The dominant feature on the surface of Mars’ largest satellite, Phobos, is Stickney — a 9-kilometre-wide mega crater that spans nearly half the moon. The crater lends Phobos a physical resemblance to the planet-destroying Death Star in the film “Star Wars.” But over the decades, understanding the formation of such a massive crater has proven elusive for researchers.
Extensive systems of fossilised riverbeds have been discovered on an ancient region of the Martian surface on a northern plain called Arabia Terra, supporting the idea that the now cold and dry Red Planet had a warm and wet climate about 4 billion years ago, according to University College London-led research.
New findings using data from NASA’s Mars Reconnaissance Orbiter show that gullies on modern Mars are likely not being formed by flowing liquid water. This new evidence will allow researchers to further narrow theories about how Martian gullies form, and reveal more details about Mars’ recent geologic processes.
The geologic shape of what were once shorelines through Mars’ northern plains 3.4 billion years ago convinces scientists that two large meteorites – hitting the planet millions of years apart – triggered a pair of mega-tsunamis. These gigantic waves, likely 120 metres high, forever scarred the Martian landscape and yielded evidence of cold, salty oceans.
On the morning of Sunday, 22 May planet Mars reached opposition in the constellation of Scorpius and is closest to the Earth on 30 May — its best showing in a decade for Southern Hemisphere observers. As seen from the UK the Red Planet will be low in the south at 1am BST, but on nights of good seeing surface detail will be visible in amateur telescopes. Use our interactive Mars Mapper to identify its features.
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