ESA Mars Express Orbiter (MRO) image: Thaumasia Planum region

Colour-coding shows the relative depth of two craters on Mars, in particular the depth of the central pits. 

The left-hand crater penetrates deeper than the right one, Arima crater. 

The ESA Mars Express Orbiter spacecraft (MEO) captured the image of Thaumasia Planum region on January 4, 2013.

Credit: ESA 

Further studies of Thaumasia Planum in Geophysical Research Letters

Nasa Mars Reconnaissance Orbiter Images