Ceres (Dwarf Planet)


Ceres, minor-planet designation 1 Ceres, discovered on January 1, 1801, by Giuseppe Piazzi an Italian astronomer, and named after the Roman goddess of the harvest, growing plants and motherly love, was on August 24, 2006, officially declared by the IAU to be a "dwarf planet." [1] [2] [3]

The diminutive orb is
located in the asteroid belt at an average distance of 413,832,587 kilometers (2.77 AU) from the Sun and with a diameter (newly revised by Dawn) of 940 kilometers (584 miles) is the smallest body in the new category, roughly a quarter the size of Earth's moon.

Studies would seem to indicate that Ceres has a rocky core covered by an icy mantle which could contain in frozen form more water than all of Earth's oceans. Even so, with little or no atmosphere and a maximum surface temperature of -38 degrees Celsius the dwarf planet offers little hope for indigenous life. It does, however, due to the ready availability of ice from which fuel, oxygen and water can be easily derived offer
in the form of enclosed habitats possibilities for human colonization.


[1] Ceres, at first thought to be a comet has been reclassified more than once. Listed as a planet in order to conform to Bode's law, a now failed hypothesis, it was reclassified as an asteroid in the 1850s.

[2] A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round shape), (c) has not cleared the neighborhood around its orbit and (d) is not a satellite.

[3] The Dawn mission, a space probe launched by NASA in 2007, is now (as of March, 6, 2015,) orbiting Ceres. The mission which began orbiting Vesta (4 Vesta) on July 16, 2011, succesfully completed its 14 month Vesta survey in late 2012 and has now, following a two and a half year journey, arrived at its primary destination the first Earth craft to visit a dwarf planet up close and personal.

[b] The stopover at Vesta
(the belts second most massive object and the brightest asteroid visible from Earth) has revealed or confirmed a number of surprising and in some cases unique features: Vesta has a mountain three times the height of Everest, is covered in a layer of dust, soil and broken rock called regolith, rotates on its axis (unlike most asteroids) and is structured like a rocky planet with an iron core, a silicate mantle and an outer basaltic crust.

It's possible that Vesta may be classified as a dwarf planet by the International Astronomical Union (IAU) at a future time if it's convincingly determined that its 
nearly round shape is a product of its mass/self gravity overcoming rigid body forces (the southern hemisphere's enormous impact craters Rheasilvia and Veneneia notwithstanding); indeed observations by Dawn seem to indicate that Vesta is a transitional body somewhere between a large asteroid and a small planet. 

[c] It's likely (a connection confirmed by the Dawn spacecraft) that the impact which created Rheasilvia produced the howardite-eucrite-diogenite (HED) achondrite meteorites found on Earth.
 

* New images of Ceres returned by Dawn are stiring up more questions than answers. Mysterious bright spots and a four mile (six km) high glowing triangular mountain have scientists baffled. What does it all mean? "We don't know," says Nasa "yet." Aliens or ice volcanoes the coming months are going to be very exciting.





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