Impactor Debris Scattered Within Mars' Mantle (Artist's Concept)

This not-to-scale artist's concept depicts a cutaway view of Mars' interior, revealing the crust, mantle, and core. Debris from ancient impacts lies scattered in the mantle in the form of lumps that are as large as 2.5 miles (4 kilometers) across, data from NASA's InSight Mars lander shows. On the Martian surface at left, a meteoroid impact sends seismic signals (shown as curving concentric lines) through the planet; InSight is depicted at right. InSight placed the first seismometer on Mars' surface in 2018. The extremely sensitive instrument recorded 1,319 marsquakes before the lander ran out of power in 2022, the result of dust caked on its solar panels. Quakes produce seismic waves that change as they pass through different kinds of material, providing scientists with a way to study the interior of a planetary body. To date, the InSight team has measured the size, depth, and composition of Mars' crust, mantle, and core. The impact debris in the Martian mantle offers a geologic record that could be preserved only on worlds like Mars, whose lack of tectonic plates has kept its interior from being churned up the way Earth's is through a process known as convection. https://photojournal.jpl.nasa.gov/catalog/PIA26636