“The very old, stable (star) populations, coupled with the very small distances between stars, might make it possible for civilizations in globular clusters to travel and possibly develop outposts at relatively short times”, lead author Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics said. Our own Milky Way Galaxy sports around 150 of them, each one containing anywhere from a hundred-thousand to several million stars crammed into volumes about 100 light years across. In contrast, our own star, the sun, formed only 4.6 billion years ago, and is made of more complex, heavier elements that were around at this later epoch. Planets orbiting dimmer stars would have to be placed much closer in order to be life friendly.
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Of course, no one knows if any civilizations have, in fact, developed in globular clusters but statistically speaking, Di Stefano thinks it’s a reasonable possibility.
With that said, there are those who argue that this view is far too pessimistic.
While planets the size of Jupiter are found around stars that contain heavy elements, earth-sized planets do not have any such conditions for their configuration in space.
Di Stefano stated that the foremost evidence of intelligent life in our galaxy is likely to be found in a globular cluster.
But according to a new computer model, such clusters possess a “sweet spot” where small stars can hang on to planets in their habitable zones, where temperatures are right for liquid water and perhaps life. A planetary system might get disrupted with a neighboring star that could wander too close.
Some of them go back as far as the genesis of the Milky Way. Though their age is a controversial subject, it also proves that if any civilizations were established, they had enough time for evolution and advancement. New computer modeling suggests that those stellar groups could be just the place to find some alien civilizations. Hard proof has yet to be found in any form. Scientists refer to this as globular cluster opportunity.
DiStefano and her colleague Alak Ray argue that exoplanets have been found around stars only one-tenth as metal-rich as our Sun and that “such planets could also be found in globular clusters”.
Di Stefano presented her theory Wednesday at the American Astronomical Society’s annual meeting in Kissimmee, Florida.
So far, from the globular clusters themselves … only silence. Even us, at our technological level, would be able to send interstellar probes if we were to live in a globular star cluster.
Astronomers might even spot free-floating planets through gravitational lensing, in which the planet’s gravity magnifies light from a background star. “It’s premature to say there are no planets in globular clusters” expressed Ray. Sending a broadcast “wouldn’t take any longer than a letter from the U.S.to Europe in the 18th century”, said DiStefano.
The close proximity of the stars would allow information or objects to travel between star systems much more quickly than in, for example, Earth’s part of the galaxy.
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A more interesting idea might be to seek out globular clusters with SETI search methods – looking for laser or radio broadcasts. In 2015, astronomers collaborating on the Ĝ (Glimpsing Heat for Alien Technologies, or “G-HAT”) search released the first results of their analysis of data from NASA’s Wide Field Infrared Explorer, or WISE.
