1. ASTRONOMY & SPACE SCIENCE

2. Solar System

3. What is Astronomy? 1. Astronomy is the study of the universe.
This includes planets, stars, galaxies, black holes, moons, meteors, comets, asteroids and all of the matter that exists in space.
2. Astronomers are people who observe & study space.

4. Size and Scale of Our Universe
It is important to consider scale when we think about the universe.
Stars appear to be very small when viewed from Earth, but they are actually very large, some, like our sun, are bigger than Earth.

5. The Scale of Our Solar System

6. The Scale of Our Universe

7. Our Galaxy and Scale Our Milky Way galaxy is huge.
Let's now pretend that our galaxy is a kid's sandbox, and our sun is a grain of sand in a sandbox.
The Earth is a dust speck near the grain of sand, too small to be seen without a microscope.
If our sun were a grain of sand in this sandbox representing the Milky Way galaxy, the sandbox would be somewhat oval and flat, and would be about 20 feet in diameter.
The sand would be about 1 foot thick in the center, and thinner towards the edges.

8. Distance in Space
Distance in space outside of our solar system is measured in light years
Light Years- the distance light travels in a year = 5.88 trillion miles. IT IS NOT TIME!

9. Astronomical units (AUs)
Measure distances among the planets in the solar system: 1 AU = 150 million km= 93 million miles, the avg distance from Earth to the Sun

10. Objects that orbit the Sun
planets – a planet must orbit the Sun, have a sphere shape and have a mass much larger than the total mass of all other objects
dwarf planets – sphere-shaped object that orbits the Sun but does not have more mass than the objects in nearby orbits
asteroid – millions of small, rocky objects that orbit the Sun in an asteroid belt

11. Objects that orbit the Sun
comet – made of gas, dust and ice and moves around the Sun in an oval- shaped orbit
meteoroids – debris left by colliding asteroids or dispersing comets

12. The Planets

13. Planets are classified according to their location in the solar system
Planets are classified according to their location in the solar system. Inner planets are those with orbits between the Sun and asteroid belt Outer planets orbit outside the asteroid belt. Terrestrial planets - made mainly of rocky material Giant gaseous planets are made mainly of ice and gas.

14. The Inner Planets
Terrestrial Planets: They are solids & close to the sun
The materials that make them can be a solid at high temperatures.

15. Mercury Planet closest to Sun Has no moons Made of iron
The smallest planet and 2nd hottest planet

16. Venus
Second from Sun and similar to Earth in size and mass (Earth’s Twin)
Hottest planet in the solar system due to its thick atmosphere
Its atmosphere creates a monstrous greenhouse effect

17. Earth Third planet from the Sun 1 moon- Luna
water exists on Earth as solid, liquid and gas

18. Mars Fourth planet from the Sun
called the red planet because of rust- evidence that water is or was once present
Home to the largest volcano in the solar system

19. The Outer Planets: Gas Giants or Jovian Planets
They are made of gas. They are NOT solid
They have rings
They have a much larger mass and have more moons than the inner planets

20. Jupiter Largest planet in solar system; fifth from Sun
Great Red Spot- a storm system similar to a hurricane that is over 400 years old.
has at least 60 moons

21. Jupiter’s Rings

22. Saturn Sixth planet from Sun, second largest in solar system
Rings are the largest of the gas giants. They are made of icy particles.
31 moons

23. Uranus Seventh planet from Sun; large and gaseous
Made of hydrogen and methane- gives planet its blue-green color
Rotates on its side- one side points toward the sun & the other is in complete darkness for part of the year.

24. Uranus’ Rings

25. Neptune: Big Blue World
Eighth planet from Sun
Frozen surface
Methane gas makes Neptune appear blue
Neptune and Pluto’s orbits overlap causing Neptune to sometimes orbit beyond Pluto

26. Neptune’s Rings

27. Pluto: The Dwarf Planet
Made of rock and ice
No longer a “planet” but a dwarf planet

28. The Asteroid Belt
Asteroid- Small, rocky bodies that revolve around the sun
made of leftovers from the formation of the universe
Asteroid Belt- a region of space between Mars and Jupiter