IAO 2000, Практически тур, Група α — Задача 2. A "DRILLING" OF THE MOON WITH THE HELP OF RATAN

Introduction:

Dear students, you are to see the first colonies on the Moon. The areas of the Moon surface consisting of oxygen-bearing rock are already being searched for them. First of all these are ilmenite basalts. Beside oxygen (10% from the weight) the ilmenite (FeTiO₃) can give a pure iron.
With the help of the radio telescope RATAN-600 a "radio drilling" of the Moon was carried out: unlike the visible light, radio waves come from under its surface. The depth of the "drilling" increases with the increase of wavelength. At the wavelength of 1 cm the Moon is transparent down to 0.5 m, at 30 cm – down to 10 m. The regions with increased content of ilmenite are also distinguished by an increased radio emission level.
Fig.1 presents radio cuts of the Moon obtained at its passage through the "knife" beams of RATAN. From the 6 used wave lengths only 3 are presented, since the cut at 2.1 cm almost repeats the cut at 1.4 cm, and the cuts at 3.9 and 31 cm differ little from the cut at 8.2 cm. The last could be said also about 13-cm cut, but at the moment of observation the transmitters left at the Moon by American astronauts were operating, exactly at this wavelength.
The cuts at different wavelengths can be compared both to each other and to the seas and continents known to you in the image of the Moon in visible light. A band covered in the observations at 1.4 cm is marked in it. In other wavelengths the beams cover the entire disk of the Moon in altitude. The positions of transmitters operating at the wavelength of 13 cm are also shown.

Task:

What transmitters were operating at the moment of observation?

What is the difference in the image of the Moon in cm wavelength from its image in visible wavelengths? What is the reason for it?

What region would you recommend for the settlement of first colonies?