Using a new computation method, Cornell University researchers found that the Milky Way may be hosting more than a 100 million life-supporting planets.
The search for extra-terrestrial life has been a constant endeavour among space enthusiasts and scientists. Of late, researchers are also trying to find other celestial bodies that are capable of supporting complex life, similar to life on Earth. Findings of a new study suggest that such scientists may not have to look too far. According to Cornell University researchers, the Milky Way may be hosting more than a 100 million life-supporting planets.
"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," authors of the study said in a press statement. "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."
For the study, researchers first developed a new computation method that took into consideration planet density, temperature, substrate (liquid, solid or gas), chemistry, distance from its central star and age. Researchers used this method to examine data from more than 1,000 planets orbiting other stars in the universe. Using this information, they created the Biological Complexity Index (BCI).
Researchers found that approximately 2 percent of stars in the Milky Way had a BCI rating higher than Europa, one of Jupiter's moons. Europa is speculated to have a subsurface global ocean that may harbor forms of life. By calculations, it is safe to say that Earth's galaxy has more than a 100 million plausible life-supporting planets.
"It seems highly unlikely that we are alone," the researchers said. "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."
Researchers also noted that these life-supporting planets are very far apart from each other, owing to the vastness of the Milky Way. The closest extrasolar system is called Gliese 581. It has two planets that may be capable of supporting life and is located 20 light years away from Earth. Gliese 581g is one of the planets. It has a mass that is three to four times that of the Earth. This exoplanet has come under scrutiny as other research teams cast doubts about its existence.
Findings were published online in the journal Challenges. The study received no external funding.
