Exploring the Icy Ocean World Europa
Krista M. Soderlund
19 August 2020 Outline
1) Introduction to Icy Ocean Worlds • Follow the water to subsurface oceans in the outer solar system 2) Europa - potential abode for life • What do we know (and don’t know) • Implications for habitability 3) Europa Clipper • Flagship-class mission to explore Europa’s habitability 4) Future Exploration Outline
1) Introduction to Icy Ocean Worlds • Follow the water to subsurface oceans in the outer solar system 2) Europa - potential abode for life • What do we know (and don’t know) • Implications for habitability 3) Europa Clipper • Flagship-class mission to explore Europa’s habitability 4) Future Exploration What makes a world habitable?
• Traditionally, a world is considered habitable if it can support liquid water on its surface.
Philosophy of "follow the water" guides Mars habitability investigations What makes a world habitable?
• Traditionally, a world is considered habitable if it can support liquid water on its surface.
Philosophy of "follow the water" guides Mars habitability investigations
In the outer solar system, liquid water exists in subsurface oceans hidden by an outer shell of ice
Credit: NASA Icy Ocean Worlds
Credit: NASA/JPL/K. P. Hand Icy Ocean Worlds
Ceres
Credit: NASA/JPL/K. P. Hand Icy Ocean Worlds
Ceres
Credit: NASA/JPL/K. P. Hand Icy Ocean Worlds
Mimas
Ceres
Credit: NASA/JPL/K. P. Hand Icy Ocean Worlds
Mimas
Ceres
Credit: NASA/JPL/K. P. Hand Icy Ocean Worlds
Mimas
Ceres
Credit: NASA/JPL/K. P. Hand Outline
1) Introduction to Icy Ocean Worlds • Follow the water to subsurface oceans in the outer solar system 2) Europa - potential abode for life • What do we know (and don’t know) • Implications for habitability 3) Europa Clipper • Flagship-class mission to explore Europa’s habitability 4) Future Exploration History of Exploration
• Discovered by Galileo in 1610
G I/E C
G I E
C G/E
G C
E G I
I - Io E - Europa GIC E G - Ganymede C - Callisto History of Exploration
• Discovered by Galileo in 1610
G I/E C
G I E
C G/E
G C
E G I
I - Io E - Europa GIC E G - Ganymede C - Callisto
Credit: Saint John Astronomy Club Pioneer 10 flyby, 1973 Pioneer 11 flyby, 1974 History of Exploration
• Discovered by Galileo in 1610 • Pioneer 10 flyby in 1973, Pioneer 11 flyby in 1974
Credit: NASA Pioneer 10 flyby, 1973 Pioneer 11 flyby, 1974 Voyager 1 flyby, 1979 Voyager 2 flyby, 1979 History of Exploration
• Discovered by Galileo in 1610 • Pioneer 10 flyby in 1973, Pioneer 11 flyby in 1974 • Voyager 1 flyby in 1979, Voyager 2 flyby in 1979
Credit: NASA Pioneer 10 flyby, 1973 Pioneer 11 flyby, 1974 Voyager 1 flyby, 1979 Voyager 2 flyby, 1979 Galileo, 1995-2003 History of Exploration
• Discovered by Galileo in 1610 • Pioneer 10 flyby in 1973, Pioneer 11 flyby in 1974 • Voyager 1 flyby in 1979, Voyager 2 flyby in 1979 • Galileo spacecraft toured the Jovian system for 8 yrs
Credit: NASA/NOAO/DLR Pioneer 10 flyby, 1973 Pioneer 11 flyby, 1974 Voyager 1 flyby, 1979 Voyager 2 flyby, 1979 Galileo, 1995-2003 History of Exploration New Horizons flyby, 2007
• Discovered by Galileo in 1610 • Pioneer 10 flyby in 1973, Pioneer 11 flyby in 1974 • Voyager 1 flyby in 1979, Voyager 2 flyby in 1979 • Galileo spacecraft toured the Jovian system for 8 yrs • New Horizons flyby in 2007
