exam 3 Flashcards
Where is there liquid water in our solar system? How do these water quantities compare with that of Earth?
Europa: its roughly 6% water
More water than earth
Ganymede: 6% water
Has an ice crust and ice mantel
More water than earth
Calisto: twice the amount of water than earth
Enceladus: 14% water
But the water is a lot less than that of earth because the moon is so small
Titan: 11% ocean
Pluto: A little less water than earth does
Compared to Earth, how much liquid water is there on Mars? Venus? Why?
- Mars has frozen water on the poles
- Thin atmosphere and weak magnetic field
- So no interior heating to keep liquid water
- No water on Venus because
- 5832 hours is one day because it’s closer to the sun
- What does a slower rotation cause? A weaker magnetic field
o Because the magnetic field (protector) went away
For magnetic field you need BOTH fast rotation and liquid metal core
o Solar wind bombards atmosphere and breaks up water vapor
basic goals and capabilities of curiosity
Curiosity: rover’s goals include an investigation of the Martian climate and geology
- Looked for environmental conditions favorable for microbial life, including investigation of the role of water
basic goals and capabilities of insight
Insight: To understand how rocky planets formed and evolved, InSight will study the interior structure and processes of Mars
- InSight will figure out just how tectonically active Mars is today, and how often meteorites impact it
- Designed to study mars interior
- Measuring seismic activity
- Designed to drill 5 meters deep
- FOUND that mars has MARSQUAKES
- Unusual because its small and geologically inactive
What causes a planet/moon to remain hot inside?
1) Stellar radiation (sunlight)
2) Leftover heat from formation
3) Tidal heating
4) Collisional heating
5) Radioactive decay
What is a tardigrade/ water bear
Water bear is the most extreme animal on earth (microbial)
- can survive Minus 300 degrees F
- Dies and comes back to life
- Tolerant (can survive but can’t grow) vs Pilic (can grow and reproduce in that harsh environments)
- Water bear is tolerant
Understand the Drake Equation. What is it trying to accomplish? What are its limitations?
Accomplish: tries to understand the number of civilizations in the Milky Way Galaxy whos electromagnetic emissions are detectable
Limitations: gross oversimplification of what enables intelligent life to develop
Understand tidal heating. How does it work? What is necessary for it to happen?
- Tidal heating is caused by a cycle of flexing where thermal energy is produced. It creates geologic activity and is a source of internal heating for moons/planets.
- Only a change in stretching chanes tidal heating
- When the moon is closer it stretches
- When the moon is farther away it stops stretching
- IO has an eccentric orbit and has major tidal heating
- Enceledus’s source of heat is tidal heating
Jupiter’s moons in order of size
Size (largest to smallest): Ganymede, Callisto, Io, Europa
Jupiter’s moons in order of distance
(closest to farthest): Io, Europa, Ganymede, and Callisto
- Gravity depends on mass and distance
- Moons energy comes from tidal heating
- Io is experiencing the most gravity and has more heat and tidal heating
- Has so many volcanoes because of tidal heating
- Europa has nice comfortable oceans because it is second closest
Pros and cons of IO
Pro: Io is experiencing the most gravity and has more heat and tidal heating
Has so many volcanoes because of tidal heating
Con: Very very cold temps with hot volcanos
- Not a stable warm environment
- Has no water on surface because it has the most volcanoes out of any planet and that heat evaporates water
Pros and cons of europa
Pros: Liquid water significantly larger than earth’s oceans
o Thermal vents provide energy and warmth
o Oceans are believed to possess all chemical ingredients needed for life
Europa has nice comfortable oceans because it is second closest
Cons: While Europa has energy sources for life, this energy is small compared to the overall energy (solar and thermal vents) available for life on earth
o Some scientists believe that specialized environments found on earth are needed to generate the best chemical ingredients for life
Pros and cons of Ganymede
Pro: Has large liquid water ocean sandwiched between ice
Con:
Pros and cons of Callisto
Pro:
Con: Furthest from Jupiter, oceans are small
- You can tell its furthest because its coldest inside
- Thus, has the least amount of tidal heating/ not as much gravity
Pros and cons of Titan
Pro: The only known moon with a real atmosphere
- The atmosphere is even thicker than earths
- Nonstop drizzle of ethane and/or methane rain
- Has storms, weathering, and liquid on surface
o Has surface lakes of methane and ethane
Good but not as good as water
o Liquid hydrocarbons on the surface
o Likely cryovolcanoes
Source of energy, movement, and chemical ingredient/reactions
o People are interested in methane-based life largely because of titan
Cons: Ethane and methane could not likely replace water
Pros and cons of Enceladus
Pro: Diverse terrain ranging from old cratered to young tectonically deformed
- Has water rich geysers. These cryovolcanoes are feeding Saturn’s outer ring
- Geysers imply that there is a subsurface liquid water
- And a heat source
- Ocean is touching the moon core and contains salts and organic hydrocarbons
- Good place for life
- Has thermal vents
- Oceans source of energy: tidal heating
Cons:
What is Lake Vostoc? How does it help us understand possibilities for life in the universe?
