Nylon cords lowered the rover to the ground in the "sky crane" maneuver. When the spacecraft sensed touchdown, the connecting cords were severed, and the descent stage flew out of the way.
The time of day at the landing site is about 3 pm local Mars time at Gale Crater. The landing marks the beginning of a two-year prime mission to investigate one of the most intriguing places on Mars.
NASA's most high-tech Mars rover zeroed in on the red planet where it attempted a tricky celestial gymnastics routine during "seven minutes of terror'' to plummet through the atmosphere.
The Curiosity rover was poised to hit the top of the Martian atmosphere at 21,000km/h. It was slowly lowered by cables inside a massive crater in the final few seconds.
NASA was ready for the "Super Bowl of planetary exploration,'' said Doug McCuistion, head of the Mars exploration program at NASA headquarters. "We score and win or we don't score and we don't win,'' said McCuistion.
Mission control at the NASA Jet Propulsion Laboratory was expected to hear a signal at 3.31pm.
The Parkes telescope in rural NSW - which was pivotal in the Apollo Moon landing in 1969 - is one of the sites receiving radio signals which reveals whether the landing had been a success. An antenna in Perth is also being deployed.
NASA's Sami Asmar, who is monitoring the landing from Parkes, said the landing of a very large rover onto the surface of another world, another planet was "complicated and many things can go wrong and NASA acknowledges that," he told the ABC.
Space fans gathered at a major deep space communications centre near Canberra to await the touchdown of Curiosity on the surface of Mars.
The Deep Space Communications Complex at Tidbinbulla, about 40km from the national capital, is playing a key role in the mission. It will be the first station in NASA's deep space network to receive signals from the rover after it lands.
Curiosity was launched to study whether the Martian environment ever had conditions suitable for microbial life. The voyage to Mars took over eight months and spanned 566 million kilometres. The trickiest part of the journey? The landing. Because Curiosity weighs nearly a ton, engineers drummed up a new and more controlled way to set the rover down.
The last Mars rovers, twins Spirit and Opportunity, were cocooned in air bags and bounced to a stop in 2004. The plans for Curiosity called for a series of braking tricks, similar to those used by the space shuttle, and a supersonic parachute to slow it down. Next: Ditch the heat shield used for the fiery descent.
And in a new twist, engineers came up with a way to lower the rover by cable from a hovering rocket-powered backpack. At touchdown, the cords cut and the rocket stage crashes a distance away.
Curiosity's goal: To scour for basic ingredients essential for life, including carbon, nitrogen, phosphorous, sulfur and oxygen. It's not equipped to search for living or fossil microorganisms. To get a definitive answer, a future mission needs to fly Martian rocks and soil back to Earth to be examined by powerful laboratories.