Inner Planets Quiz

The Inner Planets: Mercury, Venus, Earth, and Mars

• Mercury is 46 million to 70 million kilometers away from the Sun, with temperatures ranging from -300 to 800 degrees Fahrenheit.
• A Mercurian year lasts 88 Earth days, but a day on Mercury is about 1407 hours long.
• Mercury is named after the Roman god of commerce, Mercurius, and is the smallest planet in the solar system, shrinking every year.
• Venus is the second inner planet, 108 million kilometers from the Sun, with a year lasting 224 Earth days and a day lasting 5830 hours.
• Venus is the hottest planet in the solar system, with an average temperature of 870 degrees F, and it spins clockwise, unlike other planets.
• Earth, the third inner planet, is 150 million kilometers from the Sun, with a year lasting 365 days and a day lasting 24 hours.
• About 70% of Earth's surface is water, and it has one large satellite, the Moon.
• Mars, the fourth inner planet, is 228 million kilometers from the Sun, with a year lasting 687 Earth days and a day lasting about 24.5 hours.
• Mars is known as the red planet, has a diameter of about 6800 km, and has two moons.
• Inner planets formed from smaller dust and particles in the original solar nebula, with high temperatures allowing metal and rock to condense.
• The inner planets are composed of silicates and metals, with denser compositions compared to the outer planets made of gas, ice, and rocks.
• The inner solar system consists of the four inner planets and the asteroid belt, with the frost line marking the boundary between the inner and outer solar systems.