The media has happily announced the scientific community’s plans to colonise the Moon, with the recent discovery of significant quantities of water hidden away in Moondust (or whatever it’s called).

A refuelling station, or a full-blown colony for lunar settlers, seems almost within grasp… sort of.

Mark Henderson wrote a great piece in today’s Times titled “Water, water everywhere, but the Moon is still drier than a desert.” I read this as I was putting the finishing touches to my incredibly nerdy spreadsheet, and it verified my own calculations that colonising the Moon is still further away than we’d all hope.

Given that water is contained only within the top few millimetres of soil on the Moon’s surface (source: The Times), that there is a litre or so of water in each metre cubed of soil (source: Science) and that the average colonist would need roughly 4 litres per day to survive in relative comfort (source: a Battlestar Galactica discussion forum), I came up with the following rather arresting stats:

• For each “colonist”, a football pitch’s worth of soil would need to be processed every 16 hours
• This is 12 metric tons of soil
• For a year this is 6510 metric tons, or 545 football pitches
• After this time, at maximum walking speed on the Moon and assuming you worked outwards from your initial location, it would take you 13.4 minutes to walk the two-thirds of a mile to the edge so you could brush your teeth that morning
• It would take 10 million years for that person to use all the water on the Moon
• By this time he would be very lonely and probably not smell very fresh

This is all based on many variables pulled from all over the net, and some I’ve just made up – for example it’s based on 75% extraction efficiency. Who knows if that’s entirely over- or under-estimating what would be realistic?

It also completely ignores other uses for that water, as suggested by the media, such as being electrolysed for use as rocket fuel.

The spreadsheet is on Google Docs so anyone can have a go. Please feel free to fiddle about, and let me know if any of it’s completely wrong or you have better ideas. Any better estimations of the variables would be welcome, but one thing’s for sure: we aren’t going to have self-sustaining colonies up there any time soon.

link to the Google Docs Spreadsheet

As reported in today’s Metro, we’re appealing to the public on this contentious issue: should you reboil or refill a kettle for that second cuppa? The best answer wins a trip down to London for two people to indulge in a British instution: tea at the Ritz.

There’s a huge body of opinion that maintains a bad-tasting brew is inevitable if you reuse water once boiled – some say it rids the water of taste-enhancing dissolved oxygen gas. There are others who heard from their grannies that reboiled water causes cancer.

But some say that the difference in taste and composition is minimal, and a new draught of water is just a waste of a precious resource – not to mention more expensive. Still others say it makes no difference at all!

Arguments about limescale, dissolved gases… surely this is just chemistry, yes? So there must be a scientific explanation for all this.

Explain your choice of reboiled or reused water, in a clear and scientific manner, in a comment to this post. The answer we judge to be the best will win a trip for two to London, and tea at the Ritz hotel on Piccadilly – incidentally just a few steps down the road from home of the RSC, Burlington House.

We’ll be closing comments on 30 June, so pull up your favourite search engine, give your granny a ring and present your theory below!

Click here if you can’t see the comments box.