Dune (crater)

Dune is a feature on Earth's Moon, a crater in the Hadley–Apennine region. Astronauts David Scott and James Irwin visited the south rim of it in 1971, on the Apollo 15 mission, during EVA 2. The south rim of Dune was designated Geology Station 4 of the mission.

Dune is located about 1.8 km east of Hadley Rille, less than 1 km south of the smaller Earthlight crater, and about 3 km south of the Apollo 15 landing site itself.

The crater was named by the astronauts after the novel by Frank Herbert, and the name was formally adopted by the IAU in 1973.

Samples

The following samples were collected from Dune Crater (Station 4), as listed in Table 5-II of the Apollo 15 Preliminary Science Report. Sample type, lithology, and description are from Table 5-IV of the same volume.

Samples 15470 to 15476 were collected near where the rover was parked to the south of the rim of Dune. Samples 15485, 15486, and 15499 were collected from the largest boulder in the photograph above. Sample 15498 was collected nearby.

Dune

In physical geography, a dune is a hill of sand built by either wind or water flow. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a slack. A "dune field" is an area covered by extensive sand dunes.

Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds.

Dunes can form under the action of water flow (fluvial processes), and on sand or gravel beds of rivers, estuaries and the sea-bed.

The modern word "dune" came into English from French circa 1790.

Arrakis

Arrakis (/əˈrækᵻs/;Arabic: الراقص‎, ar-rāqiṣ, "the dancer") — informally known as Dune and later called Rakis — is a fictional desert planet featured in the Dune series of novels by Frank Herbert. Herbert's first novel in the series, 1965's Dune, is popularly considered one of the greatest science fiction novels of all time, and it is sometimes cited as the best-selling science fiction novel in history.

In Dune, the planet is the home of the Fremen (Zensunni wanderers), and subsequently is the Imperial Capital of the Atreides Empire. Arrakis is the third planet orbiting the star Canopus, and it in turn is orbited by two moons, one of which has the image of the desert kangaroo mouse, Muad'Dib, on it; the other moon possesses the image of a human hand.

Environment and the spice

A desert planet with no natural precipitation, in Dune it is established that Arrakis had been "His Imperial Majesty's Desert Botanical Testing Station" before the discovery of melange, for which it is the only natural source in the universe. Melange (or, "the spice") is the most essential and valuable commodity in the universe, as it extends life and makes safe interstellar travel possible (among other uses). The planet has no surface water bodies, but open canals called qanats are used "for carrying irrigation water under controlled conditions" through the desert. The Fremen collect water in underground reservoirs to fulfill their dream of someday terraforming the planet, and pay the Spacing Guild exorbitant fees in melange to keep the skies over Arrakis free of any satellites which might observe their efforts. As indicated by its large salt flats, Arrakis once had lakes and oceans; Lady Jessica also notes in Dune that wells drilled in the sinks and basins initially produce a "trickle" of water which soon stops, as if "something plugs it."

Dune (disambiguation)

A dune is a hill of sand.

Dune or dunes may also refer to:

Arts and entertainment

Science fiction

Music

Bands and musicians

Albums

Crater

Crater may refer to:

In landforms:

Other:

Crater (Aden)

Crater (/ˈkreɪtər/; Arabic: كريتر‎, [ˈkɾeːtəɾ]), also Kraytar, is a district of the Aden Governorate, Yemen. Its official name is Seera (Arabic: صيرة Ṣīrah). It is situated in a crater of an ancient volcano which forms the Shamsan Mountains. In 1991, the population was 70,319. As of 2003, the district had a population of 76,723 people.

In the closing days of British rule in 1967, Crater District became the focus of the Aden Emergency, sometimes called the last imperial war. After a mutiny of hundreds of soldiers in the South Arabian Federation Army on 20 June, all British forces withdrew from the Crater. The Crater was occupied by Arab fighters while British forces blocked off its two main entrances. In July, a British infantry battalion, led by Lt. Col. Colin Mitchell of the Argyll & Sutherland Highlanders, entered the Crater and managed to occupy the entire district overnight with no casualties. Nevertheless, deadly guerrilla attacks soon resumed, with the British leaving Aden by the end of November 1967, earlier than had been planned by British Prime Minister Harold Wilson and without an agreement on the succeeding governance.

Crater (constellation)

Crater is a constellation. Its name is Latin for cup, and in Greek mythology it is identified with the cup of the god Apollo. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is faint, with no star brighter than third magnitude.

Notable features

Stars

Alpha Crateris, traditionally called Alkes, is an orange-hued giant star of magnitude 4.1, 174 light-years from Earth. Its traditional name means "the cup". Beta Crateris is a blue-white hued star of magnitude 4.5, 266 light-years from Earth. Gamma Crateris is a double star divisible in small amateur telescopes. The primary is a white star of magnitude 4.1, 84 light-years from Earth. The secondary is of magnitude 9.6. Delta Crateris is the brightest star in Crater at magnitude 3.6. 195 light-years away, it is an orange-hued giant star.

R Crateris is a semi-regular variable of type SRb and a spectral classification of M7. It has a magnitude of 9.8-11.2 and an optical period of 160 days.