Density of Mercury
Written by Fraser Cain
The density of planet Mercury is 5.427 grams per cubic centimeter.
This density makes Mercury the second densest planet in the Solar System after Earth. Just for comparison, the density of Earth is 5.515 g/cm3. So, Mercury is almost as dense as Earth.
And here's the thing. Earth has much more mass than Mercury, and so it has much more gravity to compress it down. If it was uncompressed, Earth would actually have a density of 4 grams/cubic centimeter, while Mercury would only be a little less dense. This means that Mercury is probably 60-70% metal, and 30% silicate. The core of Mercury probably accounts for 75% of the radius of the planet.
Want to compare the density of Mercury to other planets in the Solar System, here's an article about the density of Mars, and the density of Saturn (which is actually less dense than water).
Want more information on Mercury? Here's a link to NASA's World Book on Mercury, and here's NASA's Solar System Exploration Guide to Mercury.
We have also recorded a whole episode of Astronomy Cast that's just about planet Mercury. Listen to it here, Episode 49: Mercury.
Filed under: Astronomy
