Venukah

[Humabout]

Also decide what you mean by "size." Most times when talking about planets this refers to mass or radius. If you mean half the surface area (something potentially more appropriate for mapping) that will mean something different, since sa is a function of the square of radius. Thus a planet with half the radius of earth will have a quarter the surface area to map and play with.

Is gravity substantially lower as well? This will affect mountain height and the amount of particulate suspended in the atmosphere (which may affect weather and erosion). It also tremendously affects the amount of atmosphere retained and the atmospheric pressure. This has an enormous impact on weather. A thinner atmosphere means crazy high winds potentially. It also has the unfortunate effect of limiting which volatiles the planet can retain. Water vapor could be escaping into space, resulting in shrinking - more likely - nonexistent surface water. It will also limit habitability.

Just some things to consider. Also remember, when considering the star orbited that uv light breaks down water, so high uv emitters like A class stars won't be very conducive to water bearing planets (this is not to mention their ephemeral lifespans).

This isn't intended to burst your bubble. I find that trying to abide by current planetological knowledge makes for more fascinating and alien worlds than just inventing things on the fly. Do some research and you might catch the bug too