![]() ![]() He added that it's not the frontier of the solar system as Patrick Moore suggested, but the "gateway" to the unexplored realm of the Kuiper Belt.Īnd it may be that dunes themselves were emerging as a fascinating new feature of space exploration. He quoted the late Sir Patrick Moore, the famous BBC Sky at Night presenter, describing Pluto in 1955 as "…plunged in everlasting dusk, silent, barren, and touched with the chill of death…" and says that that perspective has to shift. That sentiment was echoed in an article accompanying the Science paper by Professor Alexander Hayes, an astronomer at Cornell University in Ithaca, US. "It's really exciting just to be able to look at this world and recognise that it's not just a frozen icy blob in the outer reaches of the solar system but really we're seeing a dynamic world still changing, still forming today," he said. (4) NASA/JPL-CALTECH/ASIĭr Telfer said the analysis provided a new insight to Pluto and also changed our view of it. Photo: NASA NASA/JPL/UNIVERSITY OF ARIZONA GREELEY ET AL. Similar dune-like patterns have been found on Solar System bodies including planets, moons, and a comet that all have very different gravity, atmospheric pressures, and sediment types. With that warming of the ice below the surface, methane crystals should enable nitrogen ice to sublimate - and that would allow the methane crystals to be wafted into the atmosphere. They believed that the dunes were composed of grains of methane, and maybe of nitrogen as well, and that a "reservoir" of methane may exist in the snowpack of the mountains.Īs for the process of "lofting" the grains off the ground, the paper suggested that the driver could be a slight warming from the distant Sun, raising the temperature above the frost point of nitrogen: -230C. The wind is generated as air flows downhill from the neighbouring mountains and also as frozen material sublimates - or turns directly into gas. To be able to form, dunes need an atmosphere dense enough to make wind transport possible, a supply of dry particles, and a mechanism that lifts particles off the ground.Īt first sight, none of those conditions seem to be met on Pluto.īut Dr Telfer and his colleagues calculated that the dunes may be in one of the windiest areas of the Pluto with wind speeds reaching up to 10m/sec - enough to keep particles moving. "We can feed all that back into a physical model and from that deduce what the size of the grains must be." "And we can measure some basic things like how far apart they are spaced, and have an estimate at least of the wind speeds that are forming them. ![]() He told the BBC: "We can't see individual grains but what we are able to identify dunes, and characterise their basic physical parameters, and the density of the atmosphere that they've been formed under. The paper's lead author is Dr Matt Telfer, a physical geographer at the University of Plymouth. The scientists concluded that the dunes were 0.4km-1km apart and that they were made up of particles of methane ice between 200-300 micrometers in diameter - roughly the size of grains of sand. They were lying close to a range of mountains of water ice 5km high. In their study, the researchers explained how they studied pictures of a plain known as Sputnik Planitia, parts of which were covered with what look like fields of dunes. The findings come from analysis of the startling images sent back by Nasa's New Horizons mission, which flew close to Pluto in July 2015.Īfter an epic trek through the solar system that took nearly a decade, New Horizons sped by at a speed of 58,536 km/h, gathering data as it passed. Pluto's atmosphere was believed to be too thin to create the features familiar in deserts on Earth. The research, which is published in the journal Science, suggests that the distant world is more dynamic than previously thought. Photo: NASA/JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS LABORATORY/SOUTHWEST RESEARCH INSTITUTE/ZLDOYLE In this image of Pluto's surface, the red luminance corresponds to the infrared data acquired by the Ralph/MVIC instrument carried by New Horizons. ![]()
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