Tuesday, December 9, 2014

DAWN MEETS CERES FROM AFAR

 


 

A small world comprised of rock & ice inhabiting a region known as the asteroid belt, Ceres is the largest object in the region between Mars & Jupiter and about 950 kilometers in diameter. Ceres is of great interest for a possible destination for human colonization thanks to an abundance of water & minerals and NASA’s Dawn recently took some pictures from afar but plans to orbit her in 2015. Let’s take a minute and ponder the life to be had should we one day colonize this dwarf planet. Don’t know enough about her? Then read on!

 

Ceres started out as a mere asteroid. First discovered in 1801 by Giuseppe Piazzi, in a 19th century telescope, Ceres classified as an asteroid, though for a short time before that was a considered a small world/planet. When much later Hubble was able to resolve the 590 mile (950km) diameter body of Ceres into a disk she became a planet once again. (Albeit a dwarf planet.)

 

Now NASA’s Dawn is perched to uncover the mysteries of Ceres – held since the dawn of time.


 

Here’s what we already know:

 

·         The water amount Ceres holds is far more than that of Earth. This is apparent due to her oblateness (having an equatorial diameter greater than the distance between poles; compressed along or flattened at the poles.) This water is assumed an icy mantle and this theory is further supported by 2002 evidence from Keck telescope and evolutionary modeling.

 

·         This ‘oblateness’ also lends to the rockiness of her core.

 

·         Some characteristics of its surface & history (distance from the Sun, which weakened solar radiation enough to allow low-freezing-point components

·         to be incorporated during its formation), point to the presence of volatile materials in the interior of Ceres. –However this might also be explained by a porous or differentiated either partially or wholly interior.)

 

·         In 2014 several localized areas less than 60 km in diameter were discovered as sources of water vapor on Ceres. (Courtesy of the Herschel Space Observatory) This possibly indicates volcanic activity.

 

But could we find current occupants? This is always a possibility and perhaps made even more so by the geological history of Ceres. Dependant on heat sources both during and after her initial formation, the friction from planetesimal accretion, and decay of various radionuclides, add the presence of water ice and the speculation that life may exist there and there has even been the hypothesis that there is ejecta here on Earth that had its origins on Ceres.

 

Alas – the speculation, the wonder, the mystery – all will be solved or at least the journey to the answers begun when Dawn makes her arrival in 2015 – April to be precise.

 

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