21st April 2009 - Gliese 581 e is only 1.9 times the size of Earth [See related link]
They have discovered some hundred planets outside our Solar System. Whether some of them are similar enough to our planet to be called "an earth", is open to debate.They have discovered some hundred planets outside our Solar System. Whether some of them are similar enough to our planet to be called "an earth", is open to debate.They have discovered some hundred planets outside our Solar System. Whether some of them are similar enough to our planet to be called "an earth", is open to debate.They have discovered some hundred planets outside our Solar System. Whether some of them are similar enough to our planet to be called "an earth", is open to debate.
The first planet discovered besides Earth is Uranus. It was discovered by William Herschel in 1781.
The earth as planet was discovered by some of the ancient astronomers. Nicolaus Copernicus and Ptolemy are credited with provision of the initial information of the earth as a planet in relation to the solar system.
on planet earth
was..then it smashed into earth and created the moon was..then it smashed into earth and created the moon
earth
Earth...
It was actualy not too long ago. Scientists discovered it Wednesday morning, December 7th 2011.
Venus is often compared as Earth's "sister planet", being similar in size and internal composition.
Mars
The planet that has enough density to support the weight of a colony is Mars. Scientists have discovered that Mars is relatively similar to the conditions on Earth.
There is currently no confirmed sister planet to Earth. However, astronomers have discovered many exoplanets in other solar systems that share similar characteristics with Earth, such as being rocky and located in the habitable zone of their star.