Apr 27, 2021 - Science

Astronomer Jill Tarter is on a search for extraterrestrial life

Photo illustration of Jill Tarter

Photo illustration: Annelise Capossela/Axios. Photo: Roger Ressmeyer/CORBIS/VCG via Getty Images

Astronomer Jill Tarter wants the search for extraterrestrial intelligence (SETI) to be taken seriously.

Why it matters: SETI as a scientific field has long played second fiddle to other, well-funded searches for direct and indirect signs of life — like NASA’s Mars program and the hunt for alien planets around distant stars.

What's happening: Instead of generally referring to SETI as a search for smart aliens, Tarter is focusing on the search for "technosignatures" — signs of technology like geoengineering or large structures in orbit from distant civilizations.

  • "We can't define intelligence, and we certainly don't know how to find it at a distance, directly," Tarter told me. "What we can do is to look for evidence of somebody else's technology that might be discernible over interstellar distances."
  • If scientists on Earth happen to discover those massive signs of intelligent civilizations, however, they were likely created by a more advanced society because anything scientists could pick up from this far away would need to be particularly large for researchers to see it.

Between the lines: By putting technosignatures in the same conversation as biosignatures — biological signs of life on other planets like Mars — Tarter hopes both searches will be able to play off of one another.

  • "The exoplanets and extremophiles are pointing out that there is a lot more potentially habitable real estate out there than we ever imagined," Tarter said.
  • She also added that "the next obvious question is are they inhabited by intelligent beings?"

The intrigue: In the U.S., SETI efforts have largely been funded through philanthropy.

  • Yuri Milner's Breakthrough Listen is the most high-profile example of a philanthropy-funded SETI project in recent years.
  • But relatively new, international radio telescopes — like China's FAST and South Africa's MeerKAT — have come online, with the search for alien life built into their DNA, potentially giving a boost to the search for technosignatures globally.
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