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Shedding light on Pluto’s glaciers

What is the origin of the large heart-shaped nitrogen glacier on Pluto revealed by NASA’s New Horizons spacecraft in 2015? Two French researchers show that Pluto’s peculiar insolation and atmosphere favour nitrogen condensation near the equator, in the lower altitude regions, leading to an accumulation of ice at the bottom of Sputnik Planum, a vast topographic basin.

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Mystery solved: Martian moons formed by a giant impact

Where did the two natural satellites of Mars, Phobos and Deimos, come from? For a long time, their shape suggested that they were captured asteroids. However, the shape and course of their orbits contradict this hypothesis. Two independent and complementary studies now provide an answer: these satellites formed from the debris of a gigantic collision between Mars and a protoplanet one-third its size.

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Great tilt gave ancient Mars a new face

Mars hasn’t always looked like it does today. Some 3 to 3.5 billion years ago, the planet underwent a huge tilt of 20 to 25 degrees. The gigantic Tharsis volcanic dome, which started to form over 3.7 billion years ago, grew so massive that it caused Mars’ crust and mantle to swivel around, shifting the Tharsis dome to the planet’s equator.