# How Do Scientists Know the Mass of Mars?

By Stefan Robert

Scientists know the mass of Mars by determining other pieces of information like the radius and extrapolating from there. Find out how scientists know the mass of Mars with help from an expert in computers, with two degrees in both Computer Science and Applied Mathematics in this free video clip.

### Transcript

Hi, my name is Stefan. Today, I'm going to be speaking on how scientists know the mass of Mars, okay Mars is a planet here, we'll call this M, M for Mars and there's a satellite that travels around Mars, it's actually called Dimos and it travels around it in a circle and this radius I'll call it R and we have the time that it takes to go around it, we'll call that T and we use the formula, T = the square root of 4 Pi squared R cubed/G/M and G is the gravitational pull and M is the mass and now when we solve we get M or the mass of Mars, that's equivalent to, I'm going to use scientific notation, 6.4169 x 10 to the 23 kilograms. And this is our mass of Mars.