ISRO’s Mars Orbiter: Olympus Mons, Tharsis Bulge and Valles Marineris trio of volcanoes

Olympus Mons, Tharsis Bulge trio of volcanoes, and Valles Marineris from ISRO’s Mars Orbiter Mission. 

Note the clouds and south polar ice cap. 

Credit: ISRO

India's Mars Orbiter Mission (MOM) has delivered another sweet treat – a stunning view of our Solar System's largest volcano and the largest canyon.

Just days ago, MOM captured a new global image of the Red Planet dominated by Olympus Mons and Valles Marineris, which is the largest known volcano and the largest known canyon in the Solar System, respectively.

Situated right in between lies a vast volcanic plateau holding a trio of huge volcanoes comprising the Tharsis Bulge: Arsia Mons, Pavonis Mons, and Ascraeus Mons. All three are shield volcanoes.

To give an idea of its enormity, Olympus Mons stands about three times taller than Mount Everest and is about the size of Arizona.

Olympus Mons is located in Mars' western hemisphere and measures 624 kilometers (374 miles) in diameter, 25 km (16 mi) high, and is rimmed by a 6 km (4 mi) high scarp.

Valles Marineris is often called the "Grand Canyon of Mars." It spans about as wide as the entire United States.

The Indian Space Research Organization (ISRO), India's space agency which designed and developed the orbiter released the image on Oct. 17, barely two days ahead of the planet's and spacecrafts' extremely close encounter with comet Siding Spring.

Olympus Mons from Mars orbit compared to the state of Arizona. 

Credit: NASA

By the way, a relieved ISRO tweeted MOM's survival of her close shave with the once-in-a-lifetime cometary passage with gusto, soon after the swingby:
"Phew! Experience of a lifetime. Watched the #MarsComet #SidingSpring whizzing past the planet. I'm in my orbit, safe and sound."

The new global image was taken by the tri-color camera as MOM swooped around the Red Planet in a highly elliptical orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km, according to ISRO.

To date ISRO has released four global images of the Red Planet, including a 3-D view.

Olympus Mons, the Tharsis Bulge, and Valles Marineris are near the equator.

Valles Marineris stretches over 4,000 km (2,500 mi) across the Red Planet, is as much as 600 km wide, and measures as much as 7 kilometers (4 mi) deep.

Global Mosaic of Mars Centered on Valles Marineris from NASA’s Viking 1 orbiter. 

Credit: NASA

Here's a comparison view of the region taken by NASA's Viking 1 orbiter in the 1970s.

MOM is India's first deep space voyager to explore beyond the confines of her home planet's influence and successfully arrived at the Red Planet only one month ago after the "history creating" orbital insertion maneuver on Sept. 23/24 following a ten month journey.

The $73 million MOM mission is expected to last at least six months.

ISRO’s Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74,500 km on Sept. 28, 2014. 

Credit: ISRO

MOM's success follows closely on the heels of NASA's MAVEN orbiter which also successfully achieved orbit barely two days earlier on Sept. 21 and could last 10 years or more.

With MOM's arrival, India became the newest member of an elite club of only four entities that have launched probes that successfully investigated Mars, following the Soviet Union, the United States, and the European Space Agency (ESA).

NASA MRO: Lava, not water, formed canyons on Mars

The Grand Canyon of Mars – Valles Marineris. Credit: NASA,Viking Project,USGS, CC BY

The canyon-like scars which line Mars' crust are seen by many as evidence for liquid water but a study now suggests that a different kind of fluid, one much less hospitable to life, may actually have carved these features.

On Mars, the most striking topography occurs around the equator. The planet's low latitudes are dominated by the Tharsis plateau, which hosts several towering volcanoes.


Not far off sits the solar system's largest, Olympus Mons. Near the Eastern fringe, however, things start to get deep.

There the land dives into a winding maze of valleys and river-like "outflow channels", the former including the 4000km-long Valles Marineris, the "Grand Canyon" of Mars, which exceeds its terrestrial namesake in every dimension.

These great gouges are widely thought to have been formed, at least in part, by flowing water. But according to recently published research, they could have had a very different genesis, linked to the volcanoes to the West.

Explosive erosion
A paper by Giovanni Leone of the Swiss Federal Institute of Technology, published in the Journal of Volcanology and Geothermal Research, suggests that the martian valleys and outflow channels were in fact formed mostly by lava flows, which erupted from the Tharsis plateau in the planet's distant past.

