World News Korner

CAPE CANAVERAL, Fla. — NASA's newest robotic explorer, Maven, rocketed toward Mars on Monday on a quest to unravel the ancient mystery of the red planet's radical climate change.

The Maven spacecraft is due at Mars next fall following a journey of more than 440 million miles.

Scientists want to know why Mars went from being warm and wet during its first billion year to cold and dry today. The early Martian atmosphere was thick enough to hold water and possibly support microbial life. But much of that atmosphere may have been lost to space, eroded by the sun.

"We want to know: What happened?" said Michael Meyer, NASA's lead Mars scientist.

To help solve this environmental puzzle, Maven will spend an entire Earth year measuring atmospheric gases once it reaches Mars on Sept. 22, 2014.

This is NASA's 21st mission to Mars since the 1960s. But it's the first one devoted to studying the Martian upper atmosphere.

The mission costs $671 million.

Maven — short for Mars Atmosphere and Volatile Evolution, with a capital "N'' in EvolutioN — bears eight science instruments. The spacecraft, at 5,410 pounds, weighs as much as an SUV. From solar wingtip to wingtip, it stretches 37.5 feet, about the length of a school bus.

A question underlying all of NASA's Mars missions to date is whether life could have started on what now seems to be a barren world.

"We don't have that answer yet, and that's all part of our quest for trying to answer, 'Are we alone in the universe?' in a much broader sense," said John Grunsfeld, NASA's science mission director.