There is not much known about Mercury or its surface, except that it is similar to the moon in appearance and its composition consists of primarily molecular oxygen, sodium and hydrogen. There are also small amounts of h... More »

Mercury's revolution is 88 Earth days. A planet's revolution is the time it takes to make one complete orbit around the sun. This is different than Mercury's rotation period, which is the time it takes this planet to spi... More »

The surface gravity on Mercury is 3.7 meters per second squared, which is 38 percent of the surface gravity on Earth. Surface gravity is typically measured in acceleration units. More »

Mercury's atmosphere is primarily made up of oxygen, potassium, sodium, helium and hydrogen. The atmosphere on Mercury is made up of atoms that are launched from the planet's surface from micrometeoroid impacts and solar... More » Science Astronomy Planets

During 2014, Mercury was in retrograde for three periods. The dates were February 6 to 28, June 7 to July 1 and October 4 to 25. More » Science Astronomy

The average temperature on Mercury is 332 degrees Fahrenheit. The hottest temperatures on the planet can reach 801 degrees Fahrenheit, and temperatures can drop to as low as -279 degrees Fahrenheit. More » Science Astronomy

In astrology, Mercury in Leo is one of the 12 alignments of the planet Mercury. Those born during this time tend to be confident and often become figures of authority. More » Science Astronomy