The highly incised Martian gullies seen in the top image resemble gullies on Earth that are carved by liquid water. However, when the gullies are observed with the addition of mineralogical information (bottom), no evidence for alteration by water appears. The pictured area spans about 2 miles (3 kilometers) on the eastern rim of Hale Crater. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took the visible-light image. Color-coded compositional information added in the lower version comes from the same orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Color coding in light blue corresponds to surface composition of unaltered mafic material, of volcanic origin. Mafic material from the crater rim is carved and transported downslope along the gully channels. No hydrated minerals are observed within the gullies, in the data from CRISM, indicating limited interaction or no interaction of the mafic material with liquid water. These findings and related observations at about 100 other gully sites on Mars suggest that a mechanism not requiring liquid water may be responsible for carving these gullies on Mars. (Gullies on Mars are a different type of feature than seasonal dark streaks called recurring slope lineae or RSL; water in the form of hydrated salt has been identified at RSL sites.) The HiRISE image is a portion of HiRISE observation PSP_002932_1445. The lower image is from the same HiRISE observation, with a CRISM mineral map overlaid. http://photojournal.jpl.nasa.gov/catalog/PIA20763

Gullies and... Gullies? in Terra Sirenum

Gullies

Gullies

Gullies

Gullies

Gullies

Gullies

Gullies

Gullies

Gullies in Crater

Gullies in Galle

Martian Gullies

Gullied Wall

Gullied Slope

Gullied Slope

Martian Gullies

Dunes and Gullies

Gully in the North

Dunes and Gullies

Martian Gullies

Gullies and Sand

Martian Gullies

Martian Gullies

Gullies Galore!

Green Gullies

Gullies and Dunes

Gullies in Nirgal

Martian Gullies

Gullied Slope

Gullies in Crater in Hellas

Gullied Crater Wall

Gullied Trough in Noachis Terra

Gullied Crater Wall

High-resolution View of Gullies

Mid-latitude Gully Features

Gullies on Gorgonum Chaos Mesas

Gully Apron in Crater

Gullies With Bright Material

Gullied Crater Wall

South Hemisphere Gullies

Russell Dune Gullies

Defrosting Gully Aprons

Northern Hemisphere Gullies with Layers

Gullies in Wirtz Crater

Russell Dune Gullies

South Polar Pit Gullies

A Gullied Crater Wall

Mid-Latitude Gullies

Bi-level Gullies

Gullies in Sirenum Terra, Mars

Multiple-Event Gully

Small Gullied Crater

Terra Sirenum Gullies

Gullies on Martian Crater MOC

Noachis Pit Crater Gullies

South Mid-latitude Gullies

Gullied Martian Slope

Gullies in Terraced Crater Wall

Gullies in Terra Sirenum

Gullies and Ice-rich Material

Gullies in Crater Wall

Crater Wall With Gullies

Gullies in Crater Wall

Gullies on the Exterior Wall of a Crater

Gullies and Arcuate Ridges

Russell Dune Gullies

Gullied Trough Wall

This MOC image shows gullies and cracked and stressed gully apron deposits in a south mid-latitude crater. Gullies can also be seen in the deep shadow on the north wall of the crater

Craters are most often the site of gully formation on Mars. Mega-gullies are also found on the southwestern parts of Vallis Marineris, and in this image from NASA 2001 Mars Odyssey spacecraft, on hills east of Argyre Planitia.

Gullies occur on the rim of this northern plains crater

This MOC image shows gullies on the wall of a martian south mid-latitude impact crater. The channels in each gully head beneath an eroding overhang of layered rock

Multiple gullies dissect the rim of an unnamed crater located in Terra Sirenum. Towards the bottom of the image several small gullies are visible located on the rim of an older crater. Orbit Number: 75238 Latitude: -45.5986 Longitude: 225.72 Instrument: VIS Captured: 2018-11-30 08:47 https://photojournal.jpl.nasa.gov/catalog/PIA23015

Gullies in a Crater Wall in Newton Basin:

