4 articles
Biosignatures look for the chemical exhaust of living things in far-off atmospheres. Technosignatures listen for radio hums and laser pulses from technology. They are the two roads to alien life - and each has its own way of fooling us.
When a planet crosses its star, a sliver of light filters through its atmosphere and certain colors vanish - the fingerprints of its gases. That faint signal is how the search for life beyond Earth actually works, and why a promising result is never proof.
For at least one full 33-day orbit, the VLA and MeerKAT swept the famous exoplanet across radio frequencies sensitive enough to catch a trillion-watt beacon. A SETI team found no artificial signal - though they are careful about what that silence proves.
A new arXiv paper and Keck Institute study argue that the five-spacecraft LIFE mission has cleared its core engineering hurdles - raising the first plausible technical pathway to directly sampling the atmospheres of Earth-like exoplanets for chemical signs of life.
