Not to detract from the discovery, but the poor editing of the headline already detracts from the headline. An exoplanet by definition is outside the "Earth's" solar system which is also redundant because the "solar" system is the stellar and planetary system that the earth is part of along with the sun which is why it is called the solar system, sol meaning sun.
Cut ‘em some slack, this was written for a college-aged audience, gotta spell everything out.