Tree-like dunes on Mars. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The image was taken near the North Pole of Mars, spring 2010. Objects about 25 centimetres across are resolved on this image, which is about one kilometre wide. Close ups of some parts of this image show billowing plumes indicating that the sand slides were occurring at the time of the photo; see center left.
There are three officially named dune fields on Venus. They are named after desert goddesses, as per the IAU's rules. They are listed below.
Al-Uzza Undae 67.7N, 90.5E – named after Uzza, an Arabian desert goddess
Menat Undae 24.8S, 339.4E
Ningal Undae 9.0N, 60.7E – named after Ningal, the wife of the Sumerian desert god Sin
Mars
Dunes in Abalos Undae, Mars appear blueish due to basalt, while the reddish-white areas may be dust.
There are six officially named dune fields on Mars, which are named after nearby classical albedo features in accordance with the IAU's rules. Five of them lie between 75°N to 85°N, between Planum Boreum and Vastitas Borealis. These dune fields span over 200 degrees of longitude. The sixth, Ogygis Undae, lies on the southern hemisphere of Mars. They are listed below.
Namib sand dune (downwind side) on Mars (Curiosity rover; 17 December 2015).
Bagnold dune field, Gale crater. This dune field was explored by Curiosity between initially between mission Sols ~1174–1248, where the rover investigated High dune, and Namib dune. Three orders of bedform were identified: wind ripple, large ripple (or wind drag ripple[6]) and dune.[7] Sand grains in this section of the dune field had a modal grain size of 120 μm[8]
Namib dune, Gale crater. This is a prominent feature that looks like the giant dunes of Africa’s Namib Desert.[9]
As part of the Mars Exploration Rover mission, a small dune field unofficially named El Dorado on the south side of Husband Hill in Gusev crater was investigated by the Spirit rover from sols 706 to 710.[10] Analysis of El Dorado showed that it consists of black wind-blown sand which is "well-sorted, well-rounded and olivine rich.[11]
Detail of the dunes of the Hagal Dune Field
The Hagal dune field is named after Frank Herbert's novel Dune and the fictional planet Hagal. The field is also known as the "Martian Morse Code" due to the similarity of the Dune shapes to Morse code dots and dashes.
There are five officially named dune fields on Titan, which are named after Greek gods, goddesses or personifications of wind. They are listed below:[12]
Aura Undae
Boreas Undae
Eurus Undae
Notus Undae
Zephyrus Undae
Literature also uses names of dark albedo features when referring to Titan's dune fields:
Analysis of high resolution photos from New Horizons taken on 14 July 2015 of Pluto's Sputnik Planum region in 2018 has confirmed the presence of transverse dunes (perpendicular to the wind streaks) within the cellular nitrogen plains, spaced about 0.4 to 1 km apart, that are thought to be composed of 200-300 μm diameter particles of methane ice believed to be derived from the nearby Al-Idrisi Montes.[2][3] These features are yet to be formally named.
^ abcArnold, K.; J. Radebaugh; C. J. Savage; E.P. Turtle; R.D. Lorenz; E.R. Stofan; A. Le-Gall & the Cassini Radar Team. "Areas of Sand Seas on Titan from Cassini Radar and ISS: Fensal and Aztlan"(PDF). 42nd Lunar and Planetary Science Conference, March 7–11, 2011 at The Woodlands, Texas. LPI Contribution No. 1608. Lunar and Planetary Institute. p. 2804.