It’s easy to take for granted the detailed, almost real-time knowledge of Mars that we have at our fingertips. After all, in the not-too-distant past, Mars was largely mysterious. All we had were ground-based images of the planet. Now? Now we have daily weather reports and images of dust storms.
Mars is often referred to as “Earth’s Twin”, due to the similarities it has with our planet. They are both terrestrial planets, both have polar ice caps, and (at one time) both had viable atmospheres and liquid water on their surfaces. But beyond that, the two are quite different. And when it comes to their atmospheres and climates, Mars stands apart from Earth in some rather profound ways.