A group of astronomers has developed a new computation method to examine exoplanets and determine whether they could host complex life, as we know it. According to their estimate, published in the journal Challenges, 100 million planets in the Milky Way could support complex life forms, beyond the microbial level. That does not mean, however, that they all do.

The computation method is known as the Biological Complexity Index (BCI). The researchers surveyed more than 1,000 known planets and used a formula that takes into account a planet’s density, temperature, chemistry, age, substrate (liquid, solid or gas) and its distance from the nearest star.

The BCI evaluation showed that only one to two percent of the planets had a rating higher than Jupiter’s moon Europa. While that number is low, there are an estimated 10 billion planets in the Milky Way. That means that there are approximately 100 million planets in the galaxy which could have life.

So, with 100 million planets capable of supporting life, are we likely to meet extraterrestrials soon? The answer is probably not. To begin with it is extremely unlikely that there are that many planets that actually host complex life.

“This study does not indicate that complex life exists on that many planets. 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,” said the paper’s authors Alberto Fairén, Cornell research associate; Louis Irwin, University of Texas at El Paso (lead author); Abel Méndez, University of Puerto Rico at Arecibo; and Dirk Schulze-Makuch, Washington State University, in a statement.

Even if we assume that many of those planets host complex life forms and even if we could visit, it might not be possible for us to communicate with them.

“Complex life doesn’t mean intelligent life – though it doesn’t rule it out or even animal life – but simply that organisms larger and more complex than microbes could exist in a number of different forms. For example, organisms that form stable food webs like those found in ecosystems on Earth,” the researchers explain.

Getting to planets which host complex, intelligent life is no small challenge in itself. Of the planets examined by researchers, the closest one which could host complex life is Gliese 581. That planet is roughly 20 light years away.

“It seems highly unlikely that we are alone. 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,” said the researchers.

However, there is no reason to give up hope. Today, NASA unveiled a design for what a warp drive ship might look like.