Tolkien (crater)

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Photo of the northernmost part of planet Mercury, this shows the temperatures at the North Polar Region, which ranges from >400 K (red) to 50 K (purple). Tolkien is on the left of the image.
Planet Mercury
Coordinates 88°49′S 149°55′E / 88.82°S 149.92°E / -88.82; 149.92Coordinates: 88°49′S 149°55′E / 88.82°S 149.92°E / -88.82; 149.92
Diameter 50 km
Eponym J. R. R. Tolkien

Tolkien are one of the northernmost craters on Mercury located at 88.82 S, 211.08 W and is inside the Borealis quadrangle. It is 125 km in diameter and named after the South African born British writer J. R. R. Tolkien, notable for The Lord of the Rings trilogy. The name was approved by IAU's Working Group for Planetary System Nomenclature on August 6, 2012.[1]

Nearby craters are Kandinsky to the west, Tryggvadóttir touches the northern rim, Chesterton almost to the east, a larger unnamed crater with a central peak to the southeast, then south and a smaller one southeast. North of the crater is Mercury's North Pole, on the other side is Borealis Planitia (Northern Plain of Mercury). Also the crater's eastern rim almost touch the 180th meridian.


Tolkien features a central peak, first imaged through radar.[2]

Being predominantly permanently shaded, Tolkien along with the surrounding northern polar craters along with its southern polar craters are the coldest portions of Mercury with the lowest temperature of about 50 K (-233 °C) and being a crater of eternal darkness as the planet has almost no axial tilt. Evidence from MESSENGER and Earth-based observations indicate that water ice deposits are present in these cold craters including Tolkien.[3]

The crater along with that portion of the planet which were the two remaining uncharted polar portions of the planet was first discovered and imaged in around 2011 by the orbiter MESSENGER.

See also[edit]


  1. ^ "Tolkien". Gazetteer of Planetary Nomenclature. International Astronomical Union/USGS. Retrieved October 19, 2017. 
  2. ^ "Permanently Shaded Polar Craters". NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory. 15 November 2012. 
  3. ^ NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington (16 March 2015). "Hot and Cold". 

External links[edit]