lecture 8 Flashcards
lecture 8 material
What is space debris?
basically space garbage
- space craft materials, dead satellites, etc
- travelling very quick to remain in orbit; thus will destroy satellites and remain in orbit for many years
- military makes it worse by destroying asteroids
how to fix
- cant do much
- ESA made a petition to make sure industries are responsible for their debris; cleaning it up, and making sure everything returns to earth
How much has space exploration (NASA) impacted USAs economy?
- genearted 3x its cost
- created many jobs
more spin offs
- water filtation
- reducing size and mass of circuits (phones)
- temper foam originally made for astronaut comfort, now used in mattresses
Why is venus so unlike earth?
- cannot see the surface bc of a reflective cloud
- very bright bc of proximity to sun
- spacecraft must be used to see underneath the clouds
Name venus’ physical characteristics
- somewhat similar to earth
- atmosphere is 90x thicker than earths (runaway greenhouse: large amounts of CO2 stuck in atmosphere, making it very hot (450c))
- acid rain, little wind
- lowland; no plate tectonics (stess caused surface to crack and uplifting mountains)
- tall mountaints and volcanoes (active)
- large crators = young surface (500million years)
- lava beneath surface creating cracks and a lava dome
What is so different about venus’ atmosphere?
it contains 96% CO2 and 3.5% Nitrogen
- earths oceans dissolve CO2
- nothing from surface gets into space
- cloudy nights are warmer
- convection rises 50km and descends at poles
sulpheric acid clouds
- most hospitable place on venus
- any life on venus would be in these clouds
What is venus’ rotational pattern?
rotates once every 243 days, east to west
roates around the sun every 225 days
- very big collision messed up its orbit
Venus’ evolution history
- likely had water on its surface
- looked similar to earth; proximity to sun evapourated water, infusing atmosphere with CO2, leading to runaway greenhouse effect
Missions to the outer solar system
Jupiter, Saturn, Uranus, and Neptune
Pioneers 10 and 11, voyagers 1 and 2
- need much more energy
- the fact that we didnt know what was out there caused hesitation; harsh environments, dont know if technology would survive
- difficult to reach outer planets, needs improved and bigger comunication devices
Explain the basic information known about Jupiter
- had an extensive amount of heat from its formation, which it is still radiating, allowing us to see its colour
- red spot: a persistant high pressure region, producing a cyclo wind storm
- features form and move around the dot - has a very high density; saturn would float in a bathtub
- ammonia crystals within clouds; what colour we see bc technically jupiter should be colorless considering its hydrogen composition
What are the gas and ice giants?
Gas giants
- Jupiter
- Saturn
Ice giants
- Neptune
- Uranus
composition includes hydorgen, helium, ices, and rocks; elements having formed preferentially with hydrogen
- volatile materials were present in the formation of solar system
Explain planetary interiors of outer planets
Jupiter and Saturn
- share similar intense pressure within itself (bigger the planet, higher the pressure)
- further into atmosphere, gas turns to liquid, then liquid turns into metal
- molecular hydrogen → metallic hydrogen (majority) → ice → rock
Uranus and Neptune
- not as large, less pressure
- Molecular hydrogen →ice → rock
- more ice than gass
the cores of these worlds are small and not easily defined but uranus and neptunes cores are substantially larger than jupiters and saturns
Explain what you know about magentic fields
- helps us survive here on earth by protecting us from the harsh radiaiton of the sun
- Jupiter was known to have one for a long time, other planets fields were just recently detected
- the radiaition emitted when high-speed electrons are accelerated by a magnetic field is called synchrotron radiation
What is saturns cloud structure?
- there are many bands, zones, and stroms
- hexagon cloud formation at north pole
- jet stream interactions
- 10k - 15k m above surface
Neptunes composition
- its colour in pictures is exaggerated
- caused by scattering of sunlight in upper atmosphere - high altitude clouds
- 4x diamter of earth
- water vapour based
- narrow clouds made of methane, casting a shadow
What are the differences between jovian planets and terrestrial planets?
- density, composition, size, location
- all jovian planets have rings and numerous moons (some being larger than terrestrial planets)
- 250 moons orbit jovian planets
- 3 moons orbit terrestrial planets (small)
