Rub' al Khali in the context of "Arabian Desert"

A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location.

Deserts are formed by weathering processes as large variations in temperature between day and night strain the rocks, which consequently break into pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting fragments and rubble strewn over the desert floor are further eroded by the wind. This picks up particles of sand and dust, which can remain airborne for extended periods – sometimes causing the formation of sand storms or dust storms. Wind-blown sand grains striking any solid object in their path can abrade the surface. Rocks are smoothed down, and the wind sorts sand into uniform deposits. The grains end up as level sheets of sand or are piled high in billowing dunes. Other deserts are flat, stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones, often forming desert pavements, and little further erosion occurs. Other desert features include rock outcrops, exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate. There may be underground water sources in the form of springs and seepages from aquifers. Where these are found, oases can occur.

An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The word is derived from the Arabic word ʿirq (عرق), meaning 'dune field'. Strictly speaking, an erg is defined as a desert area that contains more than 125 km (48 sq mi) of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers 9 million square kilometres (3.5×10^ sq mi) and contains several ergs, such as the Chech Erg and the Issaouane Erg in Algeria. Approximately 85% of all the Earth's mobile sand is found in ergs that are greater than 32,000 km (12,355 sq mi), the largest being the Rub' al Khali, the Empty Quarter of the Arabian Peninsula. Ergs are also found on other celestial bodies, such as Venus, Mars, and Saturn's moon Titan.

Najd is a historical region of the Arabian Peninsula that includes most of the central region of Saudi Arabia. It is roughly bounded by the Hejaz region to the west, the Nafud desert in al-Jawf to the north, ad-Dahna Desert in al-Ahsa to the east, and Rub' al-Khali to the south, although its exact boundaries cannot be determined due to varying geographical and political limits throughout history.

Administratively, Najd is divided into three main regions: the Riyadh region which features Wadi Hanifa and the Tuwaiq escarpment, which houses easterly Yamama with the Saudi capital, Riyadh since 1824, and the Sudairi region, which has its capital in Majmaah. The second region, Al-Qassim, houses the fertile oases and date palm orchards spread out in the region's highlands along Wadi Rummah in central Najd with its capital in Buraidah, the second largest Najdi city, with the region historically contested by the House of Rashid to its north and the House of Saud to its east and south. The third administrative unit is northerly Ḥa'il, which features the mountains of Jabal Shammar housing the Tayy capital of Ḥa'il.

The Nafud desert or simply The Nafud (Arabic: صحراء النفود, romanized: ṣahrā' an-nafūd) is a desert in the northern part of the Arabian Peninsula at 28°18′N 41°00′E / 28.30°N 41.00°E / 28.30; 41.00, occupying a great oval depression. It is 290 kilometres (180 mi) long and 225 kilometres (140 mi) wide, with an area of 65,000 square kilometres (25,000 sq mi).

The Nafud is an erg, a desert region located in north-central Saudi Arabia. It is noted for its sudden violent winds, which account for the large crescent-shaped dunes. The sand in the Nafud is a brick-reddish color. Rain comes once or twice per year. In some lowland areas, namely those near the Hejaz Mountains, there are oases where dates, vegetables, barley, and fruits are grown. The Nafud is connected to the Rub' al Khali by the Dahna, a corridor of gravel plains and sand dunes, 800 mi (1,287 km) long and 15 to 50 miles (24.1 to 80.5 km) wide.

The Imamate of Oman (Arabic: إِمَامَة عُمَان, romanised: Imāmat ʿUmān) was several succession of states within the Oman proper (Arabic: عُمَان ٱلْوُسْطَى, romanised: ʿUmān al-Wusṭā, lit. 'Central Oman') in the Hajar Mountains, part of the present-day Sultanate of Oman. The capital of the Imamate alternated historically between Rustaq and Nizwa. The Imamate's territory extended north to Ibri and south to the Alsharqiyah region and the Sharqiya Sands. The Imamate was bounded in the east by the Hajar Mountains and in the west by the Rub' al Khali (Empty Quarter) desert. The Al Hajar Mountains separated the Imamate of Oman from Muscat and Oman. The elected Imam (ruler) resided in the capital, and Walis (governors) represented the Imamate in its different regions.

The Imamate of Oman, similar to the Sultanate of Muscat, was ruled by the Ibadi sect. Imams exercised spiritual and temporal representation over the region. The Imamate is a 1,200-year-old system of government pioneered by the Ibadi religious leaders of Oman, and was based upon the Islamic sharia. The Imamate holds that the ruler should be elected. The imam is considered as the head of the community but tribalism that is part of the Omani society encouraged a decentralised form of governance that would help sustain political unity among the Omanis. The Imamate set out a government system wherein the ruler should not have absolute political nor military power; rather power should be shared with local governors. To prevent local or external threats to the Imamate, the imam had to gather the support of the local communities and tribes to raise a force to fight for a certain cause. The imam needed in-depth understanding of tribal politics and political acumen to maintain political stability within the Imamate when conflicts occurred.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a Japanese remote sensing instrument onboard the Terra satellite launched by NASA in 1999. It has been collecting data since February 2000.

ASTER provides high-resolution images of Earth in 14 different bands of the electromagnetic spectrum, ranging from visible to thermal infrared light. The resolution of images ranges between 15 and 90 meters. ASTER data is used to create detailed maps of surface temperature of land, emissivity, reflectance, and elevation.

The sand cat (Felis margarita) is a small wild cat that inhabits sandy and stony deserts far from water sources. With its sandy to light grey fur, it is well camouflaged in a desert environment. Its head-and-body length ranges from 39–52 cm (15–20 in) with a 23–31 cm (9.1–12.2 in) long tail. Its 5–7 cm (2.0–2.8 in) short ears are set low on the sides of the head, aiding detection of prey moving underground. The long hair covering the soles of its paws insulates its pads against the extreme temperatures found in deserts.

The first sand cat known to scientists was discovered in the Algerian Sahara and described in 1858. To date, it has been recorded in several disjunct locations in Western Sahara, Morocco, Algeria, Niger, Chad, Egypt, the Arabian Peninsula and the Middle East. In Central Asia, it was first recorded in the Karakum Desert in 1925. The large gap between these two regions of its global range was partially closed in 1948, when a sand cat skin was found in an oasis of the Rub' al Khali in Oman. It is discontinuously distributed in the deserts of the Arabian Peninsula and the Middle East. In the early 1970s, sand cats were caught in southwestern Pakistan and exported to zoos worldwide. Due to its wide distribution and large population, it is listed as Least Concern on the IUCN Red List.