Marhofn 316.18 - May 2016

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Relative hills on the Moon

Alan Dawson and Daniel Patrick Quinn

In Marhofn 269, Phil Cooper speculated on the possibilities of bagging on Mars, outlining the challenges and costs of bagging 15000m high peaks, including the big one at over 27000m. It would seem prudent for aspiring extraterrestrial baggers to gain experience closer to home by tackling some of the more accessible Marilyns on the moon. Before undertaking such a challenge it is obviously essential to be properly equipped, with a list of the most prominent peaks, as it would be irritating to find out, after making all that effort, that the hills you climbed didn't count.

Establishing an accurate lunar list is more difficult than it is for Earth-centric hill listers. One of the many advantages of relative height is that you don't need sea level in order to come up with a valid list of relative hills, but you do need some reference point against which to measure the height of each hill. Surveying was not a high priority for Armstrong and Aldrin on their first attempt at exploration, and later explorers took along unhelpful ephemera such as golf clubs rather than surveying equipment. It was left to Grateful Dead lyricist Robert Hunter to try to quantify the lunar prominences in 'Mountains of the Moon' (Aoxomoxoa, 1969), but after a reasonable start with 'Twenty degrees of solitude, twenty degrees in all' he got sidetracked into 'Hi ho the carrion crow fol de rol de riddle' and other such impenetrable whimsy. Roger Waters (Dark Side of the Moon, 1973) astutely observed that 'The sun is the same in a relative way' but added little to lunar science. Now Dan Quinn has made a more helpful assessment in his new song, Marilyns of the Moon:

Here's a new challenge for all hill baggers yeah, yeah, yeah, yeah
A list for the moon, dear sirs and madams yeah, yeah, yeah, yeah
How many Marilyns are there on the moon? Yeah, yeah, yeah, yeah
Pretty slim chances, someone finishing soon yeah, yeah, yeah, yeah
Let's bag crazy, let's bag high risk yeah, yeah, yeah, yeah
See you in Moonhofn if you finish the list yeah, yeah, yeah, yeah

Woodall did you hear about this one?
Tell me, have you got them all done?
Remember your mask for moon hay fever
From the lunar dust

If you could bag the Marilyns of the moon
Marilyns of the moon
If you could be the first to finish the list
Then that would be cool

Wallace and Gromit went there digging for cheese yeah, yeah, yeah, yeah
They met an old cooker that started to plead yeah, yeah, yeah, yeah
'Stop all your eating of the hills of the moon yeah, yeah, yeah, yeah
It looks like Hensbarrow and there's just no need' yeah, yeah, yeah, yeah

Now, Woodall did you hear about this one?
Tell me, have you got them all done?
Remember your mask for moon hay fever
From the lunar dust

If you could bag the Marilyns of the moon
Marilyns of the moon
If you could be the first to finish the list
Then that would be cool

A virtual completer will get there soon yeah, yeah, yeah, yeah
Bag them all by proxy using Google Moon yeah, yeah, yeah, yeah
One giant leap but only in his mind yeah, yeah, yeah, yeah
No medal from Dawson for the cyber goon yeah, yeah, yeah, yeah

Now, Woodall did you hear about this one?
Tell me, have you got them all done?
Remember your mask for moon hay fever
From the lunar dust

If you could bag the Marilyns of the moon
Marilyns of the moon
If you could be the first to finish the list
Then that would be cool

So Daniel has set out the challenge and we have a name for the list - the Relative Elevations of the Moon (REMs). But there are still problems of definition. According to the list of mountains on the moon in Wikipedia, lunar summits have been measured to three different standards: 1737988, 1737400 or 1730000 metres from the centre of the moon. Rather more helpful is the estimation of a range of 18100 metres from the highest to the lowest point. Using the lowest point as a reference for quoting heights seems a reasonable solution to the absence of sea level. Yet the Wikipedia article confusingly asserts that the highest point, or Selenean summit (on the far side of the Moon), is 'approximately 6500 meters higher than Mons Huygens (usually listed as the tallest mountain)'. Clearly, there is a lot of work to be done.

Lack of wind, rain, bog and midges might make surveying on the moon more comfortable than in Scotland, but there are other problems. Altimeters are of little use given the absence of air pressure. GPS technology should in theory work ok on the moon, but the alignment of the GNSS satellite network is unhelpful for extra-terrestrial data collection. So far, there are no lunar base stations to facilitate the processing of survey data. Triangulation should work but there is no Newlyn datum to start from and there are no trig pillars. A laser level could be useful on the dark side, as long as one had a large supply of spare batteries, but navigation might be difficult.

The paucity of contour rings and spot heights on lunar maps means that working out col positions would be time-consuming, though the ability to leap large distances would be helpful. The absence of vegetation at cols and summits might enable reasonably precise measurements, but the depth of dust is unknown, so a shovel might be a useful accessory. Given the awkward life-support issues, and the difficulty of manipulating a keyboard or touch screen while wearing a space suit, it would be more practicable to assign a team of robot surveyors to the task than to rely on human tamperers. The problem with that strategy is whether one could trust a robot to make sure it had properly established the highest point of a summit, or the optimum col location, in accordance with the protocol set out in the Summits and Cols document. Could a robot reliably distinguish between an embedded rock and a movable one? The only way to be sure would be to assign a robot camera operator to film the survey process, interview the surveying robots and upload the resulting footage to MoonTube, where it could be assessed for validity by the designated earthbound database authority.

In view of these issues, it is a little premature to add the lunar summits to the hill-bagging website until there has been more research to define the REMs and arrange them into suitable sections using an agreed methodology. Still, the process has to start somewhere. At least we now have some understanding of the main problem areas, a name for the list and a song, so we are ready to move on to second base.

Summit of Hensbarrow Beacon waste tip (photo: Daniel Quinn)

Summit of Hensbarrow Beacon waste tip (photo: Daniel Quinn)

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