The Ar Rub’ al Khali, or Empty Quarter, covers much of the south-central portion of the Arabian Peninsula and is the largest continuous sand desert on Earth.
This astronaut photograph shows classic large and small sand masses of the central Sahara Desert, where wind is a more powerful land-shaping agent than water.
Rainfall from the remnants of Tropical Cyclone Mekunu dropped enough rain over the Arabian Peninsula to form lakes between the sand dunes in the Rub’ al-Khali.
he Issaouane Erg (sand sea) is located in eastern Algeria between the Tinrhert Plateau to the north and the Fadnoun Plateau to the south. Considered to be part of the Sahara Desert, the Issaouane Erg covers an area of approximately 38,000 km2. These complex dunes form the active southwestern border of the sand sea.
Astronauts have obtained thousands of detailed images of the world’s remote deserts, helping scientists better understand local geomorphological features in a regional context. Driven by northwesterly winds, sands from northwest Saudi Arabia have accumulated in the center of the country as great rivers of dunes (cordons) that extend for hundreds of kilometers. About 320 kilometers northwest of Riyadh, the steep, almost cliff-like margin of the Ad Dahna cordon casts a shadow (right center; diagonally across the scene). Two types of dune surface appear: the tracery of numerous linear dunes (center) and a featureless sand sheet (lower left). Dark, older rocks (30-65 million years old—top right) underlie the sand sea and crop out northeast of the cordon. Convergent dry river beds appear top right.