As we continue to work toward an eventual manned mission to Mars, the minds at NASA are hard at work figuring out exactly what we’ll find once we get there. Now we also have an inkling for what we’ll find underneath the surface, too.
The space agency notes that a new map of Mars' gravity, created using data from three NASA spacecraft, is the most detailed to date in regard to the planet’s largely hidden interior. The data were compiled using Doppler intel from the Mars Global Surveyor (MGS), Mars Odyssey (ODY) and the Mars Reconnaissance Orbiter (MRO). The data are created by recording the slight variations caused by the planet’s makeup (i.e. stronger gravity over a mountain, weaker over a canyon).
"Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient," Antonio Genova of the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, told NASA. "The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet's gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars. Furthermore, the improved resolution of our gravity map will help us understand the still-mysterious formation of specific regions of the planet.”
NASA says the latest gravity map brought several pieces of intel, including the fact that Mars has a liquid outer core of molten rock. That was seemingly confirmed by analyzing tides in the Martian crust and mantle caused by the gravity from the sun and the planet’s two moons. The team also observed how the planet's gravity changed over 11 years (a full cycle of solar activity), as well as how mass moves between the planet’s poles.