What is Proteus?
Q: What is Proteus?
A: Proteus or Neptune VIII is the second biggest moon of Neptune, and its biggest close moon. It is named after Proteus, the shape-changing sea god of Greek mythology.
Q: How was Proteus discovered?
A: Proteus was found from the images taken by Voyager 2 probe during the Neptune flyby in 1989. It got the designation S/1989 N 1. Stephen P. Synnott and Bradford A. Smith said (IAUC 4806) its discovery on July 7, 1989, speaking only of “17 frames taken over 21 days”, which gives a discovery date of sometime before June 16. The name was given on 16 September 1991.
Q: Why wasn't it seen by Earth-based telescopes?
A: Proteus was not seen by Earth-based telescopes because it is so close to the planet that it is lost in the glare of reflected sunlight.
Q: How reflective is Proteus?
A: Proteus reflects only 6 percent of the sunlight that hits it - one of the darkest objects in the solar system like Saturn's moon Phoebe.
Q: Is there any sign of geological changes on Proteus?
A: No, there is no sign of any geological changes on Proteus - it is very cratered with no evidence for any activity or change over time.
Q: What shape does Proteus have?
A: Scientists believe that despite being less massive than other moons such as Mimas, due to its density, it has not been pulled into a spherical shape by its own gravity and instead remains an irregular shape unlike Mimas' more spherical form.
