1. Solar System

2. The Solar System Solar system Consists of the Sun, 8 planets
more than 130 natural satellites & other small bodies
Mostly empty space
Sun
Largest object in our solar system
99.8% of the total mass of our solar system
70 % hydrogen, 28% helium, 2% other metals
Nuclear fusion changes hydrogen to helium & energy
150 million km (93 million miles from Earth)
1 AU - astronomical unit
Each second about 700,000,000 tons of hydrogen
are converted to about 695,000,000 tons of helium
and 5,000,000 tons (=3.86e33 ergs) of energy
in the form of gamma rays.

3. The Sun The picture at left shows the sun
with a huge solar prominence.
Special cameras were used to take the picture.
Do not ever view the sun without
special eye protection or filters.
Staring at the sun can
permanently blind your eyes!

4. We think of the Earth as a huge place.
The sun’s interior
could hold over
1.3 million Earths!
We think of the Earth as a huge place.
The diameter of the Sun is about 100 times
wider than the Earth as can be seen in the
diagram above.

5. Inner planets
Mercury, Venus, Earth, Mars
Known as the terrestrial planets
Small in size & have solid, rocky surfaces
Slow rotation, no rings and
few satellites (moons)
Asteroid belt
Lies between the orbits of Mars & Jupiter
Forms boundary between inner & outer planets

7. Outer planets
First four: Jupiter, Saturn, Uranus, Neptune
Gas giants or Jovian planets
Composed primarily of hydrogen and helium and
generally have low densities, rapid rotation,
deep atmospheres, rings and lots of satellites.

9. Pluto – no longer considered a planet
Small & rocky like the terrestrial planets
Less than 2/3 the size of Earth’s moon
Has a single moon, Charon
May be a double planet instead of a moon & planet

13. How significant are we?