Sinus Meridiani
Encyclopedia
Sinus Meridiani is a feature name for an albedo feature
on Mars
stretching east-west just south of that planet's equator
. It was named by the French astronomer
Camille Flammarion
in the late 1870s.
on Mars by the French astronomer
Camille Flammarion
in the late 1870s. Prior astronomers, notably the German team of Wilhelm Beer and Johann Heinrich Mädler and then the Italian Giovanni Schiaparelli
, had chosen a particular point on Mars as being the location of its prime meridian
when they charted their observations. Accepting suggestions that dark areas on the surface of Mars were seas or oceans, Flammarion named a dark area at that point "Sinus Meridiani", literally "Meridian Bay", when he worked on his compilation and analysis of all prior observations of Mars.
Since flyby and orbital spacecraft imagery of Mars began to become available in the 1960s, dark-light albedo features on the planet have seen shifting of names to reflect the true nature of the topography, and Sinus Meridiani consequently was given a new designation, Terra Meridiani ("Meridian Land"). . However, the older and the newer designations are both in current use. The U.S. Geological Survey considers the "Sinus Meridiani" nomenclature canonical
("Meridian Plain") is used to refer specifically to the landing site of Mars Exploration Rover
Opportunity
, in the western portion of Sinus Meridiani. This site was chosen by the Mars Exploration Rover team both for its characteristic as a flat and mostly rock-free plain (and hence a safe landing site), and also as a site which showed the spectral signature of the mineral hematite
, which is often a sign of deposition in an aqueous environment.
Albedo feature
An albedo feature is a large area on the surface of a planet which shows a contrast in brightness or darkness with adjacent areas....
on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
stretching east-west just south of that planet's equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
. It was named by the French astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
Camille Flammarion
Camille Flammarion
Nicolas Camille Flammarion was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction novels, and several works about Spiritism and related topics. He also published the magazine...
in the late 1870s.
Observational History
The name Sinus Meridiani was given to the a classic albedo featureAlbedo feature
An albedo feature is a large area on the surface of a planet which shows a contrast in brightness or darkness with adjacent areas....
on Mars by the French astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
Camille Flammarion
Camille Flammarion
Nicolas Camille Flammarion was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction novels, and several works about Spiritism and related topics. He also published the magazine...
in the late 1870s. Prior astronomers, notably the German team of Wilhelm Beer and Johann Heinrich Mädler and then the Italian Giovanni Schiaparelli
Giovanni Schiaparelli
Giovanni Virginio Schiaparelli was an Italian astronomer and science historian. He studied at the University of Turin and Berlin Observatory. In 1859-1860 he worked in Pulkovo Observatory and then worked for over forty years at Brera Observatory...
, had chosen a particular point on Mars as being the location of its prime meridian
Prime Meridian
The Prime Meridian is the meridian at which the longitude is defined to be 0°.The Prime Meridian and its opposite the 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern and Western Hemispheres.An international...
when they charted their observations. Accepting suggestions that dark areas on the surface of Mars were seas or oceans, Flammarion named a dark area at that point "Sinus Meridiani", literally "Meridian Bay", when he worked on his compilation and analysis of all prior observations of Mars.
Since flyby and orbital spacecraft imagery of Mars began to become available in the 1960s, dark-light albedo features on the planet have seen shifting of names to reflect the true nature of the topography, and Sinus Meridiani consequently was given a new designation, Terra Meridiani ("Meridian Land"). . However, the older and the newer designations are both in current use. The U.S. Geological Survey considers the "Sinus Meridiani" nomenclature canonical
Meridiani Planum
The name Meridiani PlanumMeridiani Planum
Meridiani Planum is a plain located 2 degrees south of Mars' equator , in the westernmost portion of Terra Meridiani. It hosts a rare occurrence of gray crystalline hematite...
("Meridian Plain") is used to refer specifically to the landing site of Mars Exploration Rover
Mars Exploration Rover
NASA's Mars Exploration Rover Mission is an ongoing robotic space mission involving two rovers, Spirit and Opportunity, exploring the planet Mars...
Opportunity
Opportunity rover
Opportunity, MER-B , is a robotic rover on the planet Mars, active since 2004. It is the remaining rover in NASA's ongoing Mars Exploration Rover Mission...
, in the western portion of Sinus Meridiani. This site was chosen by the Mars Exploration Rover team both for its characteristic as a flat and mostly rock-free plain (and hence a safe landing site), and also as a site which showed the spectral signature of the mineral hematite
Hematite
Hematite, also spelled as haematite, is the mineral form of iron oxide , one of several iron oxides. Hematite crystallizes in the rhombohedral system, and it has the same crystal structure as ilmenite and corundum...
, which is often a sign of deposition in an aqueous environment.
External links
- Google Mars scrollable map - centered on Terra meridiani
- Planetary Science Research Discoveries: Gray Iron Oxide in Meridiani, Mars