Ancient Stars (and a Thought on SETI)

Recent discussions on the search for extraterrestrial intelligence (SETI) highlight the improbability of two civilizations developing simultaneously within a few light years of each other. Brian Lacki from UC-Berkeley emphasizes the need to consider temporal coincidences, as human technological society has existed for only a brief period compared to the 4.6 billion years of Earth's history. The Gaia mission has provided new insights into the ages of stars in the Milky Way, revealing that many nearby stars are older than previously thought. A study led by Samir Nepal at the Leibniz-Institut für Astrophysik Potsdam utilized machine learning to analyze data from Gaia, uncovering that the thin disk of the Milky Way began forming much earlier than 8-10 billion years ago, possibly as early as 4-5 billion years after the Big Bang. This suggests that ancient stars, particularly those with higher metallicity, could be promising targets for SETI, as they may host planets where life and technology could have developed over a longer timescale. The findings challenge previous assumptions about stellar formation and the potential for life in the galaxy, complicating the Fermi Paradox regarding the existence of intelligent civilizations.

- The likelihood of simultaneous civilizations developing near each other is extremely low.

- Gaia mission data reveals many nearby stars are older than previously estimated.

- Ancient stars may provide better SETI targets due to their potential for hosting life.

- The thin disk of the Milky Way may have formed earlier than previously believed.

- The findings complicate the understanding of the Fermi Paradox regarding extraterrestrial intelligence.