On this post I will give a range of facts about exoplanets, which is the term for any planet outside of our solar system.
Did you know that exoplanets are also called extrasolar planets? And that so far 4,016 exoplanets have been confirmed? From the 4016 exoplanets confirmed, 1352 are 'neptune like', 1256 are 'super earth', 1241 are gas giants, 161 are terrestrial and just six of the exoplanets are unknown. Also, more than 22 percent of sun-like stars in different solar sytems have an earth-size planet in their habitable zone and orbiting it.
51 Pegasi B was the first exoplanet found to be orbiting a star that was like the sun, 51 Pegasi B was discovered in 1995. In our nearest stellar neighbour, Alpha Centuari, two small Earth-like planets have been discovered, one of which may actually be habitable. The question that has been pondered on for years, are we the only life in the universe, has started to be answered by scientists now that we have developed our technology it is started to be found out that it is highly unlikely that Earth as a planet is unique. We have started to think this because it is estimated that 10-20% of stars in the milky-way have an Earth-like planet orbiting them.
Proxima Centauri b
Proxima Centauri b is the closest known exoplanet to our solar system, at 4.24 light years away(40 trillion km, 25 trillion miles). While Earth orbits the sun every 365 days, Proxima Centuari b orbits its star, Proxima Centauri, only every 11.186 Earth days. Proxima Centauri b was discovered on 24 August 2016 and is around the size of Earth, but it has a composition like Neptune and a thick layer of hydrogen on its surface. The planet has a temperature of -39 degrees Celcius. (-38.2 degrees farenheit). (234.15 degrees kelvin). This exoplanet is not habitable.
Kepler-69c is an exoplanet that has a larger mass than Earth but smaller than Uranus and Neptune. Kepler is known as a 'Super-Earth'. Kepler-69c orbits Kepler-69, its star, every 242 Earth days so the year on Kepler-69c would appear much shorter tha the year on Earth. Its temperature is 275 degrees celcius. (527 degrees farenheit). (548 degrees kelvin). This exoplanet is completely uninhabitable.