Giacomo F. Maraldi
Encyclopedia
Giacomo Filippo Maraldi (August 21, 1665 – December 1, 1729) was an French
-Italian
astronomer
and mathematician
. His name is also given as Jacques Philippe Maraldi.
Born in Perinaldo
(modern Liguria
) he was the nephew of Giovanni Cassini
, and worked most of his life at the Paris Observatory
(1687 – 1718). He also is the uncle of Jean-Dominique Maraldi.
From 1700 until 1718 he worked on a catalog of fixed star
s, and from 1672 until 1719 he studied Mars
extensively.
His most famous astronomical discovery was that the ice caps on Mars are not exactly on the rotational poles of that body. He also recognized that the corona
visible during a solar eclipse
belongs to the Sun
not to the Moon
, and he discovered R Hydrae
as a variable star
.
He also helped with the survey based on the Paris Meridian
.
He is also credited for the first observation (1723) of what is usually referred to as Poisson's spot, an observation that was unrecognized until its rediscovery in the early 19th century by Dominique Arago. At the time of Arago's discovery, Poisson's spot gave convincing evidence for the contested wave nature of light.
In mathematics
he is most known for obtaining the angle
in the rhombic dodecahedron
shape in 1712, which is still called Maraldi angle.
Crater
s on the Moon and Mars were named in his and his nephew's honor.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
-Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
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...
and mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
. His name is also given as Jacques Philippe Maraldi.
Born in Perinaldo
Perinaldo
Perinaldo is a comune in the Province of Imperia in the Italian region Liguria, located about 120 km southwest of Genoa and about 30 km west of Imperia....
(modern Liguria
Liguria
Liguria is a coastal region of north-western Italy, the third smallest of the Italian regions. Its capital is Genoa. It is a popular region with tourists for its beautiful beaches, picturesque little towns, and good food.-Geography:...
) he was the nephew of Giovanni Cassini
Giovanni Domenico Cassini
This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer...
, and worked most of his life at the Paris Observatory
Paris Observatory
The Paris Observatory is the foremost astronomical observatory of France, and one of the largest astronomical centres in the world...
(1687 – 1718). He also is the uncle of Jean-Dominique Maraldi.
From 1700 until 1718 he worked on a catalog of fixed star
Fixed star
The fixed stars are celestial objects that do not seem to move in relation to the other stars of the night sky. Hence, a fixed star is any star except for the Sun. A nebula or other starlike object may also be called a fixed star. People in many cultures have imagined that the stars form pictures...
s, and from 1672 until 1719 he studied 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...
extensively.
His most famous astronomical discovery was that the ice caps on Mars are not exactly on the rotational poles of that body. He also recognized that the corona
Corona
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...
visible during a solar eclipse
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
belongs to the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
not to the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, and he discovered R Hydrae
R Hydrae
R Hydrae is a Mira-type variable star in the constellation Hydra.The magnitude of R Hydrae varies over a period of 389 days, between 3.21 and 11.00. The period of R Hydrae changes slowly....
as a variable star
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
.
He also helped with the survey based on the Paris Meridian
Paris Meridian
The Paris Meridian is a meridian line running through the Paris Observatory in Paris, France—now longitude 2°20′14.025″ east. It was a long-standing rival to Greenwich as the prime meridian of the world, as was the Meridian of Antwerp in Antwerp, Belgium....
.
He is also credited for the first observation (1723) of what is usually referred to as Poisson's spot, an observation that was unrecognized until its rediscovery in the early 19th century by Dominique Arago. At the time of Arago's discovery, Poisson's spot gave convincing evidence for the contested wave nature of light.
In mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
he is most known for obtaining the angle
Angle
In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...
in the rhombic dodecahedron
Rhombic dodecahedron
In geometry, the rhombic dodecahedron is a convex polyhedron with 12 rhombic faces. It is an Archimedean dual solid, or a Catalan solid. Its dual is the cuboctahedron.-Properties:...
shape in 1712, which is still called Maraldi angle.
Crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
s on the Moon and Mars were named in his and his nephew's honor.