Europa Clipper has a powerful suite of nine science instruments that will work in sync while collecting data to accomplish the mission’s science objectives. During each flyby, the full array of instruments will gather measurements and images that will be layered together to paint the full picture of Europa.
Through thoughtful collaboration, the mission’s scientists will attempt to determine whether there are places below the surface of Europa that could support life. The spacecraft does not have life-seeking instruments. Instead, we must first:
- Determine the thickness of Europa’s icy shell, and understand how Europa’s ocean interacts with the surface
- Investigate the composition of Europa’s ocean to determine if it has the ingredients to permit and sustain life
- Study how Europa’s surface features formed and locate any signs of recent activity, such as sliding crust plates or plumes that are venting water into space
Imagers
Cameras
Europa Clipper’s visible-light cameras (extending slightly into near-infrared and ultraviolet wavelengths) will map Europa at far better resolution than previous missions. The spacecraft’s two infrared cameras will map the moon’s surface composition, temperature, and roughness. Together, the cameras and other instruments will reveal much about Europa’s chemistry and geologic activity.
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A wide-angle camera and a narrow-angle camera, each with an eight-megapixel sensor, will produce high-resolution color and stereoscopic images of Europa. They will study geologic activity, measure surface elevations, and provide context for other instruments.
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The thermal imager uses infrared light to distinguish warmer regions on Europa where warm liquid water may be near the surface or might have erupted onto the surface. It will also measure surface texture to understand the small-scale properties of the surface.
Spectrometry
Different atoms and molecules emit, absorb, and reflect various wavelengths of light in telltale ways. As such, light carries information about materials it has interacted with. Europa Clipper’s spectrometer and spectrograph will dissect incoming infrared and ultraviolet light to decode that information and reveal the composition of Europa’s surface, and of particles in space near Europa.
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By collecting ultraviolet light with a telescope, and creating images, the mission’s ultraviolet spectrograph will help determine the composition of Europa’s atmospheric gases and surface materials. It will also search near Europa for signs of plume activity.
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The mission’s infrared spectrometer will map the distribution of ices, salts, organics, and the warmest hotspots on Europa. The maps will help scientists understand the moon’s geologic history and determine if Europa’s suspected ocean is suitable for life.
Plasma and Magnetic Field
Jupiter’s magnetic field, the largest in the solar system, traps the charged particle gas – plasma – that fills the space surrounding Europa (and the rest of the Jupiter system). As Europa moves in its orbit, the magnetic field varies. Time-variations of the magnetic field induce Europa to produce its own magnetic field that, in turn, will provide clues to the structure of the moon’s interior.
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The magnetometer investigation aims to confirm that Europa’s ocean exists, measure its depth and salinity, and measure the moon’s ice shell thickness. It will also study Europa’s ionized atmosphere and how it interacts with Jupiter’s ionized atmosphere.
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Europa’s ionosphere, and plasma trapped in Jupiter’s magnetic field, distort magnetic fields near Europa. PIMS Faraday cups will distinguish those distortions from Europa’s induced magnetic field, which carries information about Europa’s ocean.
Radar & Gravity
Europa’s physical properties affect radio signals, which will help reveal the moon’s interior. A gravity experiment will analyze frequency shifts in the spacecraft’s signals to Earth (the same signals used in communication and navigation) to study Europa’s internal structure. A radar instrument will transmit radio into Europa’s icy shell and analyze the bounced signals to “see” internal features.
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Europa and its gravity field flex as the moon’s non-circular orbit carries it closer, then farther, from Jupiter. Measuring Europa’s gravity at various points in the moon’s orbit will show how Europa flexes and help reveal its internal structure.
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Ice-penetrating radar will probe Europa’s icy shell for the moon’s suspected ocean and study the ice’s structure and thickness. It will also study the moon’s surface elevations, composition, and roughness, and search the moon’s atmosphere for plumes.
Chemical Analysis
Radar and cameras “look” at things from afar, while other science instruments such as magnetometers sense the environment immediately around the spacecraft. Still others collect gas and dust in space to identify their chemical makeup. Europa Clipper’s complementary dust spectrometer and neutral gas mass spectrometer perform such collections; they are the mission’s “hands-on” experiments.
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The mass spectrometer will analyze gases in Europa’s faint atmosphere and possible plumes. It will study the chemistry of the moon’s suspected subsurface ocean, how ocean and surface exchange material, and how radiation alters compounds on the moon’s surface.
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Tiny meteorites eject bits of Europa’s surface into space, and a subsurface ocean or reservoirs might vent material into space as plumes. The dust analyzer will identify that material’s chemistry and area of origin, and offer clues to Europa’s ocean salinity.
Conclusion
Whatever Europa Clipper reveals could change our understanding of the solar system, and other planetary systems, forever. "This is a giant step in our search for oases that could support life in our own celestial backyard," said Curt Niebur, Europa program scientist at NASA Headquarters in Washington. "We're confident that this versatile set of science instruments would produce exciting discoveries on a much-anticipated mission."
