A new gravity map of Mars that shows the thickness of the Martian crust based on gravity measurements from Martian orbiters, reveals a crust that is less dense and shows less variation than earlier maps. “The researchers mapped the density of the Martian crust, estimating the average density is 2,582 kilograms per meter cubed (about 161 pounds per cubic foot). That’s comparable to the average density of the lunar crust. Typically, Mars’ crust has been considered at least as dense as Earth’s oceanic crust, which is about 2,900 kilograms per meter cubed (about 181 pounds per cubic foot).”
NASA has released a free-air gravity map of the Moon: “If the Moon were a perfectly smooth sphere of uniform density, the gravity map would be a single, featureless color, indicating that the force of gravity at a given elevation was the same everywhere. But like other rocky bodies in the solar system, including Earth, the Moon has both a bumpy surface and a lumpy interior. … The free-air gravity map shows deviations from the mean, the gravity that a cueball Moon would have.” Gravity data comes from the GRAIL mission, with the digital elevation model provided by the Lunar Reconnaissance Orbiter laser altimeter. Image credit: NASA’s Goddard Goddard Space Flight Center Scientific Visualization Studio.