Umbriel (um'-bree-əl, IPA /ˈɐmbriəl/) is a moon of Uranus discovered on 1851-10-24 by William Lassell. It was discovered at the same time as Ariel. Original Caption Released with Image: The southern hemisphere of Umbriel displays heavy cratering in this Voyager 2 image, taken Jan. ... William Lassell (June 18, 1799 – October 5, 1880) was a British astronomer, born in Bolton, Greater Manchester, England. ... October 24 is the 297th day of the year (298th in leap years) in the Gregorian Calendar, with 68 days remaining. ... 1851 was a common year starting on Wednesday (see link for calendar). ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... The semi-major axis of an ellipse In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolas. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... The circumference is the distance around a closed curve. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... Speed (symbol: v) is the rate of motion, or equivalently the rate of change of position, expressed as distance d moved per unit of time t. ... Speed (symbol: v) is the rate of motion, or equivalently the rate of change of position, expressed as distance d moved per unit of time t. ... Speed (symbol: v) is the rate of motion, or equivalently the rate of change of position, expressed as distance d moved per unit of time t. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... Moons of solar system scaled to Earths Moon The common noun moon (not capitalized) is used to mean any natural satellite of the other planets. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... For the geometric term, see diameter. ... -1... Square kilometre (US spelling: Square kilometer), symbol km², is an SI unit of surface area. ... Volume, also called capacity, is a quantification of how much space an object occupies. ... A cubic kilometre (symbol km³) is an SI derived unit of volume. ... Mass is a property of a physical object that quantifies the amount of matter it contains. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... It has been suggested that gravitation be merged into this article or section. ... Acceleration is the time rate of change of velocity, and at any point on a v-t graph, it is given by the gradient of the tangent to that point In physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. ... In physics, for a given gravitational field and a given position, the escape velocity is the minimum speed an object without propulsion, at that position, needs to have to move away indefinitely from the source of the field, as opposed to falling back or staying in an orbit within a... On a prograde planet like the Earth, the sidereal day is shorter than the solar day. ... Axial tilt is an astronomical term regarding the inclination angle of a planets rotational axis in relation to its orbital plane. ... The albedo is a measure of reflectivity of a surface or body. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... diurnal (daily) rhythm of air pressure in northern Germany (black curve is air pressure) Atmospheric pressure is the pressure above any area in the Earths atmosphere caused by the weight of air. ... The pascal (symbol Pa) is the SI unit of pressure. ... IPA may refer to: The International Phonetic Alphabet or India Pale Ale ... Moons of solar system scaled to Earths Moon The common noun moon (not capitalized) is used to mean any natural satellite of the other planets. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... 1851 was a common year starting on Wednesday (see link for calendar). ... October 24 is the 297th day of the year (298th in leap years) in the Gregorian Calendar, with 68 days remaining. ... William Lassell (June 18, 1799 – October 5, 1880) was a British astronomer, born in Bolton, Greater Manchester, England. ... Atmospheric pressure 0 kPa Ariel (air-ee-ul, pronounced ) is a moon of Uranus discovered on 1851-10-24 by William Lassell. ...

Name

The name "Umbriel" and the names of all four satellites of Uranus then known were suggested by John Herschel in 1852 at the request of Lassell ([2]). Lassell had earlier endorsed Herschel's 1847 naming scheme for the seven then-known satellites of Saturn and had named his newly-discovered eighth satellite Hyperion in accordance with Herschel's naming scheme in 1848. Umbriel is the 'dusky melancholy sprite' in Alexander Pope's The Rape of the Lock, and the name suggests the Latin umbra, shadow. It is also designated Uranus II. John Herschel Sir John Frederick William Herschel (7 March 1792 – 11 May 1871) was an English mathematician and astronomer. ... 1847 was a common year starting on Friday (see link for calendar). ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Hyperion (hye-peer-ee-un, Greek ‘Υπερίων) is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. ... 1848 is a leap year starting on Saturday of the Gregorian calendar. ... Alexander Pope, an English poet best known for his Essay on Criticism and Rape of the Lock Pope, circa 1727. ... The Rape of the Lock is a mock-heroic poem written by Alexander Pope, first published in 1712 in two cantos, and then reissued in 1714 in a much-expanded 5-canto version. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... A different sense of the word umbra, used in mathematics, is explained in the article titled umbral calculus. ...

Physical characteristics

So far the only close-up images of Umbriel are from the Voyager 2 probe, which made observations of the moon during its Uranus flyby in January, 1986. During the flyby the southern hemisphere of the moon was pointed towards the Sun so only it was studied. The Voyager 2 spacecraft was launched in 1977. ... The Sun is the star at the center of our Solar system. ...

Umbriel's surface is the darkest of the Uranian moons, and it is also the least geologically active. It is mostly composed of water ice, with the balance made up of silicate rock, and probably other ices such as carbon dioxide and/or methane. In chemistry, a silicate is a compound consisting of silicon and oxygen (SixOy), one or more metals, and possibly hydrogen. ... R-phrases S-phrases , , , Flash point −188 °C Autoignition temperature 537 °C Explosive limits 5–15% Supplementary data page Structure and properties Thermodynamic data Spectral data UV, IR, NMR, MS Related compounds Related alkanes Ethane Propane Related compounds Methanol Chloromethane Except where noted otherwise, data are given for materials in...

Umbriel's most prominent feature is Wunda, a large ring of bright material near Umbriel's equator (see picture; the viewpoint is nearly polar). Wunda is presumably some kind of crater, but its exact nature is mysterious. Nearby, seen along the terminator, is the crater Skynd, which lacks a bright rim but possesses a bright central peak. Wunda is a large ring of bright material on the surface of Uranuss moon Umbriel. ... Tycho crater on Earths moon. ...

Umbriel in fiction

• In the video game Fire Emblem, Umbriel is the name of the character Vaida's wyvern mount.
• In the manga Ansatsu, one of the key antagonists of the story is named Umbriel.

A computer game is a game composed of a computer-controlled virtual universe that players interact with in order to achieve a defined goal or set of goals. ... Eliwood, Hector and Lyn (from Fire Emblem: Blazing Sword, the first Fire Emblem to be released internationally). ... Listen to this article · (info) This audio file was created from an article revision dated 2005-08-27, and does not reflect subsequent edits to the article. ... A page from the Marmalade Boy manga, volume 1 (Japanese version) Manga (漫画) is the Japanese word for comics and print cartoons; outside of Japan, it usually refers specifically to Japanese comics. ... Ansatsu (translated roughly into English as The Assassination) is a currently amateur manga by PsychoSwordLady. ... This article refers to literary antagonists. ... Ansatsu (translated roughly into English as The Assassination) is a currently amateur manga by PsychoSwordLady. ...

See also

• List of craters on Umbriel

This is a list of named craters on Umbriel. ...

External links

• William Lassell, Astronomical Journal 2 (1851) 70
• AN, 33 (1852) 257/258
• AN, 34 (1852) 325/326
• Voyager 2 images of Umbriel

Uranus (satellites) edit
Cordelia | Ophelia | Bianca | Cressida | Desdemona | Juliet | Portia | Rosalind | Cupid
Belinda | Perdita | Puck | Mab | Miranda | Ariel | Umbriel | Titania | Oberon | Francisco
Caliban | Stephano | Trinculo | Sycorax | Margaret | Prospero | Setebos | Ferdinand
See also: Pronunciation key | Rings of Uranus