Written byPeter KelleySource
University of Washington
March 1, 2016
Research Highlight
Life or Illusion? Avoiding ‘False Positives’ in the Search for Living Worlds
New research will help astronomers better identify and rule out “false positives” in the ongoing search for life. This image is an illustration of the planet Kepler 62E, about 1,200 light-years away in the constellation Lyra. Image credit: NASA
Is it life, or merely the illusion of life?
Research from the NASA-funded, University of Washington-based Virtual Planetary Laboratory published Feb. 26 in Astrophysical Journal Letters will help astronomers better identify — and thus rule out — ‘false positives’ in the search for life beyond Earth.
Powerful devices such as the James Webb Space Telescope, set for launch in 2018, may help astronomers look for life on a handful of faraway worlds by searching for, among other things, evidence of oxygen — a ‘biosignature’ — in their atmospheres. This is done by transit spectroscopy, or studying the spectral features of light visible through a planet’s atmosphere when it transits or passes in front of its host star.
“We wanted to determine if there was something we could observe that gave away these ‘false positive’ cases among exoplanets,” said lead author Edward Schwieterman, a doctoral student in astronomy. “We call them ‘biosignature impostors’ in the paper.
“The potential discovery of life beyond our solar system is of such a huge magnitude and consequence, we really need to be sure we’ve got it right — that when we interpret the light from these exoplanets we know exactly what we’re looking for, and what could fool us.”