Are you really like this? No one can be this obtuse. And once more, since you have the memory span of a goldfish, the VBW calc wasn’t for the calc, but the image posted that shows the size difference Let’s see, Elintir besides being a mirror copy of Earth, has enough mass for a gravity field that sustains an atmosphere suitable for life. Planets too small cant trap enough gasses with their gravity to make an atmosphere. Likewise, the Moon on Elintir has enough mass for a field of gravity to orbit the planet, behave just like our moon, and isn’t too small to be just pulled into the planet and not too big as to make it a binary system you get between two planets of equal mass