Mercury

Atmosphere: Mercury has the thinnest of atmospheres in the solar system. It only has an exosphere that is made up of oxygen, sodium, hydrogen, helium, and potassium.

Planet type: Terrestrial

Physical features:

• Many impact craters from meteoroids and comets

• There are many areas with smooth terrain, as well as cliffs up to a mile high!

Weather: Temperatures are very extreme on Mercury; during the day the surface can reach 800 degrees Fahrenheit while nighttime temperatures can drop to -290 degrees Fahrenheit.

Size: Radius is 1,516 miles or 1/3 the width of Earth.

Speed: Mercury is the fastest of the planets; 1 rotation around the sun (or 1 year) is 88 Earth days.

# of Moons: 0

Other interesting facts:

• Mercury is the 2nd densest planet after Earth!

• Mercury's surface resembles the Earth's moon!