Icy Moons**** (Week 8)

Question 1

what makes water a unique solvent

Answer 1

• abundant- most abundant in the universe
• stable over a wide range of temperatures- 100 on earths surface by high pressure and salts can cause increase
• polar so can dissolve many solutes like CHNOPS

Question 2

name 3 icy moons

Answer 2

• titan
• europa
• enceladud

Question 3

what is tidal heating (jovian system)

Answer 3

• orbits are in resonance
• moons squashed and stretched, generating heat

Question 4

why does the size of icy moons matter

Answer 4

-generate high pressure ice that ‘seals’ liquid ocean between two layers of ice

Question 5

rock/ water interactions like in open oceans

Answer 5

• delivers essential chemical compounds to oceans
• on earth deep hydrothermal vents are important for the origins of life
• now they have chemoautotrophs

Question 6

name the sealed ocean worlds in the solar system

Answer 6

ganymede and collisto
- both have larger diameters and open ocean
- tectonics on ganymede and heavily cratered on callisto

Question 7

what are the open ocean worlds in the solar system

Answer 7

• enceladus and europa
• smaller diameters
  ice shells between 5- 35 km thick

Question 8

what unique feature does Enceladus present

Answer 8

• tiger stripes which are a source of plumes
• these are up to 100k warmer than the surrounding surface

Question 9

cryovolcanic plumes were investigated by what mission

Answer 9

• NASA/ESA cassini- huygens probe
• at saturn 2004-2017

Question 10

what does enceladus contain

Answer 10

• water ice
• salts
• gases
• silica
  -organics
  soda ocean has ph between 9-12

Question 11

what makes enceladus interesting for astrobiology

Answer 11

• hydrothermal activity in a liquid water ocean
• water-rock interactions
• H2 in plumes which means a source of energy which can be used by methanogens
• High PH ocean which potential alkaliphilic microorganisms

Question 12

what mission explored europa

Answer 12

• galileo NASA mission between 1995- 2003

Question 13

EXPLAIN EUROPAS CRYOVOLCANISM

Answer 13

• europas ‘lineae’ - fractures/extensional features associated with ‘non- icy’ material
• chaos terrain formed by subsurface meltwaters
• active cryovolcanic centres??

Question 14

• plumes on europa- evidence and what they do

Answer 14

• earth- based telescopes and hubble have observed evidence
• UV spectroscopy
• transient
• bringing ocean material to the surface