Chapter 1
The curious carbon-12 discovery
Chapter 2
Rethinking the red planet's cycle
Chapter 3
Perseverance and the organic map
YOUR GOAL
Master of The mystery of Mars' carbon
Ch 2 · Rethinking the red planet's cycle
streetspirit The Martian Carbon Cycle
Deep in the rocks of Gale Crater's ground, the ancient carbon cycle of Mars has been found.
streetspirit The discovery of siderite confirms that ancient Mars had an active carbon cycle capable of supporting liquid water.
streetspirit In April 2025, scientists announced that Curiosity found pure iron carbonate, solving a long-standing atmospheric mystery.
Fun Fact
Martian iron rust: Mars is red because its surface is covered in iron oxide, which is literally rust from ancient water reacting with iron.
Glossary
carbon cycle (noun)
The continuous process by which carbon is exchanged between a planet's atmosphere, surface, and geological formations. Curiosity's April 2025 discovery of siderite in Gale Crater confirmed this process once operated on Mars.
The continuous process by which carbon is exchanged between a planet's atmosphere, surface, and geological formations. Curiosity's April 2025 discovery of siderite in Gale Crater confirmed this process once operated on Mars.
Quiz
What type of mineral did Curiosity find in 2025 that proved Mars had an ancient carbon cycle?
Quiz
Which instrument on Curiosity used X-ray diffraction to identify the mineral siderite in 2025?
Quiz
What major planetary shield did Mars lose about 4 billion years ago, leading to atmospheric loss?
Quiz
Why was the lack of carbonate minerals on Mars' surface long considered a mystery?