What is going on with that mountain? New images taken by NASA’s Dawn spacecraft from its new, lower science orbit of just 915 miles (1,470 km) reveal fresh and puzzling details on the conical mountain that towers 4 miles (6 km) high over the dwarf planet Ceres. Its slopes show bright streaks, the top appears fractured, but what’s really odd is the lack of debris at the mountain’s base. Why does it appear to end so abruptly? And why is it the only tall peak on Ceres?
Maybe it’s just a matter of resolution. Things look smoother and less bumpy from farther away. Closer views presumably will show a rougher surface, but their “polished” appearance strikes one as peculiar to say the least. Take a look at the crater just below the mountain. It interior slopes also appear smooth, but that’s undoubtedly due to lack of sharpness at this altitude. It’s fascinating to see how rock has tumbled down the crater’s walls and mounded in its center. In both mountain and crater, what rolls downhill has been broken into smaller pieces below the camera’s resolution at its current altitude.
Funny isn’t it, that every time we drop down for a closer look at Ceres, the sharper views gained don’t necessarily solve the mystery. Like those Russian nested wooden dolls, where you open one to find another one inside, each step closer to the dwarf planet forces a new question.
While no new pictures of the enigmatic white spots have been published yet, other images snapped by Dawn from 915 miles up show a sunken crater and a mountain ridge poking up from the floor of a large crater. The spacecraft has also been busy mapping out Ceres’ mineral makeup, while engineers and scientists work to refine their measurements of Ceres’ gravity field. The gravity information will help mission planners design Dawn’s next and lowest orbit and how it will get there. In late October, the probe will begin spiraling to down to an altitude of 230 miles (375 km), as low as it will go.
Now that Dawn has settled into its new mapping orbit, expect clearer photos of the white spots very soon.