MSIP: Gullies in Craters in Noachis Terra

Sharp View of Gullies in Southern Winter

Gullies in Trough near Gorgonum Chaos

Gullies with Characteristics of Water-Carved Channels

Gullies and Layers in Crater Wall in Newton

Evidence of Multiple Episodes of Gully Formation

Solar Storms, Devils, Dunes, and Gullies

New Gullies on Martian Sand Dune

Gullies and Dunes in a Crater in Newton Basin

Gullies and Streaks on Crater wall Kaiser

The gullies at the top of the image captured by NASA 2001 Mars Odyssey spacecraft occur on the rim of an unnamed crater on the larger rim of the Argyre Basin. It has been postulated that this type of gully may form due to the melting of a snow/ice cover

Small gullies mark the rim of this unnamed crater in Utopia Planitia in this image from NASA Mars Odyssey.

This rim of this unnamed crater in Tempe Terra has been modified by the formation of numerous gullies

NASA Mars Global Surveyor image shows a suite of south mid-latitude gullies on a crater wall. Gullies such as these may have formed by runoff of liquid water.

This image taken by NASA Mars Reconnaissance Orbiter shows gullies in a semi-circular trough in Noachis Terra. The gullies are observed to face all directions.

This MOC image shows a group of gullies formed on the equator-facing wall of a north mid-latitude crater. Gullies such as these might have formed from the erosive forces of liquid water

The gullies in this image of Gali Crater occur on the northfacing/sunfacing slope

NASA Mars Reconnaissance Orbiter observes a group of small gullies along a rock layer on the south wall of Liu Hsin Crater. At the foot of the gullies fans of granular sediment have been deposited downhill from the gully formation. Nearby, there are much larger gullies. By comparing the gullies that are just 20 kilometers away, we may be able to determine the factors that affect their size. Liu Hsin (also spelled Xin) was a Chinese astronomer, historian, and editor during the Western Han Dynasty (206 BCE to 9 CE) and then the Xin Dynasty (9 to 23 CE). This caption is based in part on a public target suggestion from HiWish. (Note: the header image is non map-projected, so approximate north is down). http://photojournal.jpl.nasa.gov/catalog/PIA19175

Gullies are commonly found in the Martian mid-latitudes, particularly in the Southern Hemisphere. However, they are rare in the deepest parts of the massive Hellas impact basin. One likely reason for this is that gullies are found on steep slopes, which seem to be less common in Hellas. For this image, HiRISE targeted a relatively fresh crater where previous images from the MRO Context Camera appeared to show gullies. This high-resolution look confirms the gullies and will allow scientists to compare them in detail with gullies elsewhere on the planet. https://photojournal.jpl.nasa.gov/catalog/PIA26329

This image captured by NASA 2001 Mars Odyssey spacecraft shows gullies on the northern face of one of the large depressions that mark the inner rim of Asimov Crater.

Several gullies of different sizes in this image from NASA Mars Odyssey spacecraft are located on the southern rim of this unnamed crater in Terra Cimmeria.

Multiple gullies dissect the rim of this unnamed crater in Terra Cimmeria. Orbit Number: 74480 Latitude: -49.7019 Longitude: 140.533 Instrument: VIS Captured: 2018-09-28 22:24 https://photojournal.jpl.nasa.gov/catalog/PIA22850

HiRISE has been operating since 2006, and lately many of our observations of gullies are repeat images designed to study changes. However, we are also collecting data over gullies never before seen at this resolution, to study their morphology and allow us to look for changes in the future. This is the first HiRISE look at a cluster of gullies that appear modified or degraded—the gully fans have ripples and ridges that have formed since the last major gully activity, suggesting that they don't change very often, but we won't know for sure unless we look! https://photojournal.jpl.nasa.gov/catalog/PIA23666

This image captured by NASA Mars Odyssey shows parts of two giant gully that are located on the southern side of Ius Chasma. Ius Chasma has the largest number of mega gullies of any of the chasmata that make up Valles Marineris.

This NASA Mars Reconnaissance Orbiter shows many channels on a scarp in the Hellas impact basin. On Earth we would call these gullies. Some larger channels on Mars that are sometimes called gullies are big enough to be called ravines on Earth.

This scene shows gullies superposed on the inner walls of four large craters. Most of these gullies, imaged by NASA Mars Odyssey spacecraft, appear to emanate from one or two specific layers along the inner crater entire circumference.