1. The Solar System & Beyond
Chapter 21

2. Measuring Space Distance
Light Year – the distance that light travels in one year
One light year is about 9.46trillion kilometers
Light travels at 300,000 km/s
The farthest objects we can observe are more than 10 billion light years away
Astronomical Units measure distance between the earth and a star

3. Expanding Universe
Astronomical Units (AU) are a unit of measurement used to calculate the distance between the Earth and the sun as well as other stars
Earth is 1 AU from the sun and Mars is 1.54 AU from the sun

4. The Sun The closest star Center of our solar system
Made up of hydrogen and helium atoms that produce light and heat through nuclear fusion

5. Mercury The closest terrestrial planet to the sun
Has a diameter of 4,879 km
Its revolution around the sun takes 88 days
3.2 light minutes from the sun
Temperature range -127ºC to 427ºC

6. Venus 2nd terrestrial planet from the sun
Spins clockwise on its axis (retrograde)
Has the densest atmosphere
6.0 light minutes from the sun
One year revolution is 224 days long
Temperature 464 C

7. Earth 3rd Terrestrial Planet From the Sun Only one that supports life
8.3 light minutes from the sun
12,756 km wide
Revolution 365 days

8. Mars 4th planet from the sun 6,794 km in diameter
Nicknamed the red planet
Temperatures range from -123 C to 37 C
12.7 light minutes from the sun

9. Jupiter Largest gas giant Diameter: 142,984 km
Revolution 11 ¾ Earth years
Temperature -110 C
Radiates more energy than it receives. Distance from sun 43.3 light minutes

10. Saturn Winds blow at 1000 mph at its equator
Width is 120,536 km in diameter
Revolution 29 Earth years and 155 days
Temperature -140 C
Has Icy rings
Light from the sun reaches here in 1.3 light hours

11. Uranus Spins on its side, its poles, possibly due to planet collision
Diameter 51,118 km
Temperature -195º C
One revolution is 83 Earth years and 273 days
2.7 light hours from the sun

12. Neptune Has belts of visible clouds Diameter 49,528km
4.2 light hours from the sun
Has thermal energy center that warms the planet like Jupiter and Neptune
Revolution 163 Earth years
Temperature -200 C

13. Pluto ????? Farthest from the sun, Bizarre Orbit
Demoted from planet August 2006
Diameter 2,390 km
Temperature -225 C
Revolution every 248 Earth Years
5.4 light hours from the sun

14. The Moon
Our moon is a natural satellite – (a non-made man object that follows in a planets orbit)
Moon is named Luna
Moon revolves and orbits the Earth every 28 days.
(a non-made man object that follows in a planets orbit)

15. Me & My Shadow
Umbra - source of light is completely blocked by the object causing the shadow
Penumbra is a solar shadow where the light source is only partially blocked and there is only a partial shadow.

16. Solar Eclipse Happens when the moon comes between Earth and the sun
The shadow of the moon falls on part of the Earth
A total eclipse of the sun doesn’t happen over the whole Earth

17. Lunar Eclipse Happens when Earth comes between the sun and the moon
The shadow of the Earth falls on the moon

18. Meteors