4.3 billion years ago, Mars had a deep blue ocean covering 19% of its surface — more water than Earth's Arctic Ocean. Today it's a frozen desert with less than 1% of Earth's atmospheric pressure. What happened wasn't a slow fade. It was a planetary murder mystery — and thanks to NASA's MAVEN mission and the Curiosity rover, we now know almost exactly how the killer did it.

In this episode we dig into the isotope evidence that proves 87% of Mars's water is gone, the solar wind sputtering mechanism that's still stripping the atmosphere today, a 2008 experiment that caught Earth and Mars getting hit by the same solar wind gust at the same time, the strange paradox where a weak magnetic field is actually worse than no field at all, and the newly discovered "Zwan Wolf Effect", a defense mechanism nobody knew Mars had until a massive solar storm  ...