In Greek mythology, Nereus (/ˈnɪəriəs, ˈnɪərjuːs/; Greek: Νηρεύς) was the eldest son of Pontus (the Sea) and Gaia (the Earth), who with Doris fathered the Nereids and Nerites, with whom Nereus lived in the Aegean Sea.
R. S. P. Beekes suggests a Pre-Greek origin.
In the Iliad the Old Man of the Sea is the father of Nereids, though Nereus is not directly named. He was never more manifestly the Old Man of the Sea than when he was described, like Proteus, as a shapeshifter with the power of prophecy, who would aid heroes such as Heracles who managed to catch him even as he changed shapes. Nereus and Proteus (the "first") seem to be two manifestations of the god of the sea who was supplanted by Poseidon when Zeus overthrew Cronus.
The earliest poet to link Nereus with the labours of Heracles was Pherekydes, according to a scholion on Apollonius of Rhodes.
During the course of the 5th century BC, Nereus was gradually replaced by Triton, who does not appear in Homer, in the imagery of the struggle between Heracles and the sea-god who had to be restrained in order to deliver his information that was employed by the vase-painters, independent of any literary testimony.
Nereus is a small impact crater lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars with a diameter of about 10 metres (33 ft). It is located just south of the planet's equator on the relatively smooth Meridiani Planum (plain).
It was discovered by the Opportunity Mars rover on Sol 2010 (2009-09-19), being noticed because it is surrounded by jagged rocks, and was the Astronomy Picture of the Day for 2009-10-19.
It is named for Nereus a Greek god who lived with the Nereids in the Aegean Sea.
Nereus was a hybrid unmanned autonomous underwater vehicle (HROV, a type of remotely operated underwater vehicle) built by the Woods Hole Oceanographic Institution (WHOI). Constructed as a research vehicle to operate at depths of up to 11,000 metres (36,000 ft), it was designed to explore Challenger Deep, the deepest surveyed point in the global ocean. Nereus, named for Greek sea titan Nereus (who has a man's torso and a fish-tail) through a nationwide contest of high school and college students, began its deep sea voyage to Challenger Deep in May 2009 and reached the bottom on May 31, 2009.
On this dive the Nereus reached a depth of 35,768 feet (10,902 m), making the Nereus the world's second-deepest-diving vehicle in operation at the time, and the first since 1998 to explore the Mariana Trench, the deepest part of the ocean known.
On 10 May 2014, Nereus was lost while exploring the Kermadec Trench at a depth of 9,900 metres (32,500 ft). Communications were cut off at around 2 p.m. local time, and debris retrieved later revealed that it imploded due to high pressure.
From underwater the bubbles rise
Each one a whisper of my muffled cries
Gravity's chains break at these depths
In the palm of the tide, away I'm swept
I don't fit the mold
Instead the mold fits me
Deforming to lie then exploit
Its fingers drag, drowning aspirations
Using maturity to mask the void
That spreads like oil, diluting, polluting
In solitude I sink further from morality
Facing the deluge, picked clean of identity
Character dissolves just like the flesh
Incessantly fading, I subsist like the rest
Iridescent adolescence
Now hopelessly stark
A barnacle on a boulder
For the tempest to lark
Echoes remind me of who I'm meant to be