File:Australia's Simpson Desert (MODIS).jpg

English: The deep red sands of Australia’s Simpson Desert shimmered in the winter’s sunlight on July 14, 2023, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image.

The fourth-largest desert in Australia, this iconic desert spans about 68,000 square miles (176,500 sq km) across the border of Northern Territory, South Australia and Queensland. Sometimes called the “Holy Grail of 4-wheel driving”, the vast tract of expansive desert is also famous for massive dunes, and a very dark sky that allows for spectacular starry nights. The parallel dunes can rise as high as 120 feet (37 m).

Although extremely arid—most of the desert receives only 5 inches (12.5 cm) of rain annually—parts of the desert are prone to flooding due to runoff from heavy rain events outside of the Simpson. When doused by moisture, either from rain or floods, the desert comes alive. Wildflowers bloom, plants green up and grow, and animals congregate around formerly-dry salt pans.

The Munga-Thirri-Simpson Desert National Park sits in the center of the desert, and it is the largest national park in Australia. This park encompasses and protects the famous parallel sand dunes as well as a variety of other dunal systems. It is also notable for its extensive playa lakes (salt pans), spinifex grasslands and acacia woodlands.