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Between about 13,500 and 58,000 kilometers above Earth’s surface, billions of high-energy particles — predominately electrons — congregate to form the outer Van Allen Belt. Nearly 4,000 kilometers closer to Earth, the outermost boundary of its twin, the second Van Allen Belt, also encircles the planet.

Images and data sent back by NASA’s New Horizons spacecraft during its flyby mission to Pluto (and beyond) show a series of regularly spaced linear ridges sandwiched between a mountain range and Sputnik Planitia, a vast plain of nitrogen, carbon monoxide and methane ice. “When we first saw the New Horizons images, we thought instantly that these were dunes, but it was really surprising because we know there is not much of an atmosphere [on Pluto],” said Jani Radebaugh, a planetary scientist at Brigham Young University and co-author of a study in Science announcing the findings, in a statement.

Sixty years ago this month, a fleet of nine U.S. Navy ships with 4,500 people aboard maneuvered into the Atlantic. Eight of these ships continued to the South Atlantic, about 1,800 kilometers southwest of Cape Town, South Africa, while the ninth headed to the North Atlantic, near the Azores. The clandestine military operation — code-named Operation Argus — was not an invasion, but a scientific mission, carried out at a staggering pace and inspired by an unpublished research paper by an elevator engineer with an interest in accelerator physics.