NASA’s Galileo mission teased the possibility of a vast ocean beneath Europa’s surface. If this strong evidence becomes fact, scientists estimate the moon could have more than twice as much water as Earth. And where there is water, there could be life.
“Europa has tantalized us with its enigmatic icy surface and evidence of a vast ocean, following the amazing data from 11 flybys of the Galileo spacecraft over a decade ago and recent Hubble observations suggesting plumes of water shooting out from the moon,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington.
NASA’s 2016 budget includes a request for $30 million to plan a mission to Europa. Any mission to the moon would be extremely complex, but here are the basics. A solar-powered spacecraft will enter a long orbit around Jupiter. Once there, the spacecraft will conduct 45 flybys of Europa at altitudes ranging from 1,700 miles to just 16 miles above the moon’s surface.
It’s features like this that have scientists theorizing Europa has a warm interior (liquid ocean). Credit: NASA
Today, NASA announced the selection of the mission’s science instruments.
Among the nine instruments, are cameras and spectrometers to capture high-resolution images of Europa’s surface. An ice-penetrating radar will help determine how thick the moon’s icy surface is and search for subsurface lakes.
A magnetometer will measure the strength and direction of Europa’s magnetic field. These measurements will also help scientists figure out the depth and salinity of its ocean.
“We’re excited about the potential of this new mission and these instruments to unravel the mysteries of Europa in our quest to find evidence of life beyond Earth,” said Grunsfeld.
Curt Niebur, a Europa program scientist, is “confident” these instruments will help unveil some of Europa’s secrets.
NASA released additional details about each of the nine science instruments.
Plasma Instrument for Magnetic Sounding (PIMS) — principal investigator Dr. Joseph Westlake of Johns Hopkins Applied Physics Laboratory (APL), Laurel, Maryland. This instrument works in conjunction with a magnetometer and is key to determining Europa’s ice shell thickness, ocean depth, and salinity by correcting the magnetic induction signal for plasma currents around Europa.
Interior Characterization of Europa using Magnetometry (ICEMAG) — principal investigator Dr. Carol Raymond of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California. This magnetometer will measure the magnetic field near Europa and – in conjunction with the PIMS instrument – infer the location, thickness and salinity of Europa’s subsurface ocean using multi-frequency electromagnetic sounding.
Mapping Imaging Spectrometer for Europa (MISE) — principal investigator Dr. Diana Blaney of JPL. This instrument will probe the composition of Europa, identifying and mapping the distributions of organics, salts, acid hydrates, water ice phases, and other materials to determine the habitability of Europa’s ocean.
Europa Imaging System (EIS) — principal investigator Dr. Elizabeth Turtle of APL. The wide and narrow angle cameras on this instrument will map most of Europa at 50 meter (164 foot) resolution, and will provide images of areas of Europa’s surface at up to 100 times higher resolution.
Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) — principal investigator Dr. Donald Blankenship of the University of Texas, Austin. This dual-frequency ice penetrating radar instrument is designed to characterize and sound Europa’s icy crust from the near-surface to the ocean, revealing the hidden structure of Europa’s ice shell and potential water within.
Europa Thermal Emission Imaging System (E-THEMIS) — principal investigator Dr. Philip Christensen of Arizona State University, Tempe. This “heat detector” will provide high spatial resolution, multi-spectral thermal imaging of Europa to help detect active sites, such as potential vents erupting plumes of water into space.
MAss SPectrometer for Planetary EXploration/Europa (MASPEX) — principal investigator Dr. Jack (Hunter) Waite of the Southwest Research Institute (SwRI), San Antonio. This instrument will determine the composition of the surface and subsurface ocean by measuring Europa’s extremely tenuous atmosphere and any surface material ejected into space.
Ultraviolet Spectrograph/Europa (UVS) — principal investigator Dr. Kurt Retherford of SwRI. This instrument will adopt the same technique used by the Hubble Space Telescope to detect the likely presence of water plumes erupting from Europa’s surface. UVS will be able to detect small plumes and will provide valuable data about the composition and dynamics of the moon’s rarefied atmosphere.
SUrface Dust Mass Analyzer (SUDA) — principal investigator Dr. Sascha Kempf of the University of Colorado, Boulder. This instrument will measure the composition of small, solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys.
Europa isn’t the only Jupiter moon that scientists believe harbors an underground ocean. There is evidence Ganymede has one as well.