“When Seti first started in 50s and 60s, we didn’t even know if there were exoplanets,” she told reporters at the meeting.
“Now we can use the information that we’ve gleaned from other planet discoveries – and there are over 2,000 planets known today – to ask, is it likely that they’d be in globular clusters.”
“In this large region… planetary systems can survive, and yet it’s dense enough that it may facilitate interstellar travel.”
In fact, she added, these planets – if they do exist – could last even longer than the current age of the Universe, leaving ample time for intelligence and interstellar ambition to flourish.
Other researchers at the conference agreed that these were interesting observations, even if the notion of ancient, star-hopping civilisations was – of course – a provocative speculation.
“It holds together,” said Jessie Christiansen from the Nasa Exoplanet Science Institute at Caltech. “It’s very speculative, but I like the idea that because globular clusters are old, they’ve had more time.”
“Single-celled, simple life might develop quickly, but complex life – let alone intelligent life – seems to take a really long time,” she added, citing Earth’s natural history as an admittedly limited example.
“So you might need those tens of billions of years.”
Alan Penny, an astronomer at the University of St Andrews in Scotland and co-ordinator of the UK Seti Research Network, told the BBC: “I think it does lift globular clusters up, in the wish list of targets to search.”
But they remain very difficult targets, he added.
“They are still a very long way away. The nearest globular cluster is 400,000 light years away, whereas there are plenty of other, low-mass stars closer than that.”