Geology Flashcards
Geological aspects of Astrobiology
when did the cosmic epoch start?
13.8 Ga
when did the geological epoch start?
4.56 Ga
what is the name given to the process of building and destroying lithospheric crust?
Plate Tectonics
what are the advantages of non-marine waters?
- diverse mineralogy
- salinity, pH and temperature gradients across subsurface brines
what are the advantages of Beaches?
- porous sediments with gradients in light, salinity, pH and temperature
- interface between ocean, land and atmosphere
what are the Astrobiological implications of geochemistry?
- it is important to focus on geological dynamics of a planet rather than the exact origin of life on the planet
- planets that lack environmental diversity may not have the capacity to develop life, regardless of the chemical composition and inventory
- any rocky planet with active geological and hydro-logical cycles can host life
what are the 5 examples of CHONPS in space?
- Meteorites
- Asteroids
- Comets
- Interplanetary Dust Particles
- Pre-solar Grains
when did the Late Heavy Bombardment (LHB) end?
3.85 Ga
what was the chemical composition of earth like before the Great oxidation event?
- comprised mainly of volcanic gases
- h2, h20, co2, n2, so2, h2s –> 80% being N2
what are the names and years of the epochs of earth?
- Hadean (4.56 - 4 Ga)
- Archean (4 - 2.5 Ga)
- Proterozoic (2.5 - 0.5 Ga)
what are the names and years of the epochs of mars?
- Noachian (4.1-3.7 Ga)
- Hesperian (3.7-3 Ga)
- Amzonian (3 Ga - now)
describe the Noachian period
- Sub-glacial lakes on mars
- contains brine-soaked sediments
- thick atmosphere
- surface liquid water
describe the Hesperian period
- flooding caused by volcanism on the planet
- acidic conditions also due to volcanism
- contained hydrothermal vents
- surface radiation
- atmospheric thinning
describe the amazonian period
- the mars we see today
- planet froze and lost its water and volcanism due to loss of magnetic field
Name some of the other water worlds
- Europa
- Ganymede
- Calisto
- Enceladus
What are the benefits of hydrothermal vents and cyrovolcanic plumes?
- allows for interactions that generate important chemical reactions for life
- allows for CHNOPS transportation
What does ISRU stand for?
In situ resource utilisation
- collection, processing, storing and use of materials found on other astronomical bodies
Describe terraforming
-terraforming is the process of changing the natural enviroment of a planet.
-this would be changing things like
temperature, ecology and atmospheric composition
Give three examples of astronomical objects with basalt
- Earth
- The Moon
- Mars
Where are the best places on earth to find meteorites ?
- Deserts
- Antarctic
What are chondrites?
- a type of meteorite which has pockets of coloured minerals
- the colours in them due to the flash heating
Describe the Earth Similarity Index
A scale of 0 to 1 of how similar a planetary mass or natural satellite is to earth
- accounts for physical quantities such as mass, radius, escape velocity but not geological processes
What are the three rock types found on earth?
- Igneous
- sedimentary
- metaphoric (not so important in astrobio as only really found on earth)
