Our Place in Space: Tolkien Crater

Hello, friends!  Welcome to Our Place in Space: A to Z!  For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space.  If you don’t know what the A to Z Challenge is, click here to learn more.  In today’s post, T is for…


You would not expect to find water on Mercury.  If there ever was water on Mercury, you’d expect it to boil away into space pretty quickly.  I said the exact same thing about water on the Moon yesterday, and yet it turns out there is water on the Moon, trapped in ice form at the bottom of craters near the Moon’s north and south poles.  The same is true for craters near the north and south poles of Mercury.  To my eternal delight, one of those water-filled craters is named after fantasy author J.R.R. Tolkien.

By longstanding tradition, craters on Mercury are named after historically important artists, authors, and musicians.  There are a few exceptions, because a few craters were named before that tradition was established, but the vast majority follow the rule.  And so there’s a crater named after Shakespeare, and a crater named after Van Gogh, and a crater named after Mozart.  John Lennon has a crater named after him.  Walt Disney has a crater.  And so does J.R.R. Tolkien.

Tolkien Crater happens to be located near Mercury’s north pole.  As a result, the bottom of Tolkien Crater is perpetually shielded from sunlight by the crater walls.  It’s extremely dark and extremely cold—cold enough for frozen water to remain stable over cosmic time scales, despite Mercury’s lack of any significant atmosphere or Mercury’s proximity to the Sun.

In the distant future, as humanity spreads out across the Solar System, we may end up deciding to colonize Mercury.  Mercury has resources humans in the future may need: large quantities of metal and perhaps, also, large quantities of helium-3 (necessary for powering nuclear fusion reactors, assuming we ever figure out how to make nuclear fusion reactors work).  If humans do colonize Mercury, places like Tolkien Crater will be valuable real estate.

Most likely, human habitats on Mercury will be built underground.  It’s easier and safer to live underground than to live on Mercury’s surface.  As a result, I like to imagine that people living in and around Tolkien Crater will refer to their subsurface dwellings as “Hobbit holes.”  However, considering how important mining operations would be for a successful Mercury Colony, some sort of reference to the Mines of Moria might be more appropriate.

Let’s just hope those Mercury colonists do not delve too greedily or too deep, lest they awaken something slumbering in the darkness.

Want to Learn More?

Universe Today has an article on how and why we might colonize Mercury.  And here’s an article from Wired.com about the naming of Tolkien Crater.

Lastly, I feel that I have to mention this: if you haven’t seen a picture of Disney Crater, you really need to click here and see a picture of Disney Crater.