Are there other Earths? Absolutely. It would be even more fantastic to this writer to consider only one Earth in the unverse. So have astronomers already discovered Earth II?
A recentlydiscovered planet is just the right Earth-like size, but it circles a red dwarf star, named Gliese 581. We don't think of Earth-like planets being found around red dwarf stars. The faint star in question is located 120 trillion miles (20.5 light years) from our Sun. The discovery has triggered speculation about a second Earth and the possibility of extraterrestrial life existing there.
The name Gliese 581 refers to the stellar catalog of nearby stars first compiled by the late German astronomer Wilhelm Gliese. The initial news report about the terrestrial planet, now called Gliese 581c-designated "c" because it's the third rock from its dwarf sun-triggered wild speculation by news reporters and scientists alike. I recall a careless National Public Radio talk show host who had this distant planet's surface covered with liquid water and crawling with lifeforms. Talk about jumping to conclusions!
So, let's pull back on the reigns of speculation and put this extrasolar planet in perspective-
There's still more that is unknown about Gliese 581c than is known; it's just too far away to know more about it. And it is very possible that the planet is deadly to life since we know little about the effects of solar radiation bombarding it: Gliese 581c is orbiting extremely close to a red dwarf star. Also, while astronomers consider Mars to be within our Sun's habitability zone, the red planet appears to be a lifeless body that can't sustain Terran life without artificial means.
Gliese 581c was discovered using the European Southern Observatory's telescope in Chile. This observatory uses a unique device that splits a star's light spectrum to reveal "wobbles" in different wave lengths. Hence, the wobbles revealed the existence of planet Gliese 581c.