1. Europa
Kaitlyn Young

2. Discovery January 8, 1610 by Galileo Galilei
Sixth closest moon to Jupiter
Smallest of the four Galilean moons, sixth largest moon in Solar System

3. General Information Orbit Size: 671,000 km
Mean Orbit Velocity: 49,476.1 km/h
Orbit Eccentricity:
Density: g/cm3
Surface Gravity: m/s2
Escape velocity: 2026 m/s
Rotational Period: 3.5 Earth Days

4. Surface Water ice with linear fractures Not very cratered
40-90 million years old

5. Surface Clay-like material found – phyllosilicates
Organic material from comet or asteroid
Asteroid (1,100m) or Comet (5,600m) diameter
Galileo Orbiter

6. Surface Strange pits and domes – convecting due to heat below surface
“Chaos terrain” – mysterious reddish brown material

7. Surface
“Chaos terrain” – places where surface has collapsed above lakes within the ice
Conamara Chaos – ice particles, mineral contaminants spread by water vapor

8. Lineaments Four classes by age (Galileo observations) Cracks Ridges
Triple Bands
Ancient Bands

9. LIneaments Record of stresses due to tides
Point in different directions but the same part of ice shell always faces Jupiter
Hypothesis: frozen outer shell rotates faster than moon orbits Jupiter

10. Lineaments 1. Rotation of ice shell (250,000 years)
2. Tilted axis, changing pole orientation
3. Cracks laid out in random directions

11. Surface Galileo Mission Lenticulae
Warm ice moving upward, colder ice sinks downward

12. Magnetic Field Galileo spacecraft
Magnetic-field lines from Jupiter bent around Europa
Implies special magnetic field created inside Europa
Hypothesis: global ocean of salt water creating magnetic field

13. FLybys Pioneer 10 & 11 – 1970s Voyager 1 -1979 Voyager 2 – 1980
Galileo – 1995 (12)
Cassini

14. Voyager missions
Voyager 1 – linear fractures due to tectonic processes
Voyager 2 – fractures lack topological relief
Tidal heating  survival of oceanic organisms

15. core Thin ice model vs thick ice model
Iron core, rocky mantle like Earth

16. Evidence for an Ocean Est 50 km ocean Magnetic field
Few impact craters
Linear surface features fit pattern of fractures if there was an ocean
Tidal heating

17. Plumes? Hubble Space Telescope (2012)
Ultraviolet Imaging Spectrograph (UVIS) Cassini (2014)

18. Life? Tidal heating  energy for oceanic organisms Plumes
Ocean believed to have direct contact with rocky interior (similar to Earth’s sea floor)
Minimum requirements: liquid water, essential chemical elements, source of energy

19. Future Missions Instruments
ICEMAG – Interior Characterization of Europa using Magnetometry
MISE – Mapping Imaging Spectrometer for Europa (probe)
REASON – Radar for Europa Assessment and Sounding: Ocean to Near-surface
Need to withstand 5.40Sv of radiation

20. Future Missions ($80M)
Europa Multiple-Flyby Mission – explore for habitability, select future lander sites – orbit Jupiter
Ice-penetrating radar, short-waved IR spectrometer, topographical imager, ion- & neutral-mass spectrometer
Europa Orbiter – characterize extent of ocean
Radio subsystem, laser altimeter, magnetometer, mapping camera, Langmuir probe
European Space Agency – Jupiter Icy Moon Explorer (JUICE)
Flybys of Europa, but focused on Ganymede

21. Bibliography http://solarsystem.nasa.gov/planets/europa/indepth