Composition determines density. A rocky planet would block less light than a gas giant planet of the same mass, because it would be denser and therefore smaller.
But does density have to do with anything Kepler measures?
Since it only measures how much light decreases, I assumed it's only measuring planet size, and that we're totally ignorant about planet mass and density?
Since it only measures how much light decreases, I assumed it's only measuring planet size, and that we're totally ignorant about planet mass and density?