Life Detected on Earth (And It's Good News)

How can we detect life on exoplanets? A promising space mission is in the works.

The LIFE mission, a collaboration between ETH Zurich and the University of Zurich, aims to unravel the mystery of life's existence on other planets. At the heart of this initiative, five satellites will work together to form a large space telescope capable of analyzing the infrared thermal emissions of exoplanets. This groundbreaking technology could revolutionize our understanding of distant worlds and their potential habitability.


In a recent study published in The Astrophysical Journal, researchers put the capabilities of the LIFE mission to the test by using our own planet as a test object. They utilized actual infrared thermal emission spectra, collected by NASA's Earth observation satellite Aqua, to simulate what the LIFE telescope could observe when scanning Earth-like exoplanets. This unique approach has validated the envisioned measurement process for the mission.

The challenge was to determine if, by observing Earth as a mere distant speck, the space telescope would be able to recognize signs of life. The results were promising: regardless of the observation geometry and seasonal fluctuations, the LIFE telescope could identify significant concentrations of gases such as CO2, water, ozone, and methane. These gases, particularly ozone and methane, are crucial as they are produced by the Earth's biosphere.

This detection capability proves to be independent of the observation position, a significant advancement given that the exact geometry for future observations of Earth-like exoplanets remains uncertain. Although atmospheric seasonality proves difficult to observe, the study confirms that next-generation space missions will have the ability to assess the habitability, and possibly the habitation, of nearby temperate Earth-like exoplanets.