New Findings About Pluto:
New findings about Pluto have been reported by the National Aeronautics and Space Administration’s (NASA) New Horizons probe.
- The probe reported that icy lava flows have recently (no more than a billion years ago) covered substantial tracts of its surface.
- The findings drew particular attention to a mountainous feature named Wright Mons.
- The only spacecraft to visit Pluto is NASA’s New Horizons, which passed close by in July 2015.
- A mountainous feature named Wright Mons was found on Pluto, which rises 4-5km above its surroundings.
- It is about 150km across its base and has a central depression (a hole) 40-50km wide, with a floor at least as low as the surrounding terrain.
- Wright Mons, was informally named by the New Horizons team in honour of the Wright brothers.
- Scientists claim that Wright Mons is a volcano, and cite the lack of impact craters as evidence that it is not likely to be older than 1-2 billion years.
- An impact crater is formed when an object like an asteroid or meteorite crashes into the surface of a larger solid object like a planet or a moon.
- Its volume exceeds 20 thousand cubic kilometres.
- Although considerably less than the volume of Mars’s biggest volcanoes, this is similar to the total volume of Hawaii’s Mauna Loa, and much greater than the volume of its above sea-level portion.
- The slopes of Wright Mons and much of its surroundings are seen to be crowded with hummocks up to 1km high and mostly 6-12km across.
- Scientists conclude that these hummocks are made primarily of water-ice, rather than nitrogen- or methane-ice that covers some other young regions on Pluto.
- They argue that this is consistent with the material strength necessary to form and preserve these domes, but they do recognise small patches of much weaker nitrogen-ice, mainly in the central depression.
- The hummocks were likely created by some sort of ice volcanism, known by the technical term “cryovolcanism” – erupting icy water rather than molten rock.
- Pluto’s bulk density shows that it must have rock in its interior, but its outer regions are a mixture of ices (water, methane, nitrogen and probably ammonia and carbon monoxide, too, all of which are less than a third as dense as rock) in the same way that the crust of the Earth and other rocky planets is a mixture of several silicate minerals.
- Many other areas of Pluto have been around long enough to accumulate large numbers of impact craters – no recent icy lava flows have covered them.