1. Earth Sun Relations
GPH 111

2. What we will cover: Where earth is in relation to the universe
Earth’s rotation and revolution
Terms important to earth’s orbit
How earth’s tilt defines much about our climate

3. Let’s start with the Sun…
>91 million miles
from Earth
11,000° F surface
temperature
98% of total solar
system
Can hold ~1.3
million Earths

4. The rest of the solar system…

5. The rest of the solar system…

6. Where is the Solar System?
Our sun is one of 100 billion stars in our Galaxy

7. Where is our Milky Way Galaxy?
Our galaxy
resides with
roughly 22
other galaxies
of comparable
size in what is
known as the Local Group.
This is Andromeda the largest galaxy in the “Local Group”.

8. How about the Local Group?
The Local Group of galaxies are beginning to merge with the Virgo Cluster that has over 1,000 galaxies, each with roughly 100 billion stars.

9. Alright, so how about the Virgo Cluster?
Virgo cluster is part of a super cluster of galaxies with over 100,000 galaxies, the largest structure in the universe.
(Image courtesy of NASA)

11. OK, enough of that, let’s get closer to home…

12. Earth’s motion… Copy Board Globe Earth-Sun Model Students and Globes
Movie
Diagram

13. Earth revolves around the sun…

14. Where and when could this photo have been taken?
The midnight sun…
Where and when could this photo have been taken?

15. 66.5° N Artic Circle
23.5° N Tropic of Cancer
0° Equator
23.5° S Tropic of Capricorn
66.5° S Antarctic Circle
Show Movie!
Label important latitudes by name and degree on one of the Earths
Label the solstices and equinoxes (include dates)
Label which latitude the sun is directly overhead on these dates
Label where on the planet (for each season) that is experiencing 24 hours of daylight / darkness and 12 hours of daylight and darkness

16. Earth Sun Relations Spring Equinox 3/21 Summer Solstice 6/21
66.5° N Artic Circle
23.5° N Tropic of Cancer
Spring Equinox 3/21
Equal Daylight and Darkness
0° Equator
23.5° S Tropic of Capricorn
66.5° S Antarctic Circle
0° Equator
23.5° N Tropic of Cancer
23.5° S Tropic of Capricorn
Summer Solstice 6/21
24 hour darkness 66.5° S
24 hour daylight 66.5° N
Winter Solstice 12/21
24 hour darkness 66.5° N
24 hour daylight 66.5° S
0° Equator
Fall Equinox 9/21
Equal Daylight and Darkness

17. Solar energy distribution on Earth…

18. Things to know… Facts about the sun
Names and number of planets in the solar system
Number of stars in the Milky Way Galaxy
Number of galaxies in the local group
DIAGRAM AND LABEL EARTH SUN RELATIONS
Where on our planet receives the most energy? Where receives the least? (at the top of the atmosphere)
Help: Chapter ES
Sketch the diagram – Label important latitudes by name and degree
Label the solstices and equinoxes (include dates)
Label which latitude the sun is directly overhead on these dates
Label where on the planet (for each season) that is experiencing 24 hours of daylight / darkness and 12 hours of daylight and darkness