Pharos is a crater on

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

's moon

Proteus In Greek mythology, Proteus (; Ancient Greek: Πρωτεύς, ''Prōteus'') is an early prophetic sea-god or god of rivers and oceanic bodies of water, one of several deities whom Homer calls the "Old Man of the Sea" ''(hálios gérôn)''. ...

. It is named after the

Lighthouse of Alexandria The Lighthouse of Alexandria, sometimes called the Pharos of Alexandria (; Ancient Greek: ὁ Φάρος τῆς Ἀλεξανδρείας, contemporary Koine ), was a lighthouse built by the Ptolemaic Kingdom of Ancient Egypt, during the rei ...

, also known as the Pharos of Alexandria. It is currently the only named surface feature on any irregularly shaped

moon of Neptune The planet Neptune has 14 known moons, which are named for minor water deities in Greek mythology. By far the largest of them is Triton, discovered by William Lassell on October 10, 1846, 17 days after the discovery of Neptune itself; over a ce ...

. It measures 10–15 km deep and has a diameter of around in diameter, making it more than half the diameter of Proteus itself. The impact that created Pharos may have also created

Hippocamp The hippocampus or hippocamp, also ''hippokampos'' (plural: hippocampi or hippocamps; grc, ἱππόκαμπος, from , "horse" and , "sea monster"

, due to how unusually close it is to Proteus.

References

Surface features of Neptune's moons Proteus (moon) Lighthouse of Alexandria {{Astronomy-stub