The giant basins seen on the Moon, Mars, and Mercury were formed during the period of heavy bombardment. This oblique view of the 900-km-diameter Argyre Basin shows the smooth floor deposits within the basin, sinuous ridges, and the mountainous nature of the rim. The bright streaks above the edge of the planet are due to hazes in the thin martian atmosphere. The Argyre Basin appears to be the youngest of the large basins seen on Mars.
Viking mosaic P17022