Here’s why Mars died 3.5 billion years ago. Long before it became a frozen desert, Mars had oceans, rivers, and a thick atmosphere. But when the planet’s magnetic field collapsed, the Sun’s solar wind stripped its atmosphere into space — ending Mars’ habitability forever. This short explains how a once-blue Mars transformed into the silent world we see today. 🌑 More about Mars & planetary science – How planetary magnetic fields protect atmospheres – Why Mars lost its internal dynamo – Evidence