- Lake Vostoc is a frozen lake in Antarctica
- It’s the largest of Antarctica’s subglacial lakes
- It has a heat source down below
- The lake is touching rock (creates saltiness)
- This could be what the environment of Europa looks like
- Most studies show microbial life forms to be far more diverse than originally expected
- Has been sealed off from all sunlight for 15 million years
- We didn’t want to contaminate the lake, but Russia studied it first
What is a rogue planet? How is it relevant to life in the Universe?
- Its a planet that was ejected out of its solar system because the solar system is unstable and light planets like rocky ones can easily be ejected out of solar system
- You could have a large planet floating by itself (no star) with moons around it with life on the planet
- If the planet has internal heating or if the planet was very large, it would still be able to have liquid water ocean
- These planets could very easily habitable
Compared to other moon or planet surfaces, what is different about Titan’s surface, with respect to the potential for life?
- It’s the only known moon with an atmosphere
- Its thick
- Nonstop drizzle of ethane and/or methane
- Largest moon of any mass
- Cold temps keep atmosphere close
- Has cryovolcanoes and liquid lakes of methane and ethane
- Liquid hydrocarbons on surface
- People are interesting in methane-based life
- Subsurface it has so much liquid water
Compare and contrast Water, Methane, Ethane, Ammonia, including knowing their chemical formulas.
- Water and ammonia are similar molecules
- Water is polar: has one negative charge and two positive
- We can think of life based on ammonia
- Ammonia: freezing point is lower
- Ethane and methane could not likely replace liquid water
What is the Turing test? What does it seek to understand? How does a machine pass the Turing test?
- Alan Turing came up with a test to see if a person could decipher if a person was talking to a computer or person
- It seeks to determine whether or not a computer is capable of thinking like a human being
- A machine passes the turing test when it convinces the humans on the other end of the conversation that they are talking to a human
What makes Enceladus an intriguing place to visit?
- Cassini mission found that the surface was young (replenishing itself)
- Presence of water volcanism or
- Liquid is formed by high temps
- Found that the ocean has molecules that can be the precursors for life
- Pre biotic conditions are especially intriguing to visit
- The dust particles can even reveal its innermost secrets
How is Saturn’s outermost ring formed?
- By enceladus
- Has water rich geysers. These “cryovolcanoes” are feeding Saturn’s outer ring.
What are the different types of subsurface oceans?
1) An ocean that is touching the core or mantel— salt and organic molecules in the rock get dissolved into the water
2) An ocean that is sandwiched between two water-ice layers— ocean water contains mostly pure water
Implication of ocean that is touching the core or mantel
- Enceladus’s ocean is touching the moon core and contains salts and organic molecules
- These molecules are typically useful for life
Implication an ocean that is sandwiched between two water-ice layers
One of ganymedes several ocean layers is sandwiched between two layers of ice
If you were sending a mission to enceladus and took a measurement and found 0 salt, what would this tell you.
Would tell you that the ocean wasn’t touching the core/ mantel
Pluto should be:
- Scientists expected a dead terrible environment for life
- Frozen
- It should not has leftover heat from formation because its too small
- It should not have tidal heating because its not near anything
- There is no energy for life
- New horizons proved this wrong
Pluto is:
- Geologically active
- With very faint atmosphere
- Which is weird because it is so small
- Has liquid water below its surface
- Pluto had a large collision that left internal heating
- Caused pluto’s moons
- NO TIDAL HEATING (because it’s too far)
- Ice flows from mountains and valleys
