Why is Hellas Planitia the oldest surface on Mars?

Topographic map of Hellas Planitia and its surroundings in the southern uplands, from the MOLA instrument of Mars Global Surveyor….Hellas Planitia.

Viking orbiter image mosaic of Hellas Planitia
Planet	Mars
Region	Hellas quadrangle, south of Iapygia
Coordinates	42.4°S 70.5°ECoordinates:42.4°S 70.5°E
Quadrangle	Hellas quadrangle

Where is Hellas Planitia located on Mars?

Mars southern hemisphere
Hellas Planitia is a vast meteorite impact basin located at 42° 42’S 70° 00’E, in the Mars southern hemisphere.

What’s the biggest crater on Mars?

Hellas Impact Crater
Hellas Impact Crater (also known as Hellas Planitia) is an enormous impact crater in the southern hemisphere of Mars. It is about 2,300 kilometers (1,400 miles) in diameter and about 9 kilometers (5 miles) deep. It is the largest impact crater on the planet.

Is Hellas Planitia a crater?

With a diameter of about 1,400 miles and a depth reaching the lowest elevations on Mars, Hellas is one of the largest impact craters in the solar system. The area has a number of unusual features, which are thought to be quite old because of the high crater density.

What is Hellas Planitia and how did it form?

A color image of the Hellas Planitia region of Mars; north toward top. The scene shows the Hellas plain within the 1,800- km-diameter Hellas basin, an ancient impact basin (and the largest basin on Mars) formed when a large projectile (asteroid, comet, meteor) hit the surface.

How deep is the Hellas basin?

7 km
Scarring the southern highlands of Mars is one of the Solar System’s largest impact basins: Hellas, with a diameter of 2300 km and a depth of over 7 km.

How big is the Hellas basin?

about 7,000 km
Hellas, enormous impact basin in the southern hemisphere of Mars and the planet’s largest recognizable impact feature. Centred at roughly 40° S, 290° W, Hellas measures about 7,000 km (4,400 miles) across, including the broad elevated ring surrounding the depression, and 8 km (5 miles) deep.