WEBVTT FILE

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Music

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A fleet of robotic spacecraft
is exploring the Red Planet,

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and scientists are finding new
ways to mine an ever-growing
mountain of data.

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Satellites always orbit a
planet's center of mass,

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but they can be pulled slightly
off course by the gravity of
massive

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features like Olympus  Mons, the
solar system's tallest peak. 

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Now, a team of scientists at
NASA's Goddard Space Flight
Center

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has used small fluctuations
in the orbital data

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of three spacecraft to map
the gravity field of Mars.

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In this new map, low-gravity
canyons like Valles Marineris,

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in blue, stand out from the
high-gravity reds and whites
of the Tharsis mountains.

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By comparing gravity with
topography, the scientists made

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an improved estimate for the
crustal thickness of Mars,

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shedding light on its geologic
history

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and confirming earlier
indications that the planet
has a molten outer core. 

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The orbital data also revealed
seasonal variations in the mass
of the polar caps,

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showing that up to four trillion
tons of carbon dioxide cycle
annually between the poles.

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The new gravity map should prove
useful to future missions as
well,

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by allowing spacecraft to
enter orbit more precisely,

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thus ensuring that the Mars
fleet continues to return
a massive trove of data.

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Music

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Satellite beeping