## 2 Moon Raw Material Surveying Strategy
### Carbon Deposits  
Another important raw material on the Moon is carbon. It will be important for the production of fuel for Starship vehicles [44], which use a mixture of liquid oxygen (LOX) and liquid methane (LCH4), i.e., the so-called metalox. Classic fuel using a mixture of liquid oxygen (LOX) and liquid hydrogen (LH2) has many disadvantages. Hydrogen is highly penetrating and after some time the so-called hydrogen poisoning of engine materials. Based on a fuel mixture containing hydrogen, it is much more difficult to develop a reusable rocket engine, and therefore, a reusable rocket with a cheap operating cost. Matalox has no such disadvantages. It is therefore expected that in the future, there will be more rockets powered by this fuel. After being launched into Earth's orbit, the Starship must first be refueled in orbit to continue its journey to further destinations (such as the Moon or Mars), just like before returning to Earth. Thus, lunar carbon deposits will be important for methane production. While carbon occurs in large quantities on Mars (even in the atmosphere, which contains 95.32% CO\({}_{2}\)), the situation is completely different on the Moon. Carbon is [45] present on the Moon in limited amounts, mostly as solar wind im-planted in the bulk regolith, and as carbon-bearing ices in the coldest regions at the poles. Carbon from the solar wind has a low concentration (about 100 ppm) and the resulting carbon deposits may amount to about 7 \(\times\) 10\({}^{13}\) kg in all surface regolith available near the lunar surface. In turn, polar carbon deposits may contain as much as 20% wt. C in the coldest regions, but are more likely to be in the range \(\sim\)0-3% wt. C. The total abundance of all these deposits may be approximately 1 \(\times\) 10\({}^{11}\) kg. The author presented an analysis [45] (Figure 7, p. 10) of how much material would have to be mined to produce enough carbon to fill the Starship with 1200 tons of methalox fuel for three different cases: bulk regolith, polar ice with the LCROSS composition, and a hypothetical carbon-bearing subsurface ice deposit with 50 wt.% ice and 6.5% CCOI. Currently known sources of carbon on the Moon are unlikely to support long-term human presence on the Moon. However, looking at the chemical composition of asteroids in the solar system, some of them are carbonaceous asteroids. It is therefore highly probable that there will be impact craters on the Moon containing fragments of large carbonaceous asteroids with high carbon content, which may be covered by a layer of regolith. New discoveries are not excluded and it may turn out that the Moon contains more carbon than is currently known.  
If we analyze the state of knowledge presented in this point, a certain pattern emerges as to where most of the valuable raw materials should be sought. Particularly interesting places are craters, especially the permanently shadowed regions (PSR) found in some of them, which can create cold traps. Of course, not every crater on the Moon contains permanently shadowed regions (PSR). It is assumed that the minimum latitude for the formation of permanently shadowed areas is 75\({}^{\circ}\) latitude, for the south and north poles of the Moon. The shape of the terrain must also enable the creation of permanently shaded regions (PSR) inside the craters. Not every permanently shaded regions (PSR) will be a good cold trap either, not to mention the exploration aspects which will be discussed later in the article. There is an observed relationship [46] between hydration and the content of TiO\({}_{2}\) and other elements. It is probable that the so-called \"sweet points\" will contain high concentrations of a few raw materials. Such places should be the starting point for a space mining mission on the Moon, as they offer a great chance to recoup the investment.