Our Solar System

1. Our Solar System

2. The Sun • Our Sun is a medium-sized yellow star in the middle of its life cycle. • Its the center of our Solar System and holds objects in orbit by gravitational pull. • More than 1,000,000 Earths can fit inside the Sun. • It’s fueled by nuclear fusion of small atoms to form larger ones, and it’s the only source of energy in the solar system. • It has features: sun spots, solar flares, and prominences.

3. Mercury • Terrestrial planet with a solid rocky surface • Covered with craters • Extreme temperatures (from -170 ºC up to 467 ºC) • Thin atmosphere so its temperatures vary by day and night • Fastest planet to revolve around the Sun, thus named Mercury • No moons … why not?

4. Venus • Terrestrial planet with a solid, rocky surface • Earth’s “twin” in size • Extremely hot temperatures (470 ºC) due to thick atmospheric cloud cover and green house effect. • Retrograde motion (it rotates clockwise) • No moons … why not?

5. Earth • Terrestrial planet with a solid, rocky surface • Frozen caps at North & South Poles • Capable of supporting life due to [C], 70% water, and protective atmosphere • Seasons due to axis tilt • 1 Moon: Luna where we have landed multiple times and sent more than 70 spacecraft

6. Earth’s Moon “Luna” • The moon acts like a mirror; it reflects sunlight to Earth • Phases of the moon occur as the moon revolves around Earth and reflects sunlight. • Tides -- high tide and low tide -- are caused by the moon’s gravitational pull

7. Mars • Terrestrial planet with a solid, rocky surface • Red surface due to [Fe] • Enormous active volcanoes and dust storms • Thin atmosphere • Frozen polar caps like Earth • Liquid water once? • 2 Moons: Phobos and Deimos

8. Asteroids • Made of rock, minerals, and rare elements • More than 100,000 orbit in the “Asteroid Belt” between Mars and Jupiter • Could collide with Earth, but probably won’t • The largest asteroid named Ceres is a dwarf planet • Moons: a few asteroids have moons!

9. Meteors or “Shooting Stars” • Pieces of rock that are falling toward Earth are meteors • They glow brightly as they burn up due to fluid friction • Called “meteoroids” if they are far away, “meteors” if they have a bright tail, and “meteorites” once they hit Earth

10. Jupiter • The largest “gas giant” with no solid surface • Faint rings • Made of elements [H] and [He] with a hot, solid core of [Fe] -- almost a star! • “Red Spot” is a massive storm • 62 Moons: the four largest are named Io, Europa, Ganymede, Callisto, but there are more…

11. Saturn • Second largest gas giant without a solid surface • Famous for bright, icy rings that we can see from Earth with a telescope. The rings have large divisions. • Mostly made of elements [H] and [He] • Less dense than water! • 62 Moons: Titan and Pheobe and more, some orbit in the gaps of the rings

12. Uranus • Gas giant without a solid surface • Made of elements [H] and [He] and water, ammonia and methane • Bluish reflection due to methane (CH4) gas • Faint rings, but the brightest clouds • Axis is turned “sideways” so it has wild seasons • Retrograde motion • 27 Moons: Ariel and more…

13. Neptune • Gas giant without a solid surface • Bluish reflection due to methane (CH4) gas but more vivid than Uranus • Six faint rings • Farthest planet from the Sun, usually • 13 Moons: Triton is the largest and 12 more…

14. Dwarf Planets & Plutoids • Ceres is the largest asteroid in the asteroid belt • Pluto has a solid, icy surface, 3 moons, and it orbits in a tilted plane. Charon is the largest moon of Pluto. • Makemake is smaller than Pluto, but farther • Eris is larger than Pluto, but farther away • More dwarf planets and plutoids are expected to be discovered…

15. Comets • Made of rock, ice and dust • Comets consist of a head, coma, and two tails that point away from the Sun • “Short-period” comets come from the “Kuiper Belt” and orbit the Sun every 200 years or less • “Long-period” comets come from the “Oort Cloud” and take longer to orbit the Sun