Science, Maths & Technology
What do we know about the seven Earth-like planets?
...family are Earth-like in their density and not just their size. There is no way to be sure yet how much water most of them have, if any. Similarly, it’s hard to know whether any resemblance to Earth extends as far as having plate tectonics and a distinction between oceanic and continental crust (like Earth) or a more globally homogeneous crust (like Mars and Venus). The...