Milky Way Galaxy May Have 100 Million Planets that Could Support Life

Could other planets support life? It's likely, and there may be more in our very own galaxy than previously thought. Astronomers have found that there are about 100 million other places in the Milky Way galaxy that could support complex life.

The researchers surveyed more than 1,000 planets and used a formula that considered planet density, temperature, substrate, chemistry, distance from its central star and age. This gave scientists a good sense of whether the planet could potentially support life; from this, the researchers created the Biological Complexity Index (BCI).

The BCI calculation revealed that about one to two percent of the planets showed a BCI rating higher than Europa, which is one of the Jupiter's moons that's thought to have a subsurface ocean that could harbor life. In the end, they found that there was about 100 million plausible planets. That said, these are just possibilities.

"This study does not indicate that complex life exists on that many planets," said the lead authors of the new paper in a news release. "We're saying that there are planetary conditions that could support it. Origin of life questions are not addressed-only the conditions to support life."

In addition, complex life doesn't mean intelligent life. Yet it does show that it's very likely that some form of life exists in our very own Milky Way. In fact, one of the closest and most promising extrasolar systems, Gliese 581, is a mere 20 light years away. This system has two planets with the possible capacity to host complex biospheres.

"It seems highly unlikely that we are alone," write the researchers in a news release. "We are likely so far away from life at our level of complexity that a meeting with such alien forms might be improbable for the foreseeable future."

The findings are published in the journal Challenges.