Mission controllers at the agency's Jet Propulsion Laboratory in Southern California were unable to contact the lander after two consecutive attempts, which led them to conclude the spacecraft's solar-powered batteries had run out of energy - a state engineers refer to as "dead bus."
NASA had previously decided to declare the mission over if the lander missed two communication attempts.
The last time InSight communicated with Earth was on Dec. 15, according to NASA.
InSight was launched in May 2018 to study the deep interior of Mars. It touched down safely on the Red Planet in late November 2018, marking NASA's first Mars landing since the Curiosity rover in 2012.
Insight has detected about 1,300 marsquakes, and made countless scientific discoveries in the past more than four years, according to NASA.
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