lecture 12 venus: a cautionary tale

Venus surface

Looks smooth but is actually rocky

Venus in relation to the sun

Closer to sun but the think atmosphere reflect sunlight naturally cooling the planet yet it is still the hottest planet

What makes up the yellow atmosphere

Clouds are made form sulfuric acid

What is special about Venus orbit

It spins clockwise (backwards)

Why does Venus spin differently

It’s spin slowed down and reversed from the suns tidal effect on Venus atmosphere

What makes Venus so hot

No tectonic plates to trap co2 in the planet, slurring acid clouds, and pressure is 90x of earth

What causes atmospheric pressure

The weight of air pressing down and depends on the gravity and density of atmosphere

3 steps of the green house effect

Co2 gas is transparent to sunlight, sunlight is absorbed on the surface and released as heat, heat radiation is reflected by co2 gas in the atmosphere

How are co2 and heat related

Co2 is not transparent to heat radiation

Green house gases

Carbon dioxide, methane, nitrous oxide, water vapor

How does earths geological cycle control co2

Co2 dissolves in water, sediment settles on ocean floor, subduction of carbon into earths mantle, volcanic action returns carbon back into atmosphere

How does earths lifecycle control co2

Plants use co2 and expel oxygen, dead plants put carbon into the ground, land erodes into oceans, continue with geological

How does the green house effect on Venus

It’s runaway greenhouse, closer to sun, no subduction of surface into interior, no development of life