Tag Archives: Mars Odyssey

Mars Odyssey looks down at Curiosity

Gale Crater

The Mars Odyssey team today released an image the spacecraft took of Gale Crater on January 16, 2018. This image, reduced in resolution, is posted on the right and captures the entire region that the rover Curiosity has been traversing for the past six years. If you click on the image you can view the full resolution original.

I have placed Curiosity’s full route since its landing on this image so that we can see where the rover has been. The actual peak of Mount Sharp is a considerable distance to the south and is not visible in this image. (For the full context of the crater and Curiosity’s travels see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater)

The river-like flow feature cutting through the north rim is called Peace Vallis. Scientists think this was formed by water flowing into the crater when the climate of Mars was wetter and there was a lake inside the crater floor.

You can get another perspective of this same view by looking at the panorama looking north that Curiosity took once it climbed up onto Vera Rubin Ridge.

I have said this before, but this Mars Odyssey image once again illustrates how little of Mars we have so far seen. Curiosity has barely begun its climb into the foothills of Mount Sharp. The mile-high mountains that form the rim of Gale Crater are far away, and will not be walked for probably generations. I do not expect any space probe or explorer to enter Peace Vallis for at least a hundred years, since there are so many other places on Mars to visit and Gale Crater has already gotten its first reconnaissance by Curiosity.

The image also gives as a view of Curiosity’s future travels. Based on this October 3, 2016 press release, Curiosity will eventually head into the mouth of the large canyon directly to the south of its present position. Whether the mission will continue up this canyon wash, using it as the route up Mount Sharp, will depend on many things, including the roughness of the terrain in that canyon and the simple question of whether the rover will be able to operate that long.

If it does, the views then from inside that canyon should be quite breathtaking.


Exploring Arsia Mons

Master index

In November over a period of two weeks the Mars Odyssey team posted ten images of Pavonis Mons, the smallest of the aligned three giant volcanoes just to the east of Olympus Mons, the largest known volcano in the solar system. I then made all of those images available in a single link, with some analysis.

They have now done the same thing for the southernmost (and possibly the most interesting) of those three aligned volcanoes, Arsia Mons. From the first image below:

Arsia Mons is the southernmost of the Tharsis volcanoes. It is 270 miles (450km) in diameter, almost 12 miles (20km) high, and the summit caldera is 72 miles (120km) wide. For comparison, the largest volcano on Earth is Mauna Loa. From its base on the sea floor, Mauna Loa measures only 6.3 miles high and 75 miles in diameter. A large volcanic crater known as a caldera is located at the summit of all of the Tharsis volcanoes. These calderas are produced by massive volcanic explosions and collapse. The Arsia Mons summit caldera is larger than many volcanoes on Earth.

In other words, you could fit almost all of Mauna Loa entirely within the caldera of Arsia Mons.

The image on the right above is the master index, annotated by me to show the area covered by each image. The images can accessed individually below.
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Exploring one of Mars’ giant volcanoes

Master index

For the past two weeks JPL’s image site has been releasing a string of images taken by Mars Odyssey of the smallest of Mars’ four giant volcanoes.

Pavonis Mons is one of the three aligned Tharsis Volcanoes. The four Tharsis volcanoes are Ascreaus Mons, Pavonis Mons, Arsia Mons, and Olympus Mars. All four are shield type volcanoes. Shield volcanoes are formed by lava flows originating near or at the summit, building up layers upon layers of lava. The Hawaiian islands on Earth are shield volcanoes. The three aligned volcanoes are located along a topographic rise in the Tharsis region. Along this trend there are increased tectonic features and additional lava flows. Pavonis Mons is the smallest of the four volcanoes, rising 14km above the mean Mars surface level with a width of 375km. It has a complex summit caldera, with the smallest caldera deeper than the larger caldera. Like most shield volcanoes the surface has a low profile. In the case of Pavonis Mons the average slope is only 4 degrees.

The image on the right is the context image, annotated by me to show where all these images were taken. The images can accessed individually below.

Each of these images has some interesting geological features, such as collapses, lava tubes, faults, and flow features. Meanwhile, the central calderas are remarkable smooth, with only a few craters indicating their relatively young age.

The most fascinating geological fact gleaned from these images is that they reveal a larger geological trend that runs through all of the three aligned giant volcanoes to the east of Olympus Mons.

The linear and sinuous features mark the locations of lava tubes and graben that occur on both sides of the volcano along a regional trend that passes thru Pavonis Mons, Ascreaus Mons (to the north), and Arsia Mons (to the south).

This trend probably also indicates the fundamental geology that caused all three volcanoes to align as they have.

