Mars has a lumpy interior caused by 4.5-billion-year-old collisions, study shows

plNASA’s InSight lander was a robotic lander that operated from 2018 to 2022. The lander was built to detect seismic waves from marsquakes. These waves run deep into a planet’s mantle. As the waves pass through different kinds of materials within the mantle, their speed and waveform are altered.

During InSight’s operation, its seismometer detected 1,319 marsquakes. Researchers have since been studying the data to find out the composition of Mars’ mantle. A recent study published on August 28 revealed the lumpy nature of the red planet’s interior.

Scientists identified eight marsquakes that produced seismic waves with high-frequency energy. As the waves traveled deep within Mars’ mantle, they slowed down, returning scrambled signals. Researchers used planet-wide computer simulations to see where this was happening.

They discovered that the slowing down happened in a small, localized region. Further studies revealed that this region contains lumps of material. The scientists believe that the lumps were created from asteroid collisions that happened 4.5 billion years ago. There is a common belief that during those early years, asteroids and protoplanets regularly collided with younger planets.

Unlike Earth, Mars lacks tectonic plates. As a result, these lumps have remained there for that long. Venus and Mercury also lack tectonic plates. This study has given scientists insight into what might be present in their interiors.