Protée (the moon)

|- | bgcolor=" #000000" colspan=" 2" align=" center" |
Protée seen by Travelling 2 at the time of its passage on August 25th, 1989. Source: NASA |----- ! bgcolor=" #6295da" colspan=" 2" | Discovered |----- | Discovered by | |----- | Discovered in | 1989 |----- ! bgcolor=" #6295da" colspan=" 2" | Characteristics of the Orbit |----- | Equatorial radius | 117.647 km |----- | orbital Eccentricity | 0,0005 |----- | Period of revolution | 1,122 D |----- | Slope | 0,026° |----- | Natural satellite of | Neptune |----- ! bgcolor=" #ffc0c0" colspan=" 2" | Physical characteristics |----- | Dimensions | 436 × 416 × 402 km |----- | Mass | 5,0 × 10¹⁹ kg |----- | Density average | 1,3×10³ kg/m³ |----- | Gravity of surface | 0,075 m/s² |----- | Period of rotation | probablement
synchronous |----- | Albedo | 0,10 |----- | Temperature moyenne
on the surface | ~70 K |----- ! bgcolor=" #6295da" colspan=" 2" | Characteristics of the atmosphere |----- | Atmospheric pressure | No atmosphere |} Protée (NR VIII Proteus) is the larger second the moon of Neptune and also one of the darkest objects of the Solar system, almost as sinks as the Suie: like the majority of the moons of gas planets, it reflects only 10% of the Lumière which strikes it. He was discovered in 1989 by Stephen P. Synnott and Bradford A. Smith at the time of the passage of the probe Voyager 2 close to Neptune, it or little before the June 16th (temporary designation S/1989 NR 1 ).

Protée is a star of the irregular shape, covered with craters of impact, and does not show any sign of geological modification. It is thought that Protée is as large as it is possible for the moon to be it without becoming spherical under its own gravity.

It bears the name of Protée, a marine god of the Greek Mythologie which could change form at will, wire of Poséidon (of unknown mother).

Not to confuse with the Asteroid (9313) Protéa. Protée