For those of you who aren't Trekkies, an M Class planet simply means a planet that is capable of supporting human life. I've painted this kind of planet several times now, but I have no desire to paint the Earth itself. I use painting as a way to escape, and any planet without COVID is a beautiful sight. :) They will look very similar, though, as humans are a finicky creature which requires every condition to be just-so in order to survive.
I've seen a TON of street art where artists use spray-paint to accomplish a pretty sweet space scene in just a few minutes...I think it's awesome, but I choose to go with the old-fashioned methods of technical brush work. If nothing else, it gives me more time away from the cares of planet Earth. :)