Researchers at Cambridge University have searched to see which planets could potentially sustain life, the way Earth does,  the Independent reports. 

The researchers found that the probability of life developing in any one planet is somewhat related to the type and strength of light that they receive from their star. The most exciting aspect of this development is that there is a limited range of planets that fall within this category, which means they are more likely candidates for Earth-like life than others. 

“This work allows us to narrow down the best places to search for life,” said Dr. Paul Rimmer, the postdoctoral researcher who was the lead author of the study published in the scientific journal Science Advances. “It brings us just a little bit closer to addressing the question of whether we are alone in the universe.”

Basically, if a star is giving off enough of the right kind of UV light, it could possibly be enough to support the basic chemicals needed for the beginnings of life as we know it on Earth. Some of the planets who give off such UV light also have the appropriate temperature for liquid water on their surface. Add that to the recent discovery of underground water reserves of liquid water on Mars, and any alien non-believers may start to rethink their position.

Of course, it remains possible that extraterrestrial  life has developed in ways entirely unlike how it has developed on Earth. However, this is the kind of life we know and have means of measuring, and a new development like this helps narrow the path. 

“I’m not sure how contingent life is, but given that we only have one example so far, it makes sense to look for places that are most like us,” Dr. Rimmer said. “There’s an important distinction between what is necessary and what is sufficient. The building blocks are necessary, but they may not be sufficient: it’s possible you could mix them for billions of years and nothing happens. But you want to at least look at the places where the necessary things exist.”