BATTLE OF THE PLANETSEARTH vs JUPITER

Small...Rocky...Liquid water...Breathable Atmosphere...

Huge...Gassy...- 160o C......can you breathe ammonia & methane?

solar nebular theory

• Nebula collapses due to gravity...

• Forms spinning disk with protosun in middle...

• Planetesimals form in disk...

• Protoplanets develop; denser matter gathers closer to center, while less dense matter accretes in the periphery...

• Fusion begins & blows away left-over dust & gas.

Inner & Outer planets• Inner planets

contain large percentages of heavy elements (Fe, Ni).

• Mercury, Venus, Earth & Mars.

• Small, rocky dense.

• Outer planets formed far away from sun (COLD!); kept their gases (H, He) and ices (methane, ammonia).

• Jupiter, Saturn, Uranus, Neptune.

• Large, gassy, low density.

Earth is...SO HOT!!!• HEAT from collisions (all those small

planetesimals banging into each other.

• HEAT from weight of layers piling on top of each other.

• HEAT from decay of radioactive materials within Earth.

DIFFERENTIATION

HEAT caused early Earth materials to be in a molten state.

Dense material (Fe, Ni) sank towards center...

Less dense material (Si) winds on top.

Core...mantle...crust.

Atmosphere• Less dense gases (H, He) rise to top &

become first Earth atmosphere; doesn’t last long (too light to be held by gravity).

• OUTGASSING from volcano eruptions releases water vapor, CO2, N2, CH4, SO2, NH4 to form second atmosphere.

• As life develops, organisms use CO2

during photosynthesis to arrive at present-day O2 atmosphere.

Where did all that water come from?Where did all that water come from?

Maybe from outer space!

• THEORY: Comets struck Earth, bringing ice/water to atmosphere.

• Rain resulting from comet ice/water gave Earth the oceans.

• Salt in oceans comes from land runoff.

• ...or maybe the water came from volcanoes...?

BATTLE OF THE PLANETS

(part II) EARTH vs Mars

Year = 365 daysMt Everest: 8 km highPlenty of malls...All your friends are here

Year = 687 days (you’d only be 8 yrs old...)Olympus Mons: 24 kmPossibility of H2O...