The Solar System

Objectives

1. Describe how the solar system formed.

2. Summarize the main characteristics of each of the 8 planets as well as other objects in our solar system.

3. Explain the laws that govern the motion of the planets (Kepler’s Laws).

Formation of the Solar System

• 4.6 billion years ago, the same nebula that formed the sun also lead to the formation of the planets.

• This material is what’s left over after an ancient star went supernova.

Formation of the Solar System• Gravity pulled this nebular material together into

a rotating flat disc.• Debris collects into ‘planetesimal’ bodies.

Kepler Space Telescope

• Launched in March 2009, the Kepler Space Telescope is searching for planets in orbit of other stars.

• Thanks to Kepler scientists, we now have direct evidence of many extra-solar planets.

Launch video

Our Solar System

The Sun

Facts about the Sun• Almost 1 million miles in

diameter

• Temperature: Surface = 5500 C Core = 15.7 million C

• Rotates every 25 hrs.

• Mostly hydrogen (73.5%) and helium (24.9%)

•

Mercury

Facts about Mercury• 4878 km in diameter

• Temperature: Surface = 175 C

• 1 day = 58.7 Earth days 1 year = 88.96 days

• No moons, no rings•

Venus

Facts about Venus• 12,104 km in diameter

• Temperature: Surface = 450 C

• 1 day = 243 Earth days 1 year = 224.7 days

• No moons, no rings•

Earth

Facts about Earth• 12,756 km in diameter• Temperature: Surface = 15 C• 1 day = 24 hours 1 year = 365.25 days• 1 moon, no rings•

MarsV

ideo

of M

ars

Facts about Mars• 6787 km in diameter

• Temperature: Surface = -40 C

• 1 day = 24.6 hours 1 year = 687 days

• 2 moons (Phobos & Deimos), no rings

•

More Mars Photos

Phobos Deimos

Landing of rover ‘Opportunity’

Water on Mars?

Life on Mars?

Jupiter

Facts about Jupiter• 142,796 km in diameter

• Temperature: • Cloud top = -150 C

• 1 day = 9.8 hours 1 year = 11.86 Earth years

• 63 moons, 1 faint ring•

Jupiter and Comets

Saturn

Facts about Saturn• 120,660 km in diameter

• Temperature: Surface = -185 C

• 1 day = 10.2 hours 1 year = 29.46 years

• 61 moons, >30 rings•

Saturn and the Earth

More about Saturn• Currently, the

Cassini-Huygens mission is investigating the Saturn system.

• Jan. 2005, Huygens landed on Titan.

• Cassini Landing on Titan

Uranus

Facts about Uranus• 51,118 km in diameter

• Temperature: Surface = -214 C

• 1 day = 17.9 hours 1 year = 84.1 years

• 27 moons, 13 rings•

Uranus Video

Neptune

Facts about Neptune• 48,600 km in diameter

• Temperature: Surface = -225 C

• 1 day = 19.1 hours 1 year = 164.8 years

• 13 moons, 5 rings•

Neptune Video

Why isn’t Pluto a planet??Pluto Video

Other Objects in our Solar System

• Asteroids- small rocky body orbiting the sun.

• Comets- icy body, orbiting the sun (has a visible tail).

• Dwarf Planets- small ‘planet-like’ objects orbiting the sun.

• Meteoroid- tiny rocky object in space• Meteor- a meteoroid that has entered the atmosphere• Meteorite- a meteor that has hit the ground

•

Solar System Summarized

NASA Images Set to Music