Arsia Mons is of particular interest in that water clouds form periodically above its western slope, where there is also evidence of past glaciation. Scientists strongly suspect that there is a lot of water ice trapped underground here, possibly inside the many lava tubes that meander down its slopes. These facts also suggest that this might be one of the first places humans go to live, when they finally go to live on Mars.


Mars Odyssey makes its first observations of Phobos

Sixteen years after entering Mars orbit Mars Odyssey finally made its first observations of the Martian moon Phobos last week.

Since Odyssey began orbiting the Red Planet in 2001, THEMIS has provided compositional and thermal-properties information from all over Mars, but never before imaged either Martian moon. The Sept. 29 observation was completed to validate that the spacecraft could safely do so, as the start of a possible series of observations of Phobos and Deimos in coming months.

In normal operating mode, Odyssey keeps the THEMIS camera pointed straight down as the spacecraft orbits Mars. In 2014, the spacecraft team at Lockheed Martin Space Systems, Denver; and NASA’s Jet Propulsion Laboratory, Pasadena, California; and the THEMIS team at Arizona State University, Tempe, developed procedures to rotate the spacecraft for upward-looking imaging of a comet passing near Mars. The teams have adapted those procedures for imaging the Martian moons.

The data from this particular observation is less significant than the fact that the spacecraft can now do it. Expect some new results about the Martian moons in the coming months.


Water ice found near Martian equator

A review of old Mars Odyssey data has revealed the presence on Mars of water ice near the planet’s equator.

The article makes a big deal about the importance of this discovery for the possibility of past or even present life on Mars. I say that its real importance relates to future colonists, and cannot be understated.

I should add one caveat: The resolution of the data is not great, 290 kilometers, which leaves a lot of room for error.


An avalanche pile on Mars

Avalanche pile on Mars

Cool image time! The Mars Odyssey science team has released this very interesting image, cropped on the right, of an avalanche debris pile formed when the large section of cliff on the left broke off and collapsed into the valley below. The valley is called Tiu Valles and is located close to Mars’ equator.

The wide spread of the debris is an indication of several things. For one, it illustrates the light Martian gravity, which allowed the debris to flow much farther than it would have on Earth.

For another, the spread of the debris pile suggests to me that the material that fell was very crumbly. It might have been able to hold together as a cliff for a long time, but when it collapsed the material broke apart almost like sand. Think of a sand castle you might have built as a kid on the beach. With a little moisture you can pack the sand to form solid shapes, but if your shape breaks apart the sand falls not as large blocks but as crumbly soft and loose sand. That is what appears to have happened here.

There is also the suggestion to me that water might have been involved somehow in this collapse. I am not a geologist so this speculation on my part is very unreliable. However, the shape of the debris pile suggests a liquid flow. The flow itself wasn’t liquid, but liquid might have somehow been involved in causing this geological event. We would need a geologist however to clarify these guesses on my part.


Wind erosion on Mars

Wind erosion on Mars

Cool image time! The image on the right, cropped to show here, was taken by Mars Odyssey. While the features shown appear at first glance to have been formed by water, they have instead in etched by wind.

The narrow ridge/valley system seen in this image are a feature called yardangs. Yardangs form when unidirectional winds blow across poorly cemented materials. Multiple yardang directions can indicate changes in regional wind regimes.

The release does not say what direction the wind was blowing, but if I had to guess, I’d say from south to north.


Vast Martian dune fields

Olympia Undae dune field

Cool image time! In the past few days the Themis camera on Mars Odyssey has taken two pictures of the vast Olympia Undae dune field near Mars’s north pole. The image to the right is only a cropped, lower resolution section of one of those images.

The image was taken during the summer, so most of the winter frost has evaporated away. Unfortunately, the website does not provide a scale, though they say the full images each cover about 12 by 43 miles of territory. Yet, both images capture only very tiny portions of the dune field, which apparently goes on and on for many hundreds of miles in all directions, looking exactly the same wherever you look.

Just imagine trying to travel though this area. It is the epitome of a trackless waste. And without some form of GPS system getting lost forever would be incredibly easy.


Curiosity is out of safe mode and will be resuming full science operations by next week.

Curiosity is out of safe mode and will be resuming full science operations by next week.

It is imperative that the engineers clear up these computer problems now, as communications with the rover will be limited in April because the sun will be in the way.

Transmissions from Earth to the orbiters [Mars Odyssey and Mars Reconnaissance Orbiter] will be suspended while Mars and the sun are two degrees or less apart in the sky, from April 9 to 26, with restricted commanding during additional days before and after. Both orbiters will continue science