NASA's Perseverance rover, using its ground-penetrating radar instrument RIMFAX, has discovered evidence of a buried river delta beneath the Jezero Crater on Mars.3
Layers hidden beneath the surface have been discovered; they reveal structures formed when water flowed into a lake on ancient Mars.
Scientists say that this underground delta could date back 3.7 to 4.2 billion years; this suggests that Mars holds the most ancient evidence regarding the presence of water.
Scientists selected Jezero Crater for exploration, as orbital images had already indicated the presence of an ancient lake and delta suitable for preserving biosignatures.
The rover imaged the subsurface geology along a portion of its path, helping researchers view hidden sedimentary layers that are invisible to the naked eye.
These layered deposits support the evidence that Mars once had a warm, humid climate characterized by rivers, lakes, and active sedimentation.
The subsurface delta appears to be more ancient than the western delta visible from orbit, revealing a more complex and prolonged history of water.
Ancient deltas are of immense significance, as such discoveries preserve chemical or fossil evidence related to past microbial life.
Using radar data collected during the Perseverance rover's drives in Jezero, researchers have demonstrated that subsurface imaging can profoundly transform planetary exploration.
This discovery strengthens the argument that environments suitable for the existence of life once existed on ancient Mars.