Artist's concept of the surface of Europa. Source: NASA/JPL-Caltech
With NASA issuing an Announcement of Opportunity (AO) for instruments and equipment to be carried on a mission to Europa, the possibility of discovering extraterrestrial life is getting closer than ever. Around 20 proposals will be chosen in 2015 and will recieve funding for development. Successful proposals may be carried by an orbiting spacecraft, such as the conceptual Europa Clipper, which would perform a series of flybys of Jupiter's famous moon.
Ideas for proposals include:
- Radar capable of penetrating the surface ice and assessing its thickness,
- Infrared spectrometers for ascertaining the makeup of Europa's surface,
- Topographic cameras capable of high-resolution imaging of geographical features,
- Ion and neutral mass spectrometers for analyzing Europa's atmosphere.
Concept art for the proposed Europa Clipper. Source: NASA/JPL-Caltech
While other efforts concentrate on finding exoplanets suitable for life, a mission to Europa will assess our own solar system as a host for multiple life sources. In addition to the new AO, NASA previously released a Request for Information (RFI) to the science and engineering community, with much the same requirements as listed in the AO.
There was a wider scope to the RFI, as it also included proposals for the spacecraft itself, and stated that the moon's magnetosphere and interaction with the immediate space environment would also be studied, with the caveat that intense radiation levels must be factored in to proposed designs.
In a 2013 paper led by Kevin Hand at NASA's Jet Propulsion Laboratory, it was shown that hydrogen peroxide is abundant on Europa. Given that there is believed to be an ocean under the frozen surface of the moon, the hydrogen peroxide may mix with the water, which would yield oxygen. This could be a source of energy for any life, such as chemosynthetic microorganisms, that may exist there.
Since it is looking increasingly likely that life on Earth began at hydrothermal vents at the bottom of oceans, hitting targets such as Europa would be the quickest way to discover whether life may indeed thrive in the universe. Given that NASA is proposing to invest a significant amount of money and effort in a mission to Europa (rather than another target, such as Enceladus) suggests that there is a extremely strong case for life existing there.
