CAPE CANAVERAL, Florida  — NASA's Mars rover was on its final approach to the red planet on Sunday, heading toward a mountain that may hold clues about whether life has ever existed on Mars, officials said.

The rover, also known as Curiosity, has been careening toward Mars since its launch in November. The nuclear-powered rover the size of a compact car is expected to end its 352-million-mile (567-million-km) journey on August 6 at 1:31 a.m. ET.

The landing zone is a 12-mile-by-4-mile (20-km-by-7-km) area inside an ancient impact basin known as Gale Crater, located near the planet's equator. The crater, one of the lowest places on Mars, has a 3-mile-high (5-km-high) mountain of what appears to be layers of sediment.

Scientists suspect the crater may have once been the floor of a lake.

If so, they believe that sediments likely filled the crater, but were carried away over time, leaving only the central mound.