page_title: Sputnik Planitia
section_title: Bordering montes
hierarchical_section_title: Sputnik Planitia / Bordering montes
caption_attribution_description: English: A topographic image of the Sputnik Planitia basin, showing the rising scarps bordering the glacial plains. The banding is an artefact of the camera.
context_page_description: Sputnik Planitia, originally Sputnik Planum, is a high-albedo ice-covered basin on Pluto, about 1,050 by 800 km in size, named after Earth's first artificial satellite, Sputnik 1. It constitutes the western lobe of the heart-shaped Tombaugh Regio. Sputnik Planitia lies mostly in the northern hemisphere, but extends across the equator. Much of it has a surface of irregular polygons separated by troughs, interpreted as convection cells in the relatively soft nitrogen ice. The polygons average about 33 km across. In some cases troughs are populated by blocky mountains or hills, or contain darker material. There appear to be wind streaks on the surface with evidence of sublimation. The dark streaks are a few kilometers long and all aligned in the same direction. The planitia also contains pits apparently formed by sublimation. No craters were detectable by New Horizons, implying a surface less than 10 million years old. Modeling sublimation pit formation yields a surface age estimate of 180000+90000
  −40000 years.
context_section_description: On its northwest, Sputnik Planitia is bordered by a chaotic set of blocky mountains, the al-Idrisi Montes, which may have formed via the collapse of adjacent water ice highlands onto the planitia.
  On its southwest, the planitia is bordered by the Hillary Montes, rising 1.6 km (0.99 mi; 5,200 ft) above the surface, and, further south, the Norgay Montes, rising 3.4 km (2.1 mi; 11,000 ft) above the surface. These mountains also have a chaotic, blocky character. The mountains were named after Sir Edmund Hillary, New Zealand mountaineer, and Nepalese Sherpa mountaineer Tenzing Norgay, who were the first climbers to reach the summit of the highest peak on Earth, Mount Everest, on 29 May 1953. Some groups of hills in the basin are named after spacecraft; for example, “Coleta de Dados”, in honor of the first Brazilian satellite launched into space.
  Immediately to the southwest of the Norgay Montes (context) is a large, circular mountain with a central depression, Wright Mons. It has been identified as a possible cryovolcano.
caption: A topographic image of the Sputnik Planitia basin, showing the rising scarps bordering the glacial plains. The banding is an artefact of the camera.
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