Do scientist think there is an Earth like planet and if so will it have “life”?

  The astronomers have discovered many planets that are likely to have life. They are called exoplanets because they are outside our solar system.

Single stars are the best hosts for planetary systems, but few multiple stars systems have planets orbiting them. The chemistry of stars is important, too. Stars rich in metals, elements that are heavier than hydrogen and helium are better for planetary systems than less evolved stars.

The scientists are looking for life friendly conditions. Planets must be quite small and rocky and orbit the star in a “habitable zone” which is a distance from the star where liquid water might form on its surface. If it is too close to the star it will be extremely high temperature and boil the oceans. The thick clouds would trap solar heat.

Scientists found over 4,000 exoplanets since 1995 according to NASA. More than half of them were discovered by Kepler space telescope. The Kepler Mission was a space observatory launched in 2009 by NASA over period of four years. It looked for Earth like planets near the habitable zone of Sun-like-stars. The mission results show many of these planets are similar in size to Earth. These are the most Earth-like planets.

Earth’s seven sisters (TRAPPIST-1)

Seven-planet system 40 light-years away from Earth, orbiting the parent star, known as dwarf star, called TRAPPIST-1. Three of these rocky planets support oceans on their surface. At least six inner planets in the system are similar in size and temperature to Earth. They are so close to Earth that scientists could be able to probe the planets atmospheres.

Kepler-186f

It was found in 2014 in the habitable zone. The planet orbits a red dwarf star about 500 light-years from Earth and it takes about 130 Earth days to go around it. This planet also exists in a stable environment and its not big enough to form the massive atmospheres seen on giant gaseous planets. But this planet is too far away to have its atmosphere probed for now.

Kepler 22b

It was the first Earth like planet outside the solar system discovered in 2011 by the Kepler space telescope. It is 2.4 times larger than Earth and orbits a star similar to our sun. It takes 290 Earth days to orbit its star, similar to Earth’s 365-days year. The average surface temperature is 22 degrees Celsius. This planet is bigger than Earth and scientists think that it could be covered with an ocean. However, because it is located 600 light-years away from Earth and it would be too difficult to study.