NASA’s Perseverance rover has uncovered evidence of an ancient, subsurface river delta on Mars, potentially offering a promising location to search for signs of past life. The discovery, made using the rover’s Radar Imager for Mars’ Subsurface Experiment (RIMFAX), suggests the delta lies buried tens of meters below the surface within Jezero Crater.
“I suppose this is a really promising place to appear for biomarkers,” said Emily Cardarelli, a astrobiologist at UCLA who led the team interpreting the RIMFAX images. “Microbial life likely evolved in environments like these.”
Exploring Below the Surface
Perseverance’s RIMFAX instrument emits radar waves into the Martian ground as the rover travels, sending a signal back to Earth with each 10-centimeter movement. When these radio waves encounter boundaries between different types of rock, ice, or sediment layers, signals bounce back. By analyzing the timing and strength of these reflections, scientists can create two-dimensional vertical slices of the subsurface, effectively creating an acoustic image of the Martian crust.
Between September 2023 and February 2024 – a period spanning over 250 Martian sols – Perseverance traversed a geological area known as the “Margin Unit.” This unit surrounds the inner edge of Jezero Crater, filling the space between the western fan deposits and the crater rim. The Margin Unit is rich in magnesium carbonate, a key reason Jezero Crater was selected as Perseverance’s landing site; on Earth, carbonates are excellent at preserving chemical signatures of life. “For example, you can think of the White Cliffs of Dover, which are all carbonate rock, and have a lot of fossils,” Cardarelli explained.
Published Date: 2026-03-20 17:18:00
Source Link: arstechnica.com
