Topic

Hipparchus

crater on Mars

Not who you're looking for? Others named Hipparchus: 2nd century Greek astronomer, geographer and mathematician · tyrant of Athens from c. 528 BC to 514 BC · cavalry officer in ancient Greece · dialogue attributed to Plato

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Overview

Hipparchus is an impact crater in the Phaethontis quadrangle of Mars, located at 44.8° S latitude and 151.4° W longitude. It is in diameter. It was named after the ancient Greek astronomer Hipparchus in 1973. Channels There is abundant evidence that water once flowed in river valleys on Mars. Images of curved channels have been seen in images from Mars spacecraft dating back to the early seventies with the Mariner 9 orbiter. Indeed, a study published in June 2017, calculated that the volume of water needed to carve all the channels on Mars was even larger than the proposed ocean that the planet may have had. Water was probably recycled many times from the ocean to rainfall around Mars. Some of the pictures on this page show channels in Hipparchus Crater. Gallery See also List of craters on Mars

From Wikipedia (CC BY-SA 4.0).

Notable quotes

“I have composed a book on the length of the year in which I show that the tropical year contains 365 days plus a fraction of a day which is not exactly 1/4 days as the mathematicians-astronomers suppose, but which is less than 1/4 by about 1/300.”
— Hipparchus from Ptolemy, Almagest

Quotes via Wikiquote (CC BY-SA), each with its original source.

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Not who you're looking for? Others named Hipparchus: 2nd century Greek astronomer, geographer and mathematician · tyrant of Athens from c. 528 BC to 514 BC · cavalry officer in ancient Greece · dialogue attributed to Plato

Notable quotes

“I have composed a book on the length of the year in which I show that the tropical year contains 365 days plus a fraction of a day which is not exactly 1/4 days as the mathematicians-astronomers suppose, but which is less than 1/4 by about 1/300.”
— Hipparchus from Ptolemy, Almagest

Quotes via Wikiquote (CC BY-SA), each with its original source.

Overview

Hipparchus is an impact crater in the Phaethontis quadrangle of Mars, located at 44.8° S latitude and 151.4° W longitude. It is in diameter. It was named after the ancient Greek astronomer Hipparchus in 1973. Channels There is abundant evidence that water once flowed in river valleys on Mars. Images of curved channels have been seen in images from Mars spacecraft dating back to the early seventies with the Mariner 9 orbiter. Indeed, a study published in June 2017, calculated that the volume of water needed to carve all the channels on Mars was even larger than the proposed ocean that the planet may have had. Water was probably recycled many times from the ocean to rainfall around Mars. Some of the pictures on this page show channels in Hipparchus Crater. Gallery See also List of craters on Mars

From Wikipedia (CC BY-SA 4.0).