Podcast Episode
The discovery came from analysing the so-called Margin unit that lines the crater's inner edge. Scientists found that the rock began as molten material from a magma chamber or lava lake. After cooling, minerals within were transformed by circulating carbon dioxide-rich underground water, creating iron and magnesium carbonates. These carbonate minerals are particularly exciting because they naturally trap and preserve organic molecules.
The ancient lake at Jezero was roughly twice the size of Lake Tahoe and may have been up to forty kilometres wide and tens of metres deep.
Perseverance has collected sample tubes from both the Margin unit and the Bright Angel mudstone formation, though the NASA-ESA Mars Sample Return mission faces uncertainty after Congress cut funding in early January 2026.
NASA Rover Discovers Ancient Beach on Mars, Transforming Our Understanding of the Red Planet
January 28, 2026
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NASA's Perseverance rover has found compelling evidence of an ancient beach at Mars's Jezero crater, revealing wave-formed shorelines and water-altered rocks that suggest the planet once had habitable conditions lasting millions of years longer than previously believed.
A Beach on Mars
NASA's Perseverance rover has made what may be its most significant discovery yet: evidence of an ancient beach on Mars. An international research team led by Imperial College London announced on January 26, 2026, that layered sandstones with rounded grains found in Jezero crater point to a shoreline where waves once lapped against the crater's inner rim roughly three and a half billion years ago.The discovery came from analysing the so-called Margin unit that lines the crater's inner edge. Scientists found that the rock began as molten material from a magma chamber or lava lake. After cooling, minerals within were transformed by circulating carbon dioxide-rich underground water, creating iron and magnesium carbonates. These carbonate minerals are particularly exciting because they naturally trap and preserve organic molecules.
Tropical Rains on Ancient Mars
Compounding this picture, separate research published in December 2025 by Purdue University identified white kaolinite clay scattered across the crater. This mineral only forms on Earth after millions of years of heavy rainfall in warm, humid climates, suggesting Mars once experienced tropical conditions for extended periods.The ancient lake at Jezero was roughly twice the size of Lake Tahoe and may have been up to forty kilometres wide and tens of metres deep.
Implications for the Search for Life
The findings significantly extend the timeline for when Mars could have supported life. The beach discovery sits beneath the Jezero river delta, indicating that calm lake conditions existed even earlier than scientists had thought. Professor Sanjeev Gupta of Imperial College London noted that subsurface hydrothermal environments like those now confirmed at Jezero are known to support microbial life on Earth.Perseverance has collected sample tubes from both the Margin unit and the Bright Angel mudstone formation, though the NASA-ESA Mars Sample Return mission faces uncertainty after Congress cut funding in early January 2026.
Published January 28, 2026 at 10:47am
