Ceres

Ceres is the largest object in the asteroid belt, which lies between Mars and Jupiter. 

Description

The mass of Ceres has been determined by analysis of the influence it exerts on smaller asteroids. Results differ slightly between researchers. The average of the three most precise values as of 2008 is 9.4×1020 kg.With this mass Ceres comprises about a third of the estimated total 3.0 ± 0.2×1021 kg mass of the asteroid belt,which is in turn about 4% of the mass of the Moon. The mass of Ceres is sufficient to give it a nearly spherical shape in hydrostatic equilibrium .In contrast, other large asteroids such as 2 Pallas, 3 Juno, and in particular 10 Hygiea are known to be somewhat irregular in shape.The surface composition of Ceres is broadly similar to that of C-type asteroids.Some differences do exist. The ubiquitous features of the Cererian IR spectra are those of hydrated materials, which indicate the presence of significant amounts of water in the interior. Other possible surface constituents include iron-rich clays (cronstedtite) and carbonate minerals (dolomite and siderite), which are common minerals in carbonaceous chondrite meteorites. The spectral features of carbonates and clay are usually absent in the spectra of other C-type asteroids. Sometimes Ceres is classified as a G-type asteroid. The Cererian surface is relatively warm. The maximum temperature with the Sun overhead was estimated from measurements to be 235 K (about −38 °C) on 5 May 1991. Diagram showing a possible internal structure of Ceres. Only a few Cererian surface features have been unambiguously detected. High-resolution ultraviolet Hubble Space Telescope images taken in 1995 showed a dark spot on its surface which was nicknamed "Piazzi" in honour of the discoverer of Ceres. This was thought to be a crater. Later near-infrared images with a higher resolution taken over a whole rotation with the Keck telescope using adaptive optics showed several bright and dark features moving with the dwarf planet's rotation. Two dark features had circular shapes and are presumably craters; one of them was observed to have a bright central region, while another was identified as the "Piazzi" feature. More recent visible-light Hubble Space Telescope images of a full rotation taken in 2003 and 2004 showed 11 recognizable surface features, the natures of which are currently unknown.One of these features corresponds to the "Piazzi" feature observed earlier. There are indications that Ceres may have a weak atmosphere and water frost on the surface. Surface water ice is unstable at distances less than 5 AU from the Sun,so it is expected to sublime if it is exposed directly to solar radiation. Water ice can migrate from the deep layers of Ceres to the surface, but will escape in a very short time. As a result, it is difficult to detect water vaporization. Water escaping from polar regions of Ceres was possibly observed in the early 1990s but this has not been unambiguously demonstrated. It may be possible to detect escaping water from the surroundings of a fresh impact crater or from cracks in the sub-surface layers of Ceres. Ultraviolet observations by the IUE spacecraft detected statistically significant amounts of hydroxide ion near the Cererean north pole, which is a product of water-vapor dissociation by ultraviolet solar radiation.

 History

 Terrain

 Climate

 Wildlife The only know native life form on Ceres are only 73 species of microbes, and by several strains of viruses. After the colonization of Ceres several new clade's of chimera organisms have been establish in the subterranean oceans of Ceres. The main organisms are Grustrapod (hybrid organisms that show the physical characteristics of a Gastropoda, and a Crustacea)that is mainly use as cattle & food source by the colonist in Ceres, and asteroids near Ceres. They are mainly feed from the artificial microbes colonies that live and are sustained by the hydrothermal vents.

 Colony