Solar System

Mr. SkirbstPhysical Science

Topic 27

http://www.nineplanets.org/

Nebular Theory

- Solar System began as a huge cloud of dust and gas called a nebula

Nebular Theory

- Solar System began as a huge cloud of dust and gas called a nebula

- This nebula condensed to form the sun and planets while spinning around the center

Sun Formation

- Protosun – “developing sun”

Sun Formation

- Protosun – “developing sun”- Most gas gathered in center of

nebula (place of greatest gravity)

Sun Formation

- Protosun – “developing sun”- Most gas gathered in center of

nebula (place of greatest gravity)- Nuclear fusion begins (star is

“born”)

Planet Formation

Protoplanet – “developing planet”

Planet Formation

Protoplanet – “developing planet”-smaller clumps of matter gathered

and formed, orbiting sun

Planet Formation

Protoplanet – “developing planet”-smaller clumps of matter gathered

and formed, orbiting sun- Inner Planets – “rocky” (most

gasses burned off)

Planet Formation

Protoplanet – “developing planet”-smaller clumps of matter gathered

and formed, orbiting sun- Inner Planets – “rocky” (most

gasses burned off)- Outer Planets – “gas giants”

(cooler temperatures)

PlanetsMercuryVenusEarthMarsJupiterSaturnUranusNeptunePluto (now called a Dwarf Planet)

Planetary Motion

“Planet” – Greek for “wanderer”

Planetary Motion

“Planet” – Greek for “wanderer”Earth-centered System:

Ptolemy, Greece 2nd century AD

Planetary Motion

“Planet” – Greek for “wanderer”Earth-centered System:

Ptolemy, Greece 2nd century ADSun-centered System:

Copernicus, 1500’s (planets orbit the sun, not Earth)

Planetary Motion

Elliptical orbits:Johannes Kepller, 1500’s (first to suggest planets orbit in ellipses)

Inertia + Gravity:Isaac Newton, 1600’stwo forces at work with planets

Planetary MotionOrbit:

path around object takes when moving around another object in space

Inertia:motion of object will not change unless acted upon by a force

Planetary MotionGravity:

force attracting two objects with mass

Period of Revolution:one orbit around sun

Period of Rotation:one turn on axis