If you look at the formulation for the ESI [1], you'll see that the components are mean radius, bulk density, escape velocity and surface temperature (measured

If you look at the formulation for the ESI [1], you'll see that the components are mean radius, bulk density, escape velocity and surface temperature (measured in Kelvins). Mathematically you could zero out one or all of the multiplicands (e.g. with a surface temperature of 0 degrees K) but constraining oneself to the realm of the possible, you'll always have a non-zero ESI. [1]: https://en.wikipedia.org/wiki/Earth_Similarity_Index#Formulation https://en.wikipedia.org/wiki/Earth_Similarity_Index#Formula...