The technology at this point may not be quite good enough to detect a ‘earth-sized’ planet within the Goldilocks Zone. This planet is the smallest they have found so far. That doesn’t mean there aren’t any smaller, it’s just that they cannot yet detect them. If you read the full article, another team, using a different system, analyzed this same planet and their indications are that it is even smaller than Spitzer’s team’s calculations.........
Ironic that the planets they can detect, the “hot Jupiters”, cannot exist in the current secular theory of solar formation.