Hellas Planitia
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Hellas Planitia is a plain located within the huge, roughly circular impact basin Hellas located in the southern hemisphere of the planet Mars. Hellas is the fourth or fifth-largest known impact crate
Viking orbiter image mosaic of Hellas Planitia
Geographic context of Hellas
Apparent viscous flow features on the floor of Hellas, as seen by HiRISE.
Twisted bands on the floor of Hellas Planitia, as seen by HiRISE under HiWish program
Borealis Basin
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The North Polar Basin, more commonly known as the Borealis Basin, is a large basin in the northern hemisphere of Mars that covers 40% of the planet. Some scientists have postulated that the basin form
Hellas Planitia
…2,300 km (1,400 mi), it is the largest unambiguous well-exposed impact structure on the planet; the obscured Utopia Planitia is slightly larger (the Borealis Basin, if it proves to be an impact crater, is considerably larger). Hellas Planitia is thought to have been formed during the Late Heavy Bombardment period…
The moons of Mars, Phobos and Deimos. Phobos is the larger of the two moons, and is the closer of the two to Mars. Phobos has an average radius of 11 km, while Deimos has an average radius of 6 km.
Lomonosov crater, the most likely candidate for the impact that produced the tsunami. It is 150 km in diameter, and is a prominent feature of the Borealis basin.