NASA has released a new gravity map of Mars - one that allows a detailed look at the Red Planet's hidden interiors. Lead author, Antonio Genova of the Massachusetts Institute of Technology (MIT) said that gravity maps allow them to see inside a planet - much like an X-ray.
Genova said that the new gravity map will help researchers better understand the planet's gravity anomalies, which will, in turn, help mission controllers insert spacecrafts more precisely into the orbit about Mars.
Furthermore, the improved resolution of this gravity map will help the researchers understand the still-mysterious formation of specific regions of the planet. The improved resolution of the new gravity map suggests a new explanation for how some features formed across the boundary that divides the relatively smooth northern lowlands from heavily cratered southern highlands.
The team also confirmed that Mars has a liquid outer core of molten rock. The researchers reached the conclusion after analysing tides in the Martian crust and the mantle caused by the gravitational pull of the sun and the two moons of Mars.
The team also observed how Mars' gravity had changed over 11 years - the period of an entire cycle of solar activity -in order to infer the massive amount of carbon dioxide that freezes out of the atmosphere onto a Martian polar ice cap when it experiences winter. The team also observed how that mass moves between the South Pole and the North Pole with the change of season in each hemisphere.
The map was derived using Doppler and range tracking data collected by NASA's Deep Space Network from three NASA spacecraft in orbit around Mars, the Mars Global Surveyor (MGS), the Mars Odyssey (ODY) and the Mars Reconnaissance Orbiter (MRO). Genova said:
"With this new map, we've been able to see gravity anomalies as small as about 100 kilometers (about 62 miles) across, and we've determined the crustal thickness of Mars with a resolution of around 120 kilometers (almost 75 miles)."
"The better resolution of the new map helps interpret how the crust of the planet changed over Mars' history in many regions."
The study has been published online in the journal Icarus.