> That is some out of the box thinking!

Thanks. I'm just parroting some lines I read a decade or so ago on a website that I didn't manage to dig up again. (I wonder if it's still online?)

> I would say the key thing with Mercury is the ability to dig fast.

Why? What are you afraid of?

First, night lasts 88 (earth) days on Mercury. So if you start digging at dusk, you have plenty of time.

Second, Mercury's daytime surface temperature is around 430C (~ 800F ~ 700K). We have plenty of materials, like steel, that can withstand these temperatures easily. Even aluminum only melts at 660C.

So you make a parasol out of steel and span it over your equipment. Important: you make the parasol just big enough to shade your equipment, but otherwise let it see as much of the sky as possible.

Mercury has no atmosphere. So during the day you normally have a small patch of the sky at around 5772K, the sun. The sun has about ~6.6 times the angular area on the sky as from earth. The rest of the sky looks as if it's about 3K in temperature, ie very cold. The effect averages out to Mercury's 700K surface temperature.

The parasol itself will attain the same average temperature as the rest of Mercury's surface (because it's exposed to the same conditions).

But for anyone in the shade under the parasol will replace a patch of sky at 5772K where the sun used to be with one at only 700K where the parasol now blocks the view.

If your parasol is supposed to cover more than just a single point with its shadow, than it needs to be big. From the perspective of each shadow covered point, the parasol will have a bigger angular area than the sun it shades.

So you not only replace some 5772K area with 700K, but also some of the previously 3K area with 700K. Overall, you can probably set up things so that you get something like a balmy 15C on average.

> I would say the key thing with Mercury is the ability to dig fast.

To come back to this: Mercury has lower gravity than earth, so I expect that 'soil' will probably not be as dense?