A new U.S. probe to Mars has been launched from Cape Canaveral, Florida.
The spacecraft, called "Maven," is expected to reach Mars in 10 months, then circle the red planet for a full Earth year to examine its upper atmosphere.
The craft's elliptical orbit will drop as low as 125 kilometers above Mars to sample the atmosphere and extend as high as 6,218 kilometers.
Scientists want to learn how Mars transformed from a warm, wet planet a few billion years ago into the dry, cold world of today as its atmosphere went from thick to thin.
Scientists believe much of the atmospheric gas may have escaped into space as a result of solar activity.
the "Maven" as a roughly 2.4-meter "cube weighing about [2,450 kilograms] at launch -- as much as a fully loaded sport utility vehicle. With its twin pairs of gull-wing-shaped solar panels extended, it stretches 37 feet [11.3 meters] from wingtip to wingtip."
Based on reporting by AP and RFE/RL