Our Solar System Planets
There are eight planets in our solar system including Earth. So far, no life as we know it exists on any planet other than our own.
Mercury

- Size:
Two-fifths the size of Earth in diameter; second smallest in the solar system
- Diameter:
3,032.4 miles (4,880 km)
- Surface:
Covered by a dusty layer of minerals (silicates), the surface is
made up of plains, cliffs, and craters
- Atmosphere:
A thin mixture of helium (95%) and hydrogen
- Temperature:
Mercury alternately bakes and freezes, depending on what side is lit by the Sun. The sunlit
side can reach up to 950 degrees F (510 degrees C) and the dark side can drop as low as -346 degrees F (-210 degrees C)
- Rotation of its axis:
59 Earth days
- Rotation around the Sun:
88 Earth days
- Your weight:
If you weigh 100 pounds on Earth, you would weigh 38 pounds on Mercury.
- Distance from Earth:
57 million miles, at the closest point in its orbit
- Mean Distance from Sun:
36 million miles (57.9 million km)
- Satellites:
0
- Rings:
0
Venus

- Size:
About 650 miles smaller in diameter than Earth
- Diameter:
7,519 miles (12,100 km)
- Surface:
A rocky, dusty, waterless expanse of mountains, canyons, and plains, with a 200-mile river of hardened lava
- Atmosphere:
Carbon dioxide (95%), nitrogen, sulfuric acid, and traces of other elements
- Temperature:
Ranges from 55 degrees F (13 degrees C) to 396 degrees F (202 degrees C) at the surface
- Rotation of its axis:
243 Earth days
- Rotation around the Sun:
225 Earth days
- Your weight:
If you weigh 100 pounds on Earth, you would weigh 88 pounds on Venus.
- Distance from Earth:
At its closest, Venus is 26 million miles (41,840,000 km) away
- Mean Distance from Sun:
67.24 million miles (108.2 million km)
- Satellites:
0
- Rings:
0
Earth

- Size:
Four planets in our solar system are larger and four are smaller than Earth
- Diameter:
7,926.2 miles (12,756 km)
- Surface:
Earth is made up of water (70%), air, and solid ground. It appears to be the only planet with water
- Atmosphere:
Nitrogen (78%), oxygen (21%), other gases
- Temperature:
- Rotation of its axis:
23 hours, 56 minutes, 4 seconds
- Rotation around the Sun:
365.2 days
- Your weight:
- Distance from Earth:
- Mean Distance from Sun:
92.9 million miles (149.6 million km)
- Satellites:
1
- Rings:
0
Mars

- Size:
About one-half the size of Earth in diameter
- Diameter:
4,194 miles (6,794 km)
- Surface:
Canyons, dunes, volcanoes, and polar caps of water ice and carbon dioxide ice
- Atmosphere:
carbon dioxide (95%)
- Temperature:
as low as -305 degrees F (-187 degrees C)
- Rotation of its axis:
24 Earth hours, 37 minutes, 23 seconds
- Rotation around the Sun:
687 Earth days
- Your weight:
If you weigh 100 pounds on Earth, you would weigh 38 pounds on Mars.
- Distance from Earth:
35 million miles (56 million km) at the closest point in its orbit
- Mean Distance from Sun:
141.71 million miles (227.9 million km)
- Satellites:
2
- Rings:
0
Jupiter

- Size:
11 times the diameter of Earth
- Diameter:
88,736 miles (142,800 km)
- Surface:
A hot ball of gas and liquid
- Atmosphere:
Whirling clouds of colored dust, hydrogen, helium, methane, water, and ammonia. The Great Red Spot
is an intense windstorm larger than Earth.
- Temperature:
-234 degrees F (-148 degrees C) average
- Rotation of its axis:
9 hours and 55 minutes
- Rotation around the Sun:
12 Earth years
- Your weight:
If you weigh 100 pounds on Earth, you would weigh 265 pounds on Jupiter.
- Distance from Earth:
At its closest, 370 million miles (591 million km)
- Mean Distance from Sun:
483.88 million miles (778.3 million km)
- Satellites:
63
- Rings:
4
Saturn

- Size:
About 10 times larger than Earth in diameter
- Diameter:
74,978 miles (120,660 km)
- Surface:
Liquid and gas
- Atmosphere:
Hydrogen and helium
- Temperature:
-288 degrees F (-178 degrees C)
- Rotation of its axis:
10 hours, 40 min, 24 sec
- Rotation around the Sun:
29 1/2 Earth years
- Your weight:
If you weigh 100 pounds on Earth, you would weigh 107 pounds on Saturn.
- Distance from Earth:
744 million miles at the closest point
- Mean Distance from Sun:
887.14 million miles (1,427 million km)
- Satellites:
31
- Rings:
1,000?
Uranus

- Size:
4 times larger than Earth in diameter
- Diameter:
32,193 miles (51,810 km)
- Surface:
Little is known
- Atmosphere:
Hydrogen, helium, and methane
- Temperature:
uniform temperature of -353 degrees F (-214 degrees C)
- Rotation of its axis:
17 hours
- Rotation around the Sun:
30,685 days or 84 Earth years
- Your weight:
Not known
- Distance from Earth:
At the closest point, 1,607,000,000 miles
- Mean Distance from Sun:
1,783.98 million miles (2,870 million km)
- Satellites:
27
- Rings:
11
Neptune

- Size:
Almost 4 times the size of Earth in diameter
- Diameter:
30,775 miles (49,528 km)
- Surface:
A liquid layer covered with thick clouds and with constant, raging storms
- Atmosphere:
Hydrogen, helium, methane, and ammonia
- Temperature:
-353 degrees F (-214 degrees C)
- Rotation of its axis:
16 hours and 7 minutes
- Rotation around the Sun:
165 Earth years
- Your weight:
Not known
- Distance from Earth:
2,680,000,000 miles at closest point
- Mean Distance from Sun:
2,796.46 million miles (4,497 million km)
- Satellites:
13
- Rings:
4
Pluto

- Size:
Less than one-fifth the size of Earth in diameter
- Diameter:
1,423 miles? (2,290 km?)
- Surface:
A giant snowball of methane and water mixed with rock
- Atmosphere:
Methane
- Temperature:
between -369 degrees and -387 degrees F (-223 degrees and -233 degrees C)
- Rotation of its axis:
6 days, 9 hours, 18 minutes
- Rotation around the Sun:
248 Earth years
- Your weight:
Not known
- Distance from Earth:
At the closest point, 2.67 billion miles
- Mean Distance from Sun:
3,666 million miles (5,900 million km)
- Satellites:
1
- Rings:
?