The hunt for extraterrestrial life could be well served by investigating globular clusters, or the tightly-packed spheres that house millions of stars in an area averaging just 100 light-years in size, the Harvard-Smithsonian Center for Astrophysics (CfA) said on Wednesday.
CfA astrophysicist Rosanne DiStefano, who led the team of scientists conducting the research and presented their findings at the 227th meeting of American Astronomical Society (AAS) in Florida, explained that globular clusters could very well be “the first place in which intelligent life is identified in our galaxy.”
There are approximately 150 globular clusters in the Milky Way, with most of them orbiting at the edge of the system and many dating back to the birth of the galaxy roughly 10 billon years ago. For this reason, the stars found in these clusters contain fewer of the heavy elements required to create new worlds—leading many to believe that they are less likely to contain planets.
The fact that only one planet has ever been found in a globular cluster would seem to support those claims, but DiStefano and her colleagues believe that it is “premature to say there are no planets in globular clusters,” as exoplanets have been discovered orbiting stars containing less than 10 percent as many metals as our sun.
We have the capability to find such civilizations (if they exist)
Since the stars found in globular clusters tend to be faint red dwarfs, any potentially habitable planets forming around them would have to have close orbits to be in the so-called Goldilocks zone and be capable of supporting life. This would be a good thing, the researchers say, because it would protect them from stellar interactions from other stars in the dense cluster.
“Once planets form, they can survive for long periods of time, even longer than the current age of the universe,” DiStefano explained. If a habitable planet were to form in a globular cluster and survive for several billion years, there would be plenty of time for any life existing there to grow and evolve. Such life could theoretically develop intelligence and form civilizations.
These civilizations, were they to exist, could be surprisingly easy to find. The closest star found in a globular cluster is just one trillion miles away from Earth, which may sound like a lot, but is 20 times closer than the nearest non-cluster star. Communicating with and exploring such a place would actually be easier, the research team said.
“Sending a broadcast between the stars wouldn’t take any longer than a letter from the U.S. to Europe in the 18th century,” said DiStefano. “Interstellar travel would take less time too. The Voyager probes are 100 billion miles from Earth, or one-tenth as far as it would take to reach the closest star if we lived in a globular cluster. That means sending an interstellar probe is something a civilization at our technological level could do in a globular cluster.”
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Feature Image: NASA
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