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Explore Mercury

Student Planet Facts



Mercury is the closest planet to the sun. Here are some facts and other places you can find information.

Mercury is a battered and baked planet just larger than Earth's moon. Evidence of heavy bombardment from the chaos of the formation of the solar system is left in the hundreds of craters and resulting lava flows on this small, barren planet. The largest crater is Beethoven at 643 km in diameter and is the largest in the solar system. The largest feature, Caloris Basin, is 1300 km in diameter and was probably caused by an impact from an object larger than 100 km in diameter. Some craters have ice in them (in spite of the fact that Mercury is so hot) because the sun never reaches into the shadows due to the planet's tilt and orbit. With no atmosphere, there is a temperature difference of about 600 degrees between the coldest spots and hottest spots on the planet.

Mercury orbits the sun in about 88 Earth days but takes 58 Earth days to rotate once on its own axis. Because Mercury's rotation takes 58 (earth) days, its year is only a Mercurian day and a half!

How much would you weigh on Mercury?
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Gravity and You
Your weight on Earth is determined by your mass and Earth's mass. Would you weigh more or less on Mercury?

Click for Planet Myths and Lore Planet Names
Why are the planets named for Roman gods? Is there a story or myth about the sun? Click image or here for Planet Myths and Lore.

Blast off on a Planetary Scavenger Hunt! Planetary Scavenger Hunt!
You will need to gather some facts,
compare your data and answer some questions.
Click here to blast off!

Quick Facts about the Mercury
Topic Data
Diameter 4879.4 km
Density 5.43 g/cm3
Mass 3.303 x 1023 kg
Volume 6.084 x 1010 km3
Temperature Range -173° C to 427° C
Atmosphere Some Hydrogen, Helium, Oxygen
Winds None
Moons None
Average Distance from Sun 57,910,000 km
Orbital Period 0 Years, 87 Days, 23.3 Hours
Rotation 58 Days, 15.5 Hours
Tilt 0.00°
Rings None
Composition Iron Core, Silicate Surface
Magnetic Field Slight

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