Super-Earth

Only a few decades ago, if you said in public that life outside Earth was not just possible, but probable, people would laugh at you and talk behind your back.  Thanks to the advances in science, we’re able to see much further than ever in the history of mankind and collect some interesting facts about the subject.  Have you ever heard about super-Earths?

Astronomers working with the European Southern Observatory's (ESO) HARPS instrument have stated and estimation that, only in our galaxy, there are tens of billions of rocky planets not so much bigger than Earth orbiting red dwarf stars within the habitable zones (the area in a star system where liquid water can exist on a planet's surface) of those relatively cool stars.

Being in the habitable zone doesn’t necessarily mean that the planet has a perfect atmosphere or temperature; some may be too hot; others too cold, and the mass of the atmosphere can be really tricky in order to provide the essential means for the creation of life.

New observations indicate that 40% of all red dwarfs have rocky planets orbiting in their habitable zones.  Our own sun is a hotter G V, or yellow dwarf, star and is more than twice as massive as a red dwarf.

There are different types of stars known in the universe.  Because about 80% of stars in the Milky Way are red dwarfs (also referred to as M-class stars), this leads to the conclusion that tens of billions of rocky planets exist in habitable zones in our galaxy.

However, the planets called super-Earths have a better chance of supporting life than planets Earth-sized, and they can have up to 10 times the mass of our planet.  As scientists have also stated that every star in our galaxy, the Milky Way, has at least one planet in orbit around it, we’re able to get for the first time an idea of how many super-Earths might exist out there.

Fortunately, a great number of these exciting planets are relatively nearby neighbors: estimates suggest that there are 100 super-Earths in habitable zones around stars 30 light years or less from us, which is, in cosmological terms, really close.

Sara Seager, a professor of planetary science and physics at Massachusetts Institute of Technology, says: "We are sure, though, that because there are billions of stars in our galaxy alone, and because planet formation is a random process, many stars will end up with potentially habitable planets."

Now, the next quest is the study of their atmospheres and search for life – although Stephen Hawking has a very persuasive point of view about that; aliens almost certainly exist but humans should avoid making contact because, in his words, “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans."

He explained: "We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet."  Draw your own conclusions...