NASA's online live broadcast reported InSight touched down on Mars at approximately 2:54 p.m. EST (1954 GMT), after a six-month, 300-million-mile (480-million-km) journey.
The lander plunged through the thin Martian atmosphere at about 2:47 p.m. EST (1947 GMT), heatshield first, and used a supersonic parachute to slow down. Then, it fired its retro rockets to slowly descend to the surface of Mars, and landed on the smooth plains of Elysium Planitia, Xinhua news agency reported.
InSight is being followed to Mars by two mini-spacecraft comprising NASA's Mars Cube One (MarCO), the first deep-space mission for CubeSats, which attempt to relay data from InSight as it enters the planet's atmosphere and lands.
At about 3 p.m. EST (2000 GMT), MarCO sent back the first picture of Mars.
InSight will detect geophysical signals deep below the Martian surface, including marsquakes and heat. Scientists will also be able to track radio signals from the stationary spacecraft, which vary based on the wobble in Mars' rotation, according to NASA.
InSight and MarCO flight controllers monitored and cheered for the spacecraft's successful entry, descent and landing from mission control at NASA's Jet Propulsion Laboratory in Pasadena, California.
It took the InSight team about four to five years to design and execute the mission, said an engineer at the mission control. He said the basic design of InSight was inherited from the Phoenix spacecraft, which landed on Mars on May 25, 2008.
To look deep into Mars, the lander must be at a place where it can stay still and quiet for its entire mission. That's why scientists chose Elysium Planitia as InSight's home, according to NASA.
The red planet is comparatively easy to land on and is less likely to melt equipment than Venus or Mercury, according to NASA.
Launched on May 5, InSight marks NASA's first Mars landing since the Curiosity rover in 2012 and the first dedicated to studying the deep interior of Mars.
InSight cruised 301,223,981 miles at a top speed of 6,200 mph, while being followed by two cube satellites, CNN reported.
"We've studied Mars from orbit and from the surface since 1965, learning about its weather, atmosphere, geology and surface chemistry," Lori Glaze, acting director of the Planetary Science Division in NASA's Science Mission Directorate, was quoted as saying.
"Now we finally will explore inside Mars and deepen our understanding of our terrestrial neighbour as NASA prepares to send human explorers deeper into the solar system."
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)