astronomy notes

Jovian

four planet farthest from the sun that are like Jupiter

Terrestrial

four planets closest to the sun that are relatively small, high density and have been atmospheres

All seven layers

crust, lithosphere, asthenosphere, lower mantle, outer core, and core and atmosphere

Crust

low density

Lithosphere

crust and rigid upper mantle; brittle easily fractures

Asthenosphere

flexible upper mantle; weak/soft rock capable of flow

Magnetic field:

liquid metallic outer core rotates rapidly. magnetic field lines deflect solar wind particles

Photosphere

surface of a star

Most abundant gas

water vapor

Where does salt come from in ocean

the evaporation of ocean water, in large, shallow ponds, using the sun and wind to leave behind and salt crystals

Four terrestrial Planets

mercury, Venus, earth, and Mars

Four Jovian Planets

Jupiter, Saturn, Uranus, and Neptune

Three stages in nebular hypothesis: 

1. Gas and dust form a nebula

2. Nebula collapses into a spinning disk

3. Planets form from the disk

Four sources of geothermal energy:

• Magma

• Hot rocks underground

• Hot groundwater

• Steam from Earth’s interior

Protostar

A forming star; hot and collapsing, but nuclear fusion has not started yet.

Star

A fully formed object where nuclear fusion is happening in the core.

Why is Pluto not a planet

it has not cleared other objects from its orbit.

Moons formation

The Moon likely formed when a Mars-sized object collided with Earth, and the debris came together to form the Moon.