The Inner Planets

Mercury

• Mercury has been struck by many asteroids.
• It has no atmosphere, which prevents the craters from eroding away.
• Is the smallest planet.
• Is the planet closest to the Sun.

Venus

• Venus was named after a Roman goddess.
• Venus has the most volcanoes in the solar system, ranging from 100,000 to 1 million.
• The clouds are made out of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid.
• Surface temperatures can rise to 456 degrees Celsius (860 degrees Fahrenheit).

Mars

• Has a much lower pressure than Earth's.
• Mars appears red because of the iron oxide in the soil.
• Mars is home to the largest canyon in the solar system, Valles Marineris, which is 4,000 kilometers long.

Asteroids

• Asteroids are irregularly shaped because they have no gravity.
• Most of the asteroids are located in between Mars and Jupiter.
• When large asteroids come crashing down to Earth, it can cause some creatures to go extinct.