pia24318-08-powereddescent-2000
Fernando and colleagues calculated the signals that might be produced from the sonic boom and found them unlikely to be detectable by Insight. However, the 154-pound (70-kilogram) CMBDs will be jettisoned over 620 miles (1,000 kilometers) above the surface of Mars, and should produce small craters when they impact the planet at high speed.
NASA

The actual touch down of Perseverance is meant to be a soft landing that shouldn’t be detectable over a long distance, but the more energetic parts of the process Fernando refers to include the sonic boom from the spacecraft as it decelerates during descent, and the impact of two large weights called Cruise Mass Balance Devices, aka CMBDs.

The Mars Insight lander is located less than 2,000 miles (about 3,000 kilometers) away from Jezero Crater, where Perseverance is set to land. Unlike the more charismatic rovers that are designed to roll around and explore the Martian landscape, one of Insight’s primary jobs is simply to sit in one spot and listen for marsquakes and other seismic activity.

An illustration of Perseverance during its descent to the Martian surface.
From the lab to your inbox. Get the latest science stories from CNET every week.

“This will transmit a huge amount of energy into the ground, which will produce seismic waves,” Fernando explains. “We estimated that these signals will be ‘loud’ enough to be detected by InSight’s seismometers about 40% of the time in the best-case scenario. The uncertainties of our estimates are significant, mainly because no one has ever tried to detect an impact event at these distances before.”
Regardless of how well it works, even attempting to detect a spacecraft landing on Mars with another distant probe will be a first.