PIX4573975: Super Terre - Orbital view of a Super - Earth - A red dwarf star emerge behind the limbe of a habitable exoplanet. The planet, a Super Earth is about twice as big as the Earth. Another planet is visible, in transit in front of the star. A red dwarf star emerges from behind the limb of a planet twice earth's size orbiting in the star's narrow habitable zone. An inner planet transits the sun's disk, Dixon, Don (b.1951) / Bridgeman Images
PIX4573697: Artist's view of the exoplanet Gliese 581c. - Artist's view of the exoplanet Gliese 581c. Gliese 581c, with a radius of 1.5 times that of the Earth, is the first exoplanet gathering the necessary elements to imagine the existence of a possible extra-terrestrial life. With a mass of 5 times that of the Earth, an average temperature of 0 to 40* C, this exoplanet rotates around its star in just thirteen days and is located 14 times closer to its star than the Earth is to the Sun., Dixon, Don (b.1951) / Bridgeman Images
PIX4571579: In the cloud of Oort - Illustration - Inside the Oort cloud - Illustration - The cloud of Oort is a vast body envelope orbiting well beyond the orbit of the planets of the solar system. Comets would come from that cloud. The Oort Cloud is a huge spherical cloud surrounding our Solar System. Extending about 30 trillion kilometers (18 trillion miles) from the Sun, it was first proposed in 1950 by Dutch astronomer Jan Oort. The vast distance of the Oort cloud is considered to be the outer edge of the Solar System where the Sun's influence ends. It contains billions of icy bodies and seems to be the birth place of comets, Dixon, Don (b.1951) / Bridgeman Images