To draw this conclusion, Leone scrutinised thousands of images from NASA's Mars Reconnaissance Orbiter (MRO) spacecraft, which has been orbiting the planet since 2006.

This allowed him to map the floors of the equatorial valleys and outflow channels at an extremely high resolution of up to 25cm per pixel.

These images appear to show extensive lava flows draping the floors of many of the valleys and channels. Around 90% of the floors look to be covered either by lava or by lava-related landslides.

Valles Marineris 

Credit: G. Neukum/ESA/Mars Express/DLR, CC BY

The morphology of the lava flows Leone encountered suggest that the lava actually incised the valleys and channels in the first place.

The MRO images seem to show that channels formed by the freshly erupted lava were later deepened and widened by the passage of liquid rock.

This type of erosion, Leone argues, can explain the existence of the valleys and outflow channels without the need to invoke significant amounts of liquid water.

The valleys and outflow channels are believed to be many billion years old. Leone believes the lava would have been emitted by now-vanished volcanoes somewhere on the Tharsis plateau, forerunners of the region's (relatively juvenile) modern volcanoes.

Leone believes that every stage of this volcanic erosion process is visible in the MRO images. The first stage, he concludes, can be seen in the locations closest to today's Tharsis volcanoes, at the western end of Valles Marineris. Here lava tunnels seem to have collapsed, forming "pit chains" – long curvilinear depressions in the crust.

Further east, where the terrain deepens, the pit chains seem to have been further eroded, by the injection of yet more lava, into more extensive channels – first into "fossae" and later into larger "chasmata".

The MRO images showed relatively little evidence for the past presence of liquid water in the valleys and outflow channels, which can be inferred by the presence of "light toned deposits" in the images. This, Leone believes, adds further weight to the theory that these features are igneous in origin.

ESA’s Mars Express Image: MARS Olympus Mons by the High Resolution Stereo Camera

A portion of the southeastern flank of Olympus Mons as imaged by the High Resolution Stereo Camera on ESA’s Mars Express on 21 January 2013 (orbit 11524), with a ground resolution of approximately 17 m per pixel. 

The image centre is located at approximately 14°N / 229°E. North is to the right. 

The image highlights the stark contrast between the hundreds of narrow, individual lava flows on the flanks of the volcano, and the smooth lava plains that surround it. 

Credit: ESA/DLR/FU Berlin (G. Neukum)

Hundreds of individual lava flows are seen frozen in time on the flanks of Olympus Mons, the largest volcano in the Solar System.

The images, taken on 21 January 2013 by ESA's Mars Express, focus on the southeast segment of the giant volcano, which towers some 22 km above the surrounding plains. This is more than double the height of Mauna Kea, the tallest volcano on Earth at 10 km, when measured from its oceanic base to summit.

Like Mauna Kea, Olympus Mons is a shield volcano, with gently sloping sides that extend outwards at low angles. But unlike other shield volcanoes, it has an abrupt cliff edge, or scarp, separating it from the surrounding plains.

The scarp circles the entire volcano, in places reaching 9 km high. It was likely formed during a number of catastrophic landslides on the flanks of the volcano, during which the resulting debris was transported several hundred kilometres beyond the extent of these images.

Lava flows cover the base of the volcano, punctuated by a handful of pointy and flat-topped blocks that were either rotated or uplifted during the collapse. The transition from the towering heights of the volcano down onto the flat lava plain at the base of the scarp can be easily seen in the colour-coded topography image.

Lava once flowed down the flanks of the Olympus Mons volcano, spilling out onto the surrounding plains.

Here, the paths of numerous individual lava flows can be seen curving around natural obstacles and cascading like waterfalls over cliff edges. 

Random pointed and flat-topped blocks protrude from the flank edges, rotated or uplifted as the sides of the volcano collapsed. 

Only a few very faint traces of ancient lava channels can be seen in the surrounding plain, which was flooded by a later outpouring of lava.

The image was taken by the High Resolution Stereo Camera on ESA’s Mars Express on 21 January 2013 (orbit 11524), with a ground resolution of approximately 17 m per pixel. 

The image centre is located at approximately 14°N / 229°E. 

Credit: ESA/DLR/FU Berlin (G. Neukum)

In the leading colour image and perspective views, extensive networks of narrow, overlapping lava flows are proof of an extremely active volcanic past.

The lava, long since solidified, once spilled down the natural contours of the volcano, spreading out into broad fans as it reached the scarp and plains below.

Flows that ended before reaching the scarp did so with rounded tongues, as the lava cooled and crept to a stop.

