Is this a piece of news regarding world politics, sports, business, or science and technology?
Astronomers Spot Smallest Planets Yet American astronomers say they have discovered the two smallest planets yet orbiting nearby stars, trumping a small planet discovery by European scientists five days ago and capping the latest round in a frenzied hunt for other worlds like Earth.    All three of these smaller planets belong to a new class of "exoplanets" - those that orbit stars other than our sun, the scientists said in a briefing Tuesday... 
