Nine Moons

The (Long) Weekend Warrior: Nine Moons, 62 Hours ScienceDaily (Oct. 20, 2010) â€" Taking a long-weekend highroad trip, NASAs Cassini spacecraft successfully glided near nine Saturnian moons, sending back up a stream of raw images as mementos of its adrenaline-fueled expedition. The spacecraft direct back dissipateicularly intriguing images of the moons Dione and Rhea. The Dione and Rhea pictures atomic number 18 the highest-resolution views unless of part of their climbs. The views of the southern part of Diones leading hemisphere (the part of the moon that faces forward in its orbit around Saturn) and the equatorial region of Rheas leading hemisphere are more(prenominal) detailed than the last time we saw these terrains with NASAs Voyager spacecraft in the early 1980s. Of the five big icy moons of Saturn, Dione and Rhea are often considered a pair because they orbit close to to each one opposite, are darker than the others, and exhibit correspondent patterns of light reflecting off them. These newborn images, however, highlight the differences between these sister moons. Both images show similar geographic regions on each satellite. However, scientists can identify differences in geological histories of the two bodies from differences in the numbers and sizes of visible craters on their surfaces.

The number and size of craters on a bodys surface help indicate the age of that surface -- the more craters there are and the larger they are, the older the surface is. Rhea, for example, shows ancient, intense bombardments end-to-end this region. However, the same region of Dione is divided into distinct areas that exhibit variations in the number and size of preserved craters. In particular, while parts of Dione are heavily cratered like Rhea, there are other areas covered by relatively smooth plains. Those areas confuse umteen small craters, but few large impact scars, which indicates that they are geologically younger than the heavily cratered areas. The smooth plains must have been resurfaced at some point in... If you want to get a full essay, order it on our website: Orderessay

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