Marc Kaufman, writing for National Geographic News:
The first planets discovered by Kepler were large gas giants like Jupiter that often orbited close to their suns.
Those early discoveries overturned a lot of assumptions about how solar systems could be organized, since the prevailing understanding had been that other solar systems resembled our own. That was why finding a Jupiter-like planet in the place where Mercury or Venus would be in our solar system was unexpected.
But as Kepler enters its fourth year of observing its selected stars, it is able to detect smaller planets with orbiting periods much longer than those found earlier in the mission.
This fantastic New York Times interactive depicts a handful of the 350 Earth-size planets identified by Kepler scientists. You can compare them to our solar system, too, which is at the bottom of the page.