By Science Daily
There are some 100 million other places in the Milky Way galaxy that could support complex life, report a group of university astronomers in the journal Challenges. They have developed a new computation method to examine data from planets orbiting other stars in the universe.
Their study provides the first quantitative estimate of the number of worlds in our galaxy that could harbor life above the microbial level.
“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,” according to 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.
“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 in an auxiliary statement.
The scientists surveyed more than 1,000 planets and used a formula that considers planet density, temperature, substrate (liquid, solid or gas), chemistry, distance from its central star and age. From this information, they developed and computed the Biological Complexity Index (BCI).