The above picture is not an artists rendering. It’s an actual stereoscopic photograph of the north pole of Mars. What it shows is some of the most compelling evidence to date that Mars is a much different place than we thought just a short year ago.

The picture shows part of the Martian ice cap. There’s also strong evidence (the darker shaded areas) of relatively recent volcanic activity and what scientists call “fluvial” flows, which could be glacier activity.

What has scientists excited is the fact that the evidence points to volcanic activity on Mars within the last 20 million (and perhaps as recently as 2.5 million) years. That’s a relative blink of the eye in cosmic terms. Previously, it was thought that volcanic activity had ceased on Mars as long as several hundred million years ago.

The volcanic activity triggered a melting that caused water to once again run on Mars, maybe for the last time. The $64,ooo question being asked today is whether or not it’s possible Mars is still geologically active. Such a finding would call into question most assumptions we have about Mars being a “dead” planet.

The image above is Kasei Valles, one of the largest outflow channels on Mars, and contains a lot of evidence for glacial and fluvial activity over much of the planet’s history.

The scour marks in the valley, shown in the image on the left, are most likely due to glacial erosion than by water erosion. This is contrary to what was previously thought.

The glacier that caused this valley was fed by water from the Echus Chasma region, which was driven out from underneath the surface by volcanic activity. Water was released by heating from volcanic activity in the channel floor as relatively recently as 20 million years ago.

What all this adds up to is that Mars is a much more interesting place than scientists could have imagined. Thanks to the two NASA rovers Spirit and Oppotunity as well as the ESA probe Mars Express, our knowledge of the red planet has taken a dramatic leap in the last year and only whets our appetite for further discoveries.

Pictures courtesy of the European Space Agency