1. Uranus

2. Uranus
Average distance from the sun = about 1 billion 710 million miles (1,710,000,000)
1 year = 84 Earth years
1 day = Earth hours
Radius = 4 times Earth’s radius
Mass = 14.5 times Earth’s mass
Average temp at cloud tops = -330 F
Atmospheric composition
82.5% Hydrogen
15.2% Helium
2.3% methane
Some water vapor

3. Uranus The 4th most massive planet in the Solar system
Discovered in 1781 with the aid of a telescope
Like Saturn and Jupiter, it has belts and zones
Methane and water vapor form ice crystals in the cloud tops
Methane absorbs red light, giving Uranus its blue-green color

4. A Unique axis of rotation

5. Its axis of rotation is tilted 98o This produces dramatic seasons
It also rotates on its axis in a clockwise direction (like Venus)
Recall this is called retrograde motion
It may have been part of a massive collision that caused the axis to tilt in this way

6. The Interior of Uranus
The interior most likely is separated into 3 distinct layers
Outer layer: liquid Hydrogen and Helium
Middle layer: highly compressed water
Some methane and ammonia
Inner core is dense rock

8. Rings and Moons of Uranus
Uranus has 10 known rings
They were discovered accidentally when they blocked the light from a star behind it
This is known as occultation
They orbit in the plane of the equator
Most of its moons orbit in this plane also
There are 5 major moons ( of 27 total known)
They from km in diameter

10. Miranda Miranda is the smallest of the 5 major moons
After a high energy impact, large pieces of the moons ice-rock crust broke off
Eventually they were gravitationally attracted back to the planet
Today, we see a patchy surface

12. Neptune

13. Neptune The 3rd largest planet in the solar system
Very similar to Uranus
It is blue in color and has belts and zones
High wind speeds
Up to 2000 km/hr
Rotational axis is tilted 30 degrees

14. Key Stats
Average distance from the sun = 2 billion 700 million miles (2,700,000,000)
1 year = Earth years
1 day = hours
17.1 times the mass of Earth
Radius is 24,764 km (3.88 times larger than Earth’s radius
Average temp at cloud tops -360F
Atmospheric composition
79% Hydrogen
18% Helium
3% methane

15. The Discovery of Neptune
Neptune was predicted to exist by looking at the orbit of Uranus
Uranus was moving slightly different than should have been according to Newton’s laws of motion
This was due to the gravitational influence of Neptune

16. Neptune’s atmosphere Belts and zones show differential rotation
There are also storm systems
The Great Dark Spot
Methane ice crystals have been detected in the upper cloud layer giving Neptune a blue-green color

18. Neptune’s interior Very similar to the interior of Uranus
The interior most likely is separated into 3 distinct layers
Outer layer: liquid Hydrogen and Helium
Middle layer: highly compressed water
Some methane and ammonia
Inner core is dense rock

20. Rings and Moons of Neptune
Neptune also has rings
They are similar to those of Uranus
Low albedo
Thin
It has 13 known moons
Most are captured objects
Triton is the largest

22. Triton Has a retrograde orbit Is most likely a mixture of rock and ice
Has a thin Nitrogen atmosphere
Tidal forces from Neptune may has melted the interior
They may also have changed its surface features
It appears to have frozen lakes and ice geysers expelling nitrogen
Plumes of gas 8 km high have been observed
It surface temp is -395F
The coldest body yet studied

24. The Roche Limit
If an moon gets too close to a planet, it can be pulled apart
This specific distance is called the Roche limit
Triton is slowly drifting closer to Neptune
Eventually, it will breech the Roche limit and be destroyed
Its pieces will most likely end up as a ring around Neptune