Hipparchus is an
impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
in the
Phaethontis quadrangle
The Phaethontis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Phaethontis quadrangle is also referred to as MC-24 (Mars Chart-24).
The name com ...
of
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
, located at 44.8° S latitude and 151.4° W longitude. It is in diameter. It was named after the ancient Greek astronomer
Hipparchus
Hipparchus (; el, Ἵππαρχος, ''Hipparkhos''; BC) was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equi ...
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.
[Luo, W., et al. 2017. New Martian valley network volume estimate consistent with ancient ocean and warm and wet climate. Nature Communications 8. Article number: 15766 (2017). doi:10.1038/ncomms15766] Some of the pictures on this page show channels in Hipparchus Crater.
Gallery
Wikihipparchus.jpg, East side of ''Hipparchus'', as seen by CTX camera (on Mars Reconnaissance Orbiter
''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, an ...
(MRO)
Wikihipparchuschannels.jpg, Small channels in ''Hipparchus'', as seen by CTX camera on MRO (enlargement of the previous image)
ESP 046240 1360channels.jpg, Wide view of channels on rim of ''Hipparchus'', as seen by HiRISE
High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...
under HiWish HiWish is a program created by NASA so that anyone can suggest a place for the HiRISE camera on the Mars Reconnaissance Orbiter to photograph. It was started in January 2010. In the first few months of the program 3000 people signed up to use HiRIS ...
program
46240 1360channels.jpg, Close view of channels on rim of ''Hipparchus'', as seen by HiRISE under HiWish program
46240 1360channelstop.jpg, Close view of channels on rim of ''Hipparchus'', as seen by HiRISE under HiWish program
See also
*
List of craters on Mars
References
{{Geography of Mars
Phaethontis quadrangle
Impact craters on Mars