Credit: NASA Pioneer 10 flyby, 1973 Pioneer 11 flyby, 1974 Voyager 1 flyby, 1979 Voyager 2 flyby, 1979 Galileo, 1995-2003 History of Exploration New Horizons flyby, 2007 Juno, 2016- • Discovered by Galileo in 1610 • Pioneer 10 flyby in 1973, Pioneer 11 flyby in 1974 • Voyager 1 flyby in 1979, Voyager 2 flyby in 1979 • Galileo spacecraft toured the Jovian system for 8 yrs • New Horizons flyby in 2007 • Juno in orbit around Jupiter
Credit: NASA Europa
• Fundamental propertiesEUROPA
Europa Earth Unit
Distance from Jupiter 0.67 106 km
Rotation period 3.55 1 days
Radius 1561 6371 km
Density 3013 5515 kg.m-3 The outer ice shell hides a global liquid water ocean Gravity 1.31 9.80 m.s-2 that contains more water than the Earth’s oceans Facts
Global subsurface ocean Credit: NASA Englacial lakes Potential plume activity Unique and varied geology Habitability Candidate Europa
• Evidence for a global subsurface ocean of salty water
Bands and Ridges
Geology: Young/smooth surface, Crater relaxation, Endogenic salts, Englacial water? Chaos Terrain Impact Craters
Credit: NASA/JPL/DLR Europa
• Evidence for a global subsurface ocean of salty water
Geology: Young/smooth surface, Gravity: Crater relaxation, Differentiated, Mostly rock, Endogenic salts, Outer water layer(s?) Englacial water?
Credit: NASA Europa
• Evidence for a global subsurface ocean of salty water
Geology: Young/smooth surface, Gravity: Crater relaxation, Differentiated, Mostly rock, Endogenic salts, Outer water layer(s?) Englacial water? Magnetometer: Induced magnetic field near the surface
Credit: NASA Europa
• Evidence for a global subsurface ocean of salty water
Geology: Young/smooth surface, Gravity: Crater relaxation, Differentiated, Mostly rock, Plumes: Endogenic salts, Outer water layer(s?) Liquid water Englacial water? beneath the surface Magnetometer: Induced magnetic field near the surface
Credit: NASA Europa
• Tidal heating maintains the ocean for billions of years
Credit: NASA Outstanding Questions
• How are Europa’s unique geologic features formed? Do pockets of liquid water exist within the ice shell?
Credit: NASA Outstanding Questions
• How thick are the ice shell and ocean?
Credit: NASA/JPL/Michael Carroll Outstanding Questions
• What are the non-ice components of the ice shell? What is the ocean composition and its salinity?
More NaCl
Less NaCl
Credit: NASA/Trumbo et al. 2019 Outstanding Questions
• Is the rocky mantle hot?
Credit: ROV KIEL 6000/GEOMAR/GNS Outstanding Questions
• How are heat and material exchanged between the surface, ice shell, ocean and seafloor?
Ice Shell Spreading Center
Ocean Convection
Credit: NASA/JPL/Howell & Pappalardo 2018/Soderlund et al. 2013 Outstanding Questions
• How active is Europa today?
Voyager 2 (1979) Galileo (1998)
Lack of change at ~2 km/pixel scale over 20 yrs <1 km2/yr resurfacing rate >30 Myr age
Credit: NASA/Roth et al. 2014 Is Europa habitable? Energy Water Chemical energy to Solvent supporting sustain metabolic biochemical reactions activity
Water
Time
Chemistry Energy
Chemistry Building blocks for life to grow and reproduce (CHNOPS) Is Europa habitable?
• Conditions along the ice-ocean interface are similar to those below Antarctic ice shelves
Credit: NASA/Planet Observer/Universal Images Group/N. Wolfenbarger/C. Yakiwchuck, E. van Wijk, R. Coleman Is Europa habitable?
