At the end of the day, the key difference between First Solar and SunPower the two largest U.S. solar panel makers is the cost structure.

FORBES: Solar Stocks That May Not Survive to 2014

First Solar, SunPower, and Evergreen Solar, all ended the day with modest gains of 1.4%, 1.1%, and 1.4%.

FORBES: Magazine Article

Its creators said the trip is the first attempt by a solar airplane capable of flying day and night without fuel to fly across America.

NPR: Solar Plane Leaves Calif. On Cross-Country Trip

Just a day after announcing the discovery of the first Earth-size planets ever detected outside our Solar System, scientists have confirmed the existence of two even smaller worlds.

BBC: Newly found planets are 'roasted remains'