Are the properties of earths atmosphere the same wherever you are?
No, the Properties of atmosphere depend on height you are at becasue different energies will be absorbed at different heights
Electromagnetic field
Molten Metallic core is electrically conducting, and the earth spinning on its axis activated convective currents in the core cause a magnetic field.
Ozone layer
created by UV breaking apart oxygen molecules
Atmosphere effects
Create pressure (determines presence of liquid water on surface), absorb/scatter light, create weather, protects from solar wind, warm through greenhouse effect.
Lithosphere
Ridgid part of interior, that is part of crust and mantle
Dissociation
Distruction of a molecule (UV/xray)
Impact cratering
Something smashes into the surface (asteroid/comet)
Planetary temperature
depends on energy in/energy out
Conduction
Energy can transfer through material
Stratosphere
UV absrobed due to ozone layer
Moon interior
Small core, large Lithosphere
Why is the earths core hot?
After planet accretion and differentiation, it Lost potential energy = gain kinetic energy (heat)
Mercury interior
Almost all metalic core
Why are sunsets red
Red light scatters less
Weather
Day by day variations
Affect of distance from sun
Too close to sun:
- less erosion (as no wind, ice snow rain)
- to hot for atmosphere
Why is the core denser than the crust?
differentiation, i.e. gravity pulls high density stuff to core, light material rises to surface
Why are mercury and the moon geologically dead?
They had a large surface area to volume ratio, so they cooled more quickly
Lunar maria
Highlands =higher, cratered regions
Maria = lower, smoother less cratered regions (formed latter on)
Surface age based on crattering
Highly cratered surface = surface formed early
Minimal craters = surface formed latter on
Mars interior
large Lithosphere
Convection
Bulk motion
Why is the sky blue?
Atmosphere scatters blue light from sun
What is an atmosphere
a layer of gas that surrounds a plannet
Climate
Long term average
magnetosphere
Interaction between atmosphere and solar wind, which Prevents its charged particles crashing into earth
Earth atmosphere
10km thick, consisting of mainly nitrogen and oxygen
erosion
Surface changes by wind, water, ice
Interior of terrestrial planet
Metal Core, mantle, crust (in order of decreasing density)
Mercury cliff casues
Shrinking of core and mantle caused buckling and resulted in cliff formation
Why did earth retain most of its outgassed water?
Cool enough (distance from sun) for liquid oceans to form
P waves
Waves that push back and forth, Goes through core
Why does earth have little carbon dixoide in atmosphere?
Has a lot of liquid water and carbon dioxide is very soluble in water
Absorbtion
Photons energy is absorbed (IR)
Scattering
Change in photon direction (optical)
Factors affecting atmosphere
Solar brightening, axis tilt, reflectivity, geen house gases
Albedo
Amount a planet reflects incoming sunlight
Ionization
removal of electron (UV/xray)
Radiation
Photons/light sent into space
Volcanism
eruption of molten rock onto surface
S waves
Waves move transverse to direction of motion (side to side), they don’t go through the core
Techtonics
disruption of a planets surface by internal stressed, as a result of convection currents (mountains or valleys)
The ‘lithosphere’ of a planet is
the rigid rocky material of the crust and upper part of the mantle
What could a decreasing albedo cause?
Gradual warming of climate
How does the cooling of planets vary with size?
- Larger size makes it harder for heat from the inside to escape,
- Larger size means bigger ratio of volume to surface ratio
- Larger size takes longer to cool
Earth’s atmosphere contains just a small amount of carbon dioxide at the present time, because
Carbon dioxide dissolves in water, and now most of it is contained in oceans and carbonate rocks
What is necessary for differentiation to occur in a planet?
- It must be a mixture of materials with different densities
- The materials inside the planet must be able to flow
The cores of terrestrial planets are mostly metal because
Metals are denser and so sank to the centres of planets when they were still molten
Heat escapes from a planet’s surface by thermal radiation. This means that planets radiate almost entirely in the wavelength range of
Infrared
What are the conditions necessary for a terrestrial planet to have a strong magnetic field?
Both a molten metallic core and fairly fast rotation