An international research team led out of NASA’s Goddard Space
Flight Center have obtained the first direct detection of water
vapor on Jupiter’s moon, Europa. This came in the form of an
infrared signal, captured by an instrument on the Keck Telescope
in Hawaii. Past NASA missions and earthbound telescopes have
found strong evidence suggesting there is an ocean of water
beneath Europa’s icy surface, and plumes seemingly bursting
thru cracks into space. In this recent study, the scientists
observed the entire surface of Europa over seventeen dates in
2016 and 2017. In one instance, there was a short-lived spike in
infrared light – a spectral fingerprint that could only be
due to water vapor. When water escapes from Europa’s subsurface
reservoirs, the resulting vapor is exposed to radiation from the
sun, and the H2O molecules give off a distinctive infrared glow.
This glowing signal – detected by Keck – allowed scientists the
first direct measurement of water vapor on Europa. And here,
scientists measured over two thousand tons of water in the
plume, nearly the volume of an Olympic swimming pool. While
scientists currently have limited ability to detect liquid
water on Europa, this new detection of water in vapor form
is the next best thing in the search for one of the most
essential ingredients for life. This discovery will inform
future observations of Europa, including NASA’s upcoming Europa
Clipper mission, which will study the Jovian moon at close
range. These efforts should further unlock the secrets of
Europa and its potential for life beyond Earth.