ESA: Signs of ancient flowing rivers on Mars

We see Mars as a cold, dry world, but plenty of evidence suggests that this was not always the case. Research in past years instead increasingly indicates that the planet once had a thicker, denser atmosphere that was able to lock in far greater amounts of warmth, and therefore facilitate and support the flow of liquid water on the surface below.  Continue reading:

http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Signs_of_ancient_flowing_water_on_Mars2

• Title Perspective view of ancient river valley network on Mars
• Released 21/02/2019 11:00 am
• Copyright ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
• Description This image from ESA’s Mars Express shows a valley network on Mars. This oblique perspective view was generated using a digital terrain model and Mars Express data gathered on 19 November 2018 during Mars Express orbit 18831. The ground resolution is approximately 14 m/pixel and the images are centered at 66°E/17°S. This image was created using data from the nadir and colour channels of the High Resolution Stereo Camera (HRSC). The nadir channel is aligned perpendicular to the surface of Mars, as if looking straight down at the surface.