Some lava flows are bounded by steep channel walls, while others were contained in lava tubes. Zooming in to the top left portion of the flank in the leading image reveals one example of an ancient lava tube, its winding track partially exposed in channel segments where the roof of the tunnel has since collapsed.

The chaotic lava flows on the flanks provide a stark contrast to the smooth plains seen surrounding the volcano.

ESA Mars Express Image: Landslides and lava flows at Olympus Mons on Mars

ESA’s Mars Express imaged the Sulci Gordii region of Mars with its High Resolution Stereo Camera on 23 January 2013 (orbit 11531), with a ground resolution of about 31 m per pixel. 

Sulci Gordii lies at approximately 17°N / 234°E, about 200 km east of Olympus Mons. 

Credit: ESA/DLR/FU Berlin (G. Neukum)

Giant landslides, lava flows and tectonic forces are behind this dynamic scene captured recently by ESA's Mars Express of a region scarred by the Solar System's largest volcano, Olympus Mons.

The image was taken on 23 January by the spacecraft's high-resolution stereo camera, and focuses on a region known as Sulci Gordii, which lies about 200 km east of Olympus Mons.

Sulci Gordii is an 'aureole' deposit – from the Latin for 'circle of light' – and is one of many that form a broken ring around the giant volcano, as hinted at in the context map.

Olympus Mons

The aureoles tell the story of the catastrophic collapse of the lower flanks of Olympus Mons in its distant past. Today, it stands with steep cliff edges that rise 2 km above the surrounding plains.

The collapse was brought about by weakening in the rocks supporting the volcanic edifice, perhaps influenced by subsurface water. During the collapse, rocky debris slid down and out over hundreds of kilometres of the surrounding volcanic plains, giving rise to the rough-textured aureole seen today.

Similar avalanches of debris are also seen surrounding some volcanoes on Earth, including Mauna Loa in Hawaii, which, like Olympus Mons, is a smooth-sided 'shield' volcano built up from successive lava flows.

Sulci Gordii was imaged by the High Resolution Stereo Camera on ESA’s Mars Express on 23 January 2013 (orbit 11531). 

Sulci Gordii lies at approximately 17°N / 234°E, about 200 km east of Olympus Mons. 

Sulci Gordii is one of many similar features that form a broken ring around the volcano, formed during giant collapse and landslide events on the flanks of Olympus Mons. 

Credit: NASA MGS MOLA Science Team

The smooth plains surrounding Sulci Gordii suggest that the massive landslide was later partially buried by lava flows.

The characteristic corrugated appearance of the 'sulci' – a geological term used to describe roughly parallel hills and valleys on Mars – likely resulted during the landslide as material slid away from the volcano and became compressed or pulled apart as it travelled across the surface.

Over time, erosion of weaker material between the peaks accentuated this effect.

The corrugated effect is best seen in the close-up perspective views. Zooming in on these images reveals that the hills and ridges are also covered by fine wind-blown dust, and that many small-scale landslides have occurred down the sides of the valleys between them.

Similarly, on close inspection of the smooth plains, subtle ripples in the martian dust blanket can be seen. Here, thin undulating dunes have been whipped into shape by the prevailing wind.

Close-up of the ‘sulci’ features that define Sulci Gordii. Sulci are roughly parallel sets of ridges and valleys likely formed through tectonic and erosional processes. 

A prominent fault line extends along the left side of the image, while smooth lava plains overlay parts of the sulci. 

Credit: ESA/DLR/FU Berlin (G. Neukum)

Numerous sinuous channels and jagged fracture networks also crisscross the scene, in particular at the southern (left) end of the main image and in close-up in the perspective view above.

The channels range in length from around 50 km to 300 km and were probably widened by short-lived lava flows, or perhaps even by water.

An impressive sight on the left side of the perspective view is a sinuous channel that is suddenly truncated by a tectonic fault. Another channel running across the centre foreground clearly has a complex fracturing history.

In rougher terrain towards the south (top centre-right of the main image), tectonic forces have torn apart the martian crust, most clearly visible in the colour-coded topography map.

By studying complex regions like this – and by comparing them to similar examples here on Earth – planetary scientists learn more about the geological processes that dominated ancient Mars, when it was an active planet.

Just as on Earth, the scene at Sulci Gordii tells us that volcanoes can suffer dramatic collapses that transport vast quantities of material across hundreds of kilometres, where it is subsequently sculpted by wind, water and tectonic forces.