A stunning map of this distant, diminutive planet , the first based on direct images, was revealed late last week in a Hubble Space Telescope press release . The grid pattern is due to the computer technique used where each grid element is over 100 miles across. The map is based on Hubble images made when Pluto was a mere 3 billion miles distant. It shows strong brightness variations - confirming and substantially improving upon ground based observations . While the brightness variations may be due to surface features like craters and basins they are more likely caused by regions of nitrogen and methane frost.
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