|Dimensions||530×407×370 ±7 km
431 km (mean)
|Surface area||837,080.744 km2 (323,198.682 sq mi)|
|Mass||(8.67 ±0.15)×1019 kg|
|Mean density||2.08 ± 0.10 g/cm³|
|Equatorial surface gravity||0.091 m/s²|
|Escape velocity||0.21 km/s|
|Rotation period||27.623 h (1.15 d)|
max: 247 K (−26°C) 
Union Celestial Object (Asteroid) in the Sol System.
Occupied and utilized since 2198 -
Main settlement Gasparis Viillage -
Population : 2400
Not represented on its own but belongs to the Asteroid Belt Association.
It was once a prime source for Olivine and was mined for that mineral. Now it is a Research Clinic complex treating and researching Neural diseases and psycho conditions.
Access is limited and there is no trade
10 Hygiea is the fourth largest asteroid in the Solar System by volume and mass and is located in the asteroid belt. With somewhat oblong diameters of 350–500 km, and a mass estimated to be 2.9% of the total mass of the belt, it is the largest of the class of dark C-type asteroids with a carbonaceous surface.
Despite its size, it appears very dim when observed from Earth. This is due to its dark surface and larger-than-average distance from the Sun. For this reason, several smaller asteroids were observed before Annibale de Gasparis discovered Hygiea on April 12, 1849.
Hygiea's surface is composed of primitive carbonaceous material with a spectrum similar to those of carbonaceous chondrite meteorites. Aqueous alteration products have been detected on its surface,
It is the main member of the Hygiea family and contains almost all the mass in this family (well over 90%). It is the largest of the class of dark C-type asteroids that are dominant in the outer asteroid belt—which lie beyond the Kirkwood gap at 2.82 AU. Hygiea has a noticeably oblate spheroid shape, with an average diameter of 444 ± 35 km and a semimajor axis ratio of 1.11. This is much more than for the other objects in the "big four"—2 Pallas, 4 Vesta and the dwarf planet Ceres. Aside from being the smallest of the four, Hygiea, like Ceres, has a relatively low density, which is more comparable to the icy satellites of Jupiter or Saturn than to the terrestrial planets or the stony asteroids.