Intelligent alien life is most likely to be found in globular clusters on the fringes of our Milky Way galaxy. Astrophysicist Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics said Wednesday at the American Astronomical Society’s annual meeting that there are about 150 globular clusters in Milky Way, most of them orbiting along the outskirts of the galaxy.
Interstellar travel a possibility in these clusters?
Di Stefano said these clusters of stars are old and stable, a key requirement for any civilization. Moreover, there are so many stars clumped together that it would be easy for living beings to travel from one place to another to keep the advanced society going. Globular clusters hold about a million stars in a compact region just 100 light years across. Alak Ray, an astronomer at the Tata Institute of Fundamental Research in India, said the clusters are about 12 billion years old.
Researchers estimate that more than 70% of all stars in the universe are present in globular clusters. More stars mean there is a likelihood of more planets, and more possibilities for intelligent life to develop. Di Stefano said the first step was to find more planets in these clusters. So far, only one exoplanet has been located. Some in the past have argued that the clusters don’t contain large amounts of heavy elements necessary for planet formation.
Premature to say no planets in globular clusters
Di Stefano and Alak Ray said it was “premature to say there are no planets in globular clusters.” Though Jupiter-like gas giants prefer stars that are rich in heavy elements, rocky planets like Earth don’t have the same tendency. Astrophysicists said globular clusters are so far away, so planets could be hard to spot. Their theory states that if there are a lot of rocky planets in these clusters, they would be sweet spot for the evolution of intelligent life.
Of course, this is just a theory at this point. If there are civilizations inside a cluster, there is a greater possibility of interstellar communication. In a cluster, the average distance between two stars is estimated to be 20 times closer than Earth is to its nearest stellar neighbor. So, interstellar travel would take a lot less time. Though it is difficult to spot planets so far away, scientists may use radio observatories to pick up laser or radio broadcasts emitted by distant civilizations.