1. #5 Introduction to the Solar System

2. Just one star Solar means “sun” so solar system = sun system
Not studying galaxies (billions of stars) or star clusters (millions of stars) yet, only our own solar system.
Solar means “sun” so solar system = sun system
Sun is a star, and is our only one!

3. How to measure something so large?
The distance between stars (and galaxies) is HUGE so we measure it in light years.
Light Years is the distance light will travel in a year
**very important**: a light year is not a time, but a distance!

4. Astronomical Units
Planets in our solar system are closer together, so we can use AU (Astronomical units)
1 AU=Average distance between the Earth and the sun (lazy scientists)
Ex) Mercury is closer to sun (.39 AU)
Ex) Pluto is further from sun (39.5 AU)

6. The Planets Now have 8 planets orbiting the Sun Orbits are elliptical
An ellipse is a shape that can be thought of as a "stretched out" circle or an oval

7. Two major planet groups
The planets are divided into two major groups
1. Terrestrial Planets (Inner Planets)
2. Gas Giants (Outer Planets)
These two groups are separated in the middle by the asteroid belt

8. Gas Giants
Asteroid Belt
Inner Planets

9. Terrestrial Planets Inner Planets (closest to the sun)
Mercury, Venus, Earth, Mars
“Terrestrial” = “Land”
Rocky (dirt-like and metal materials)
Small
Dense
Few moons
No Rings

10. Mercury Venus Earth Mars

11. Terrestrial Planets Mercury The Speediest Planet- Travels
at 29.7 miles/sec.
Venus
The Twin Planet- roughly the same
size as Earth and visible from
Earth without a telescope
Earth
The Home Planet - only planet
known to have an atmosphere
that sustains life
Mars
The Red Planet - an iron surface is
blown around by storms

12. The Gas Giants Outer Planets (Farthest from sun)
Jupiter, Saturn, Uranus, Neptune
Made of gas and liquid
HUGE
Low densities (Saturn floats in water)
Lots of moons
All of them have rings

14. The Gas Giants
Jupiter
The Giant Planet- All the other planets could be squeezed inside of it!
Saturn
The Ringed Planet- has the most (and the largest) rings
Uranus
The Tilted Planet- orbits on its side
Neptune
The Windy Planet- fiercest winds blowing up to 1400 mi/hr. Blue color, Named for the Roman God of the Sea

15. What about poor Pluto? Now considered a dwarf planet
2nd largest dwarf planet we know of
Eris is bigger, Ceres is another
Mass is about 1/5 that of our moon
Made of Ice and Rock (Very Cold)
Orbit is highly elliptical and sometimes dips into Neptune’s orbit

16. The Dwarf Planets

17. Here’s our solar system........

18. So putting it all together.....