Searching for Life on Exoplanets ^{CEFR B1}

The first planet found orbiting a Sun-like star outside our solar system was reported in 1995. That discovery opened a new field of research about worlds beyond Earth and later contributed to part of the 2019 Nobel Prize in Physics. Since then researchers have discovered more than 4,000 exoplanets, and some appear Earth-like and might be able to harbor life.

Over the last decade astronomers focused on finding traces of simple life, which they call biosignatures. A biosignature can be a chemical or a pattern that indicates biological activity. Finding reliable biosignatures across space remains difficult, so it is a major research goal.

Another question asks whether technological civilizations could leave easier-to-detect signs. Scientists use the word technosignatures for traces of technology or large-scale engineering that might be visible from Earth. A NASA grant now enables astrophysicist Adam Frank to define what such technological traces might look like and how they could be seen at interstellar distances. Part of his work compares evidence from simple life and from technological civilizations.

Researchers continue to develop methods to detect both biosignatures and technosignatures, by defining which signals to look for and then searching the growing catalog of exoplanets. It is not yet clear which approach will succeed first, or whether either will provide definitive proof of life beyond Earth. Adam Frank discusses these questions in a video; the University of Rochester provided the source material and the post appeared on Futurity.