass for exoplanets are only rough estimates.[5] If it is a terrestrial planet, it is most likely a super-Earth with many active volcanoes due to its higher mass and density. The clouds on the planet would be thick and misty, covering much of the surface as viewed from space. From the surface, its star Kepler-452 would look almost identical to the Sun as viewed from the Earth.[7]

It is not known if Kepler-452b is a rocky planet or a small gas planet,[8] but based on its small radius, Kepler-452b has a reasonable chance of being rocky.[1] It is not clear if Kepler-452b offers habitable environments. It orbits a G2V-type star, like the Sun, with nearly the same temperature and mass and 20% more luminous.[4] However, the star is six billion years old, making it 1.5 billion years older than the Sun. Kepler 452 is thus at a much more energetic phase than the sun is. At this point in its star's evolution, Kepler-452b is receiving 10% more energy from its parent star than Earth is currently receiving from the Sun.[9] While this keeps the planet warmer, or more like Earth’s temperatures, it also means the star is more likely to die out quicker. Kepler-452b is a rocky planet, it may be subject to a runaway greenhouse effect similar to that seen on Venus.[10] This means that the Carbon Dioxide is being trapped under the atmosphere, causing the air to be toxic. This causes temperatures to rise, which may result in the possible liquid water evaporating. Although complete evaporation is a possibility, the size of Kepler 452b means a stronger gravitational force, so it will take much longer for the water supply to deplete. A down side to it having twice as much gravitational pull is the way this would affect humans-we would be, and feel, twice as heavy. This would also cause our bodies to adapt, making us be stockier and stronger, due to carrying around twice our weight. While liquid water on the surface would be a great find, scientists are still unsure if Kepler 452b is even a terrestrial planet.

Future Plans
In order to find new information on this possibly habitable exoplanet, scientists have created a new telescope called the James Webb telescope. This is scheduled to launch in October of 2018, and is 100 times more powerful than the Hubble telescope, making it possible to find new information on Kepler 452b. It will provide an atmosphere analysis on Kepler 452b, and we will then know how habitable this new world actually is.