NASA's JPL has safely landed the Mars Science Lab - dubbed Curiosity - at Gale Crater, which lies near a mountain that scientists hope the rover will be able to climb in the search for sediment layers that could be up to a billion years old. Curiosity is designed to hunt for soil-based signatures of life and send back data to prepare for a future human mission. NASA hopes to have some low-resolution black and white images taken from cameras on the rear of the rover shortly.

The landing site for the rover is a flat area known as Gale Crater. NASA monitored the landing sequence in detail using a series of timed tones that indicated a critical event had occurred - landed safely at 0531 GMT - Monday August 6. (22:31 Pacfic/Sunday). That was about 14 minutes after the touchdown actually happens due to the time it takes for spacecraft signals to travel from Mars to Earth.

NASA's $2.5 billion dream machine, the Mars Science Laboratory, aims to take the first steps toward finding out when it nears Mars's surface on Monday.

Scientists have found signs of water on Red Planet, which is Earth's neighbor, hinting that some form of life was once likely even though Mars is now a dry place with a thin atmosphere, extreme winters and dust storms.

"Curiosity remains in good health with all systems operating as expected," NASA said in a statement.

The nuclear-powered rover is the biggest ever built for planetary exploration - weighing in at one ton, about the size of a small car - and carries a complex chemistry kit to zap rocks, drill soil and test for radiation.

The landing was a daring and unprecedented maneuver that involves penetrating the atmosphere at a speed of 13,200 miles per hour, slowing down with the help of a supersonic parachute and dropping down gently with tethers from a rocket-powered sky crane.

"This was the most challenging landing we have ever attempted," said Doug McCuistion, director of NASA's Mars Exploration Program.

Two NASA orbiters were crossing overhead as the lander approaches the surface, and a third orbiter operated by the European Space Agency will also send data back to Earth.

The Mars Science Laboratory began its journey more than eight months ago when it launched from the Florida coast in late November 2011.

"Can we do this? Yeah, I think we can do this. I am confident the team has done an amazing job," he said. "But risk still exists. It is going to be tough."

NASA detailed the final minutes of the complex landing in an Internet video called "Seven Minutes of Terror."

The landing site for the rover is a flat area known as Gale Crater, which lies near a mountain that scientists hope the rover will be able to climb in the search for sediment layers that

One potential factor of concern was the weather, but that appears to be cooperating after a nearby dust storm spotted days ago dissipated, deputy project scientist Ashwin Vasavada told reporters. "Mars played nice and we had good conditions for Sunday," he said.

More images will follow in the coming days. Then, engineers on Earth will spend most of August remotely checking out systems on the vehicle, according to deputy program manager Richard Cook.

The rover is carrying a chemistry kit that contains a rock-zapping laser, 17 cameras, a drill, radiation detectors, water sensors, and tools to scoop soil and check for carbon-based compounds that are the building blocks for life.

Curiosity may start to roll for its first drive in September, with its first scoop samples expected late in the month and its first drilling attempt in October or November.