It was around 2007-2008. The movie was translated into another language, but its original might be English. It was shown on TV, but there were no actors which are famous now (might be a movie from 90s or a bit later). It was in color.
The main things from the plot are:
1. The Moon was getting closer to Earth causing different gravity anomalies
2. Three astronauts had to explode it or somehow stop to save our planet
3. One of them landed on the Moon and made something (explosion probably) that splitted it into two halves
4. He also wrote something on the surface of the Moon (which was addressed to his girlfriend)
7 thoughts on “Moon is going to hit Earth and 3 astronauts fly to save it by splitting Moon into two parts”
It might be Deep Impact (1998) but it was a meteor. One of them landed on that to plant explosives.
Or Armageddon from the same year.
Impact (mini-series) 
It seems to fit most of the items in your list 🙂
Seems to be this one from the preview, I will check it out, thank you very much!
That was it, thanks!
We’ll call this Solved.
Yes, sorry for the late reply, the movie was indeed “Impact” (2009).