This gives some more in depth information on how NASA is deploying the technique of photometry:

Astronomers using NASA’s Kepler Space Telescope have employed this technique to become the most successful planet-hunting spacecraft to date, with more than a thousand established discoveries and many more awaiting confirmation. Future missions carrying improved technology are now in the works.

How much can they tell us about alien planetary systems similar to our own?A great deal, according to a recently published study. It shows that in the best-case scenarios, these upcoming missions could uncover planetary moons, ringed worlds similar to Saturn, and even large collections of asteroids.

What do you think they will find in the future?