SETI 2024 [Turnstile]

Regular readers of the column will recall my long-standing fascination with the scientific search for extraterrestrial intelligence (SETI). Last year I wrote about the American astrophysicist Frank Drake (1930–2022), who kick-started SETI in 1960 with his Project Ozma <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> and whose eponymous Drake equation <xref ref-type="bibr" rid="ref3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[3]</xref> has been used to estimate the number of observable civilizations in our galaxy. Recently, I browsed through a new crop of books devoted to SETI. They included <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars</i> <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> , by the Harvard astronomer Avi Loeb; <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Alien Earths</i> <xref ref-type="bibr" rid="ref4" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[4]</xref> , by Lisa Kaltenegger, the director of the Carl Sagan Institute at Cornell; and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">The Little Book of Aliens</i> <xref ref-type="bibr" rid="ref5" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[5]</xref> , by the physicist Adam Frank of the University of Rochester. Even a cursory perusal of these books makes one thing very clear. Not only are scientists going beyond Drake’s original vision of searching for “radio waves sent forth by other intelligent civilizations” <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> , but the current SETI discourse also employs many terms unfamiliar to the wider public. Here are a few of them to bring you up to speed.