In this VIS image, taken by the NASA - Mars Odyssey Orbiter on August, 9th, 2014, and during its 56.128th orbit around the Red Planet, we can see a very small section of Ma'adim Vallis, which is a large Outflow Channel that enters Gusev Crater from the South. Gusev Crater, as you know, has been, is and will be (probably for centuries and more), the "home" of the Mars Exploration Rover (MER) Spirit (now decommissioned).
Ma'adim Vallis is one of the largest Outflow Channels of Mars; it is about 700 Km (such as approx. 434,7 miles) long and significantly larger than Earth's Grand Canyon. It is over 20 Km (approx. 12,42 miles) wide and about 2 Km (such as approx. 1,242 miles) deep in some places.
Ma'adim Vallis runs from a Region of the Southern Lowlands - that is thought to have once contained a large group of Lakes (including Eridania Lake) - and ends up, as we wrote hereabove, within Gusev Crater, near the Martian Equator. For those Readers who are studying the "Martian Average Craters' Density", we can say that only a few - old, and and not really big - Impact Craters can be spotted in this (we repeat: extremely small) section of Ma'adim Vallis.
Latitude (centered): 18,5885° South
Longitude (centered): 177,1770° East
This image (which is an Original Mars Odyssey Orbiter b/w and Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 18703) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced and sharpened, Gamma corrected and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Odyssey Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.