1. The Universe
Going the distance

2. What unit would you use to measure….
A basketball
An elephant
The length of a pencil
The width of a pencil
A bacteria
The distance from the Pueblo to London
The distance from here to the moon?
The distance from earth to the sun?

3. The universe is huge!
Scientists use the AU (astronomical unit) to measure distances in the solar system
1 AU is the distance between earth and the sun
1 AU= 149,597,870 km

4. Practice
If the average distance between earth and Jupiter is 5.6 AUs. How many kilometers away is Jupiter?
If 1 mile = 1.6 km. How many miles away is Jupiter?

5. How far are stars?
Even further…. AUs are too small so we astronomers use a unit called
LIGHT YEARS
measure distance not time
measure the distance light travels in 1 year
Light travels fast…is this distance going to be small or large?
* If you could travel in light years you could get to the moon in 8 minutes! The closest star- 4.2 years

6. What’s larger than a light year?
A parsec
1 parsec= 3.6 light-years
Practice: If a star is 50 light-years from earth, how many parsecs is it from earth?

7. Our Solar System The solar system is made of the sun and 8 planets.
Due to the sun’s gravitational pull all other objects revolve around it.

8. Our Galaxy The milky way
contains our solar system
contains over 200 billion other stars and their planets
The diameter of the milky way is approximately 100,000 light years. How many parsecs is that?
It is part of the Local Group made of 3 large galaxies and over 30 small ones

9. Milky Way

10. The Universe All of space and everything in it
Contains billions of galaxies
Galaxies are very far apart
Most of the universe is empty space

11. Multi-step Conversion Practice 1.
Convert 90 seconds to hours.

12. 2.
There are 5280 ft. in 1 mile
Convert 46 inches to miles

13. 3.
Find your age in seconds

14. Homework:
Checking up
1-3- Question 3 was not discussed. Read about it on page 16 and attempt to explain what a parallax is in your own words.
Finish back of worksheet if not already completed
Parts of an Experiment 1-7