Features of Mars
Sinusoidal Map of Mars
This image is a sinusoidal map of Mars. It was generated from a
digitized airbrush map and was color-coded to represent elevation.
This image is a simple cylindrical map of Mars. The color
represents elevation and ranges from -4 kilometers to 27 kilometers.
This image is a mosaic of the Schiaparelli hemisphere of Mars.
The center of this image is near the impact crater Schiaparelli, 450 kilometers
(280 miles) in diameter. The dark streaks with bright margins emanating from craters
in the Oxie Palus region, upper left of image, are caused by erosion and/or deposition by
the wind. Bright white areas to the south, including the Hellas impact basin at
extreme lower right, are covered by carbon dioxide frost.
This image is a mosaic of the Valles Marineris hemisphere of Mars. It
is a view similar to that which one would see from a spacecraft. The center of the scene
shows the entire Valles Marineris canyon system, more than 3,000 kilometers (1,860 miles)
long and up to 8 kilometers (5 miles) deep, extending from Noctis Labyrinthus, the arcuate
system of graben to the west, to the chaotic terrain to the east. Many huge ancient
river channels begin from the chaotic terrain and north-central canyons and run north.
Many of the channels flowed into a basin called Acidalia Planitia, which is the
dark area in the extreme north of this picture. The three Tharsis volcanoes (dark
red spots), each about 25 kilometers (16 miles) high, are visible to the west. Very
ancient terrain covered by many impact craters lies to the south of Valles Marineris.
Central Candor Chasm - Oblique View
This image shows part of Candor Chasm in Valles Marineris. It is
centered at Latitude -5.0, Longitude 70.0. The view is from the north looking into
the chasm. Candor Chasm's geomorphology is complex, shaped by tectonics, mass
wasting, wind, and perhaps by water and volcanism.
West Candor Chasm (Enhanced Color)
This picture (centered at latitude 4° S, longitude 76° W) shows areas
of central Valles Marineris, including Candor Chasm (lower left), Ophir Chasm (lower
right), and Hebes Chasm (upper right). Complex layered deposits in the canyons may have
been deposited in lakes, and if so, are of great interest for future searches for fossil
life on Mars. The pinkish deposits in Candor Chasm may be due to hydrothermal
alterations and the production of crystalline ferric oxides.
Landslide in Valles Marineris
Although Valles Marineris originated as a tectonic structure, it has
been modified by other processes. This image shows a close-up view of a landslide on
the south wall of Valles Marineris. This landslide partially removed the rim of the
crater that is on the plateau adjacent to Valles Marineris. Note the texture of the
landslide deposit where it flowed across the floor of Valles Marineris. Several
distinct layers can be seen in the walls of the trough. These layers may be regions
of distinct chemical composition or mechanical properties in the Martian crust.
HST 3 Views of Mars at Opposition
These Hubble Space Telescope views provide the most detailed complete
global coverage of the Red Planet ever seen from Earth. The pictures were taken on
February 25, 1995, when Mars was at a distance of 103 million kilometers (65 million
miles). To the surprise of researchers, Mars is cloudier than seen in previous
years. This means the planet is cooler and drier, because water vapor in the
atmosphere freezes out to form ice-crystal clouds. The three images show the
Tharsis, Valles Marineris and Syrtis Major regions.
Springtime on Mars: Hubble's Best View
of the Red Planet
This NASA Hubble Space Telescope view of Mars is the clearest picture
ever taken from Earth, surpassed only by close-up shots sent back by visiting space
probes. The picture was taken on February 25, 1995, when Mars was at a distance of
approximately 103 million kilometers (65 million miles) from Earth.
Because it is spring in Mars' northern hemisphere, much of the
carbon dioxide frost around the permanent water-ice cap has sublimated, and the cap has
receded to its core of solid water-ice several hundred miles across. The abundance
of wispy white clouds indicates that the atmosphere is cooler than seen by visiting space
probes in the 1970s. Morning clouds appear along the planet's western (left) limb.
These form overnight when Martian temperatures plunge and water in the atmosphere
freezes out to form ice-crystal clouds. Towering 25 kilometers (16 miles) above the
surrounding plains, volcano Ascraeus Mons pokes above the cloud deck near the western or
limb. Valles Marineris is in the lower left.
Outflow Source of Channel Ravi Vallis
This image of the head of Ravi Vallis shows a 300-kilometer (186-mile)
long portion of a channel. Like many other channels that empty into the northern
plains of Mars, Ravi Vallis orginates in a region of collapsed and disrupted
("chaotic") terrain within the planet's older, cratered highlands.
Structures in these channels indicate that they were carved by liquid water moving
at high flow rates. The abrupt beginning of the channel, with no apparent
tributaries, suggests that the water was released under great pressure from beneath a
confining layer of frozen ground. As this water was released and flowed away, the
overlying surface collapsed, producing the disruption and subsidence shown here.
Three such regions of chaotic collapsed material are seen in this image, connected
by a channel whose floor was scoured by the flowing water. The flow in this channel
was from west to east. This channel ultimately links up with a system of channels
that flowed northward into Chryse Basin.
The water that carved the channels to the north and east of the Valles
Marineris canyon system had tremendous erosive power. One consequence of this erosion was
the formation of streamlined islands where the water encountered obstacles along its path.
This image shows two streamlined islands that formed as the water was diverted by
two 8-10 kilometer (5-6 mile) diameter craters lying near the mouth of Ares Vallis in
Chryse Planitia. The water flowed from south to north (bottom to top of the image).
The height of the scarp surrounding the upper island is about 400 meters (1,300
feet), while the scarp surrounding the southern island is about 600 meters (2,000 feet)
Unlike the features shown in the above two images, many systems on Mars
do not show evidence of catastrophic flooding. Instead, they show a resemblance to
drainage systems on Earth, where water acts at slow rates over long periods of time.
As on Earth, the channels shown here merge together to form larger channels.
However, these valley networks are less developed than typical
terrestrial drainage systems, with the Martian examples lacking small-scale streams
feeding into the larger valleys. Because of the absence of small-scale streams in
the Martian valley networks, it is thought that the valleys were carved primarily by
ground water flow rather than by runoff of rain. Although liquid water is currently
unstable on the surface of Mars, theoretical studies indicate that flowing groundwater
might be able to form valley networks if the water flowed beneath a protective cover of
ice. Alternatively, because the valley networks are confined to relatively old
regions of Mars, their presence may indicate that Mars once possessed a warmer and wetter
climate in its early history.
This image shows several dune types which are found in the north
circumpolar dunefield. This thumnail image shows a section of transverse dunes.
The full image has a field of traverse dunes on the left and barchan dunes on the
right with a transition zone inbetween. Transverse dunes are oriented perpendicular to the
prevailing wind direction. They are long and linear, and frequently join their
neighbor in a low-angle "Y" junction. Barchan dunes are crescent-shaped
mounds with downwind-pointing horns. These dunes are comparable in size to the
largest dunes found on the Earth.
Local Dust Storm
Local dust storms are relatively common on Mars. They tend to
occur in areas of high topographic and/or high thermal gradients (usually near the polar
caps), where surface winds would be strongest. This storm is several hundreds of
kilometers in extent and is located near the edge of the south polar cap. Some local
storms grow larger, others die out.
Face on Mars
This image shows the Face on Mars that imaginative writers have
cited as evidence for intelligent life on Mars. It is more likely that this hill, in
the northern plains, has been eroded by the wind to give it a face like appearance.