Now, a complete analysis of images and topographic data suggests that this is not an ice volcano, but a fusion of many – some up to 7,000 meters high and about 10-150 kilometers wide. Their discovery has sparked another debate: what could keep Pluto warm enough to support volcanic activity? Sitting on the southern edge of a huge layer of heart-shaped ice, these unusual surface features were first spotted when NASA’s New Horizons spacecraft passed in July 2015, providing the first close-up images of the icy former planet and its moons. “We were immediately intrigued by this area because it was so different and impressive,” said Dr. Kelsi Singer, co-researcher at New Horizons and associate research scientist at the Southwest Research Institute in Boulder, Colorado. “There are these giant wide mounds, and then this humorous texture that looks like humor on top. and even above that there is a smaller kind of textured boulder. “ At the time, an ice volcano seemed like the least bizarre explanation for these features – there were no crater craters from asteroids or meteorites nearby, suggesting that these features had been erased from relatively recent geological events. and no slate masonry – a key factor in the formation of mountains on Earth. However, Singer and her colleagues were cautious about calling them volcanoes. “It is theoretically possible, but there are not many other examples in the solar system, and they all look really different and do not look like Pluto.” Since the release of these first images in 2015, many more have arrived, along with elements of composition and topography. Taking all this together, the team concluded that these unusual features are actually volcanoes – although their appearance and behavior are very different from those found on Earth. “If you look at Mount Fuji from a distance or one of Hawaii’s volcanoes, they look like these big, wide, smooth features, which is not what we see there,” said Singer, whose findings are published in Nature Communications. “Well, we believe, the material is probably being pushed out from below and the canopy is growing from above.” As for the nature of this material, the composition data suggest that it is mainly water ice, but with some additional “antifreeze” ingredients mixed, such as ammonia or methanol. “It’s still hard to think it would be wet, because it’s very cold – the average surface temperature on Pluto is about 40 Kelvin (-233 C),” Singer said. “Well, it’s probably more, either muddy material, or it could be mostly solid – like a glacier is solid, but it can still flow.” Even that is quite strange, he added, because, given the extremely low temperature, this material should not be mobile at all. Probably suggests that Pluto’s rocky core is warmer than expected and that the thermal energy released by radioactive decay some of its elements are trapped, for example, by an insulating layer of material and periodically released, erupting volcanoes. These are all conjectures. “I will admit that we do not have much information about what is going on in Pluto’s subsoil,” Singer said. “But it does make people come up with creative ideas for how to do it [ice volcanism] it could happen. “ Whatever the explanation, Pluto’s old-fashioned idea of just an inert ball of ice seems increasingly unlikely.
