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After making groundbreaking discoveries about the mysterious interior of the red planet, the InSight lander’s mission has officially ended.

The stationary lander spent nearly 1,500 days on Mars. Mission managers declared the program’s end on Wednesday after the lander failed to respond to two messages from mission control at NASA’s Jet Propulsion Laboratory in Pasadena, California.

The mission, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, ended more than four years after it first landed on November 26, 2018.

Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington, said in a statement that “while saying goodbye to a spacecraft is always sad, the fascinating science InSight conducted is cause for celebration. The seismic data alone from this Discovery Program mission offers tremendous insights not just into Mars but other rocky bodies, including Earth.”

Designed to last for only two years, InSight’s mission was extended twice. But a heavy accumulation of dust on its solar panels caused a steady drop in the lander’s power source.

Mars is a frigid desert where weather is driven by swirling dust. Over the course of InSight’s time on Mars, it survived dust storms and swirling dust devils. The clever mission team, and wind on Mars, helped clear the solar panels from time to time.

Eventually, nothing could keep the red dust from building up an impenetrable layer on InSight’s solar panels, as captured by one of the mission’s final selfies in April.

Despite these challenges, InSight conserved power to keep capturing science from its home in a plain called Elysium Planitia along the Martian equator. Slowly, it shut off its instruments, one by one, while listening for the rumble of Marsquakes to the very end.

Unlike its roaming rover cousins, InSight was designed to stay in its landing spot and perform the first “checkup” of Mars, bedecked with 7-foot solar arrays, a suite of instruments and a robotic arm.

InSight made history by detecting the first quakes on another planet and heard Mars rumble more than 1,300 times during its mission.

Marsquakes are like the earthquakes we experience on Earth, just a little bit different when it comes to why they occur on each planet.

When we experience earthquakes, it’s because the tectonic plates on Earth are shifting, moving and grinding against one another. So far, Earth is the only planet known to have these plates.

Think of the Martian crust as a single giant plate. This crust has faults and fractures within it because the planet continues to shrink as it cools. This puts stress on the Martian crust, stretching and cracking it.

The lander’s incredibly sensitive seismometer, called the Seismic Experiment for Interior Structure, could detect marsquakes from hundreds and thousands of miles away.

In May, InSight captured “the big one,” a marsquake with a magnitude of 5, which sent vibrations through the planet for at least six hours.

InSight also heard space rocks as they slammed into Mars and left behind fresh, gaping craters. One revealed a treasure trove of buried ice near the warm Martian equator.

When the seismic waves of marsquakes traveled through different materials within the Martian interior, it allowed scientists to study the planet’s structure.

The data collected by InSight also revealed new details about the unexplored Martian core, mantle and crust, including why Mars’ core is still molten. The findings can shed light on whether it was ever able to support life and how rocky planets like Mars and Earth formed in the solar system.

It wasn’t always an easy path for the lander and its instruments.

“The mole,” or the self-hammering heat probe, was designed to reach at least 16 feet beneath the surface to record how heat escapes from the interior, according to NASA.

The InSight team tirelessly tried every trick in the book, including banging on it, to send the Heat Flow and Physical Properties Package beneath the Martian soil for nearly two years. But the soil’s odd clumping prevented the mole from having the friction it needed and it was essentially retired in January 2021.

Although dust ultimately ended InSight’s mission, as with other solar-powered Martian robotic explorers like the Opportunity rover, the lander made an in-depth study of its enemy.

InSight collected the most comprehensive weather data of any mission sent to the surface of Mars, according to NASA.

Over four years, it captured daily weather forecasts on Mars, recorded the eerie sounds of wind, rode out Martian winters, and observed thousands of sunrises and sunsets.

InSight has allowed scientists a more complete picture of Mars and gathered information that will be instrumental when humans land on the red planet.

“We’ve thought of InSight as our friend and colleague on Mars for the past four years, so it’s hard to say goodbye,” said Bruce Banerdt, the mission’s principal investigator. “But it has earned its richly deserved retirement.”