1. Do Now: Name all of the planets in our solar system.
Notepack 25
Aim: The Solar System
Do Now: Name all of the planets in our solar system.

2. What is a Solar System?
A solar system is a group of celestial bodies (star, planets, moons, comets, asteroids) that interact with each other through gravitation forces.

3. What is our Solar System made up of?
Our solar system is made up of:
One star (the Sun)
8 planets (9 if you include Pluto)
170 moons
45,000 huge asteroids, and countless small ones.
Unknown number of comets
It is divided into 5 sections:
The inner solar system – The Rocky Planets (Terrestrial Planets)
The asteroid belt
The outer solar system – The Gas Giant Planets (Jovian Planets)
the Kuiper belt
Oort cloud

4. The Sun The Sun is located in the center of our solar system.
It is an average yellow star.
It uses a fusion reactor to convert Hydrogen into Helium, which releases huge amounts of energy.
It provides the solar system with energy.
It takes 26 Earth days for the Sun to spin (rotate) 1 time.

5. The Planets – The Inner Planets – The Terrestrial Planets
The four inner planets of the solar system are solid and made of rock. (They are called Terrestrial planets.)
They orbit (revolve) around the Sun in a counter clockwise direction.

6. The Planets – The Inner Planets (cont)
Mercury is the smallest of the planets in our solar system.
It is also the closest to the Sun.
It has no atmosphere or moon.
It takes 88 days for it to orbit (revolve) around the Sun.
It takes 59 days for it to spin (rotate) once.

7. The Planets – The Inner Planets (cont)
Venus is similar to the size of the Earth. (Earth’s Twin)
It is the second closest to the Sun.
It has very thick atmosphere and has no moon.
It takes 225 days for it to orbit (revolve) around the Sun.
It takes 243 days for it to spin (rotate) once.

8. The Planets – The Inner Planets (cont)
Earth is the third closest to the Sun.
It has an atmosphere and has one moon.
Only place in the solar system that has liquid water.
So far, only planet that has life on it.
It takes 365 days for it to orbit (revolve) around the Sun.
It takes 24 hours for it to spin (rotate) once.

9. The Planets – The Inner Planets (cont)
Mars is half the size of the Earth.
It is the fourth closest to the Sun.
It has very thin atmosphere and has 2 moons.
It takes 687 days for it to orbit (revolve) around the Sun.
It takes 24.5 hours for it to spin (rotate) once.
Phobos and Deimos

10. The Planets – The Outer Planets – The Gas Giants or Jovian Planets
Jupiter is the largest planet in the solar system. You can fit 990 Earths inside Jupiter.
It is the fifth closest to the Sun.
It has very thick atmosphere and has more than 16 moons.
It is made of gas and believed to have no solid ground.
It takes 12 years for it to orbit (revolve) around the Sun.
It takes 10 hours for it to spin (rotate) once.

11. The Planets – The Outer Planets
Saturn is the second largest planet is the solar system. You can fit 764 Earths inside it.
It is the sixth closest to the Sun.
It has very thick atmosphere, more than 18 moons and rings.
It is made of gas and is less dense than water.
It takes 30 years for it to orbit (revolve) around the Sun.
It takes 10 hours for it to spin (rotate) once.

12. The Planets – The Outer Planets
Uranus is another gas giant. You can fit 63 Earths inside it.
It is the seventh closest to the Sun.
It has very thick atmosphere, more than 21 moons and rings.
Unlike the other planets, Uranus spins on it side..
It takes 84 years for it to orbit (revolve) around the Sun.
It takes 17 hours for it to spin (rotate) once.

13. The Planets – The Outer Planets
Neptune is the last gas giant the solar system. You can fit 58 Earths inside it.
It is the eighth closest to the Sun.
It has very thick atmosphere, more than 8 moons and rings.
It takes 165 years for it to orbit (revolve) around the Sun.
It takes 16 hours for it to spin (rotate) once.

14. The Planets – The Outer Planets
Pluto is not a planet but a planetoid.
It is the ninth object orbiting the Sun.
It is thought to be similar to mercury and has a moon.
Its orbit is not in the same plane as the rest of the planets (it’s slightly off).
It takes 248 years for it to orbit (revolve) around the Sun.
It takes 6 days for it to spin (rotate) once.

16. The Asteroid Belt
Separating the inner planets and the outer planets is an area of rocky debris called the Asteroid Belt.
Is it believed that there was a planet between Mars and Jupiter that exploded or collided with another planet. All that remains is large pieces of rock that obit the Sun.
The Asteroid Belt is the source of many meteors.
Some asteroids are as large as 564 miles across.

17. The Kuiper Belt and The Oort Cloud
The Kuiper Belt and the Oort cloud are regions past the orbits of Neptune.
The Kuiper Belt contains icy planetoid such as Pluto and Chiron (Pluto’s moon).
It act similar to the asteroid belt.
The Oort Cloud is where comets are formed.
Spherical shape
Engulfs the whole solar system.

18. Minor Objects in Space
Comets are balls of ice and rock that orbit the Sun.
They originate from the Oort cloud at the edge of the solar system.
A tail is formed as the comet approaches the Sun.
The tail is longest when the comet is closest to the Sun.
The tail is always pointing away from the Sun
A comet collision is credited for killing the dinosaurs.

19. Meteors and Meteorites
Meteors and Meteorites are space debris that is mostly made of iron and rock.
Meteors float freely is space
Meteorites are meteors that are caught in a planet’s gravity and free to the ground.
About 20,000 meteorite strikes per year.
Most of the time, meteorites burn up completely before it strike the ground.
If large enough, Meteorites can leave a crater.