• Conditions along the ice-ocean interface are similar to those below Antarctic ice shelves
Credit: Frank Rack, Andrill Science Management Office, University of Nebraska -Lincoln
10 cm
Edwardsiella andrillae anemones living in the base of the Ross Ice Shelf
Credit: NASA/Planet Observer/Universal Images Group/N. Wolfenbarger/C. Yakiwchuck, E. van Wijk, R. Coleman Is Europa habitable?
• Pressure at the seafloor would be 130-260 MPa, corresponding to 13-26 km depth of a theoretical Earth's ocean
Credit: NASA/K.P. Hand/NOAA Is Europa habitable?
• Pressure at the seafloor would be 130-260 MPa, corresponding to 13-26 km depth of a theoretical Earth's ocean
Credit: NASA/K.P. Hand/NOAA Is Europa habitable?
Credit: K. P. Hand/JPL/NASA Outline
1) Introduction to Icy Ocean Worlds • Follow the water to subsurface oceans in the outer solar system 2) Europa - potential abode for life • What do we know (and don’t know) • Implications for habitability 3) Europa Clipper • Flagship-class mission to explore Europa’s habitability 4) Future Exploration NASA’s Europa Clipper Mission
• Goal: Explore Europa to investigate its habitability - Ice Shell & Ocean: Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange - Composition: Understand the habitability of Europa’s ocean through composition and chemistry - Geology: Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities - Current Activity: Search for and characterize any current activity, notably plumes and thermal anomalies Europa Clipper Science
MASPEX ECM Magnetometer Mass Spectrometer sniffing atmospheric SUDA sensing ocean PIMS composition Dust Analyzer properties Faraday Cups surface & plume plasma environment composition
Europa-UVS E-THEMIS REASON UV Spectrograph Thermal Imager Ice-Pentrating Radar surface & plume/ searching for hot spots plumbing the ice shell atmosphere composition
EIS Narrow-angle Camera + MISE Wide-angle Camera IR Spectrometer mapping alien landscape in surface chemical 3D & color fingerprints
In Situ Remote Sensing
Gravity internal structure Europa Clipper Synergistic Science
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging Infrared
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging Infrared Thermal
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging Infrared Thermal Radar
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging Infrared Thermal Radar Ultraviolet
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Europa Clipper Synergistic Science Gravity Magnetometry + Plasma Imaging Infrared Thermal Radar Ultraviolet Gas + Dust Mass Spectroscopy
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Multiple-Flyby Concept of Operations
• Multiple satellite gravity assists enables “globally-distributed regional coverage” of Europa from orbit around Jupiter • Minimizes time in high radiation environment • Current mission design has ~40 low altitude flybys over ~4 years • Simple repetitive operations
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Spacecraft
Mag Boom ~16.5 ft (5 m) High Gain Antenna ~10 ft (3 m)
22 N Thrusters (x16)
Solar Array Panels ~15 ft (4.5 m) per wing ~100 m² area Forward-Pointed Instruments
Downward-Pointed Instruments
Radar VHF Antenna (x4)
Radar HF Antenna (x2) ~52.5 ft (16 m)
Copyright 2018 California Institute of Technology. Government sponsorship acknowledged Outline
1) Introduction to Icy Ocean Worlds • Follow the water to subsurface oceans in the outer solar system 2) Europa - potential abode for life • What do we know and how do we know it? • Implications for habitability 3) Europa Clipper • Flagship-class mission to explore Europa’s habitability 4) Future Exploration Europa Lander Mission Concept
1. Search for evidence of life on Europa 2. Assess the habitability of Europa via in situ
GOAL 1 techniques Biosignatures 3. Characterize the surface and subsurface to enable future robotic exploration
GOAL 3 GOAL 2 Surface Habitability Properties and Dynamics
Credit: NASA Drills and Submersibles
Ice Mole drill DEPTHX underwater vehicle
Credit: FH Aachen
Credit: Stone Aerospace SLUSH drill Credit: B. Schmidt/Icefin/RISEUP
Credit: Honeybee Robotics Icefin underwater vehicle On to Europa!
Krista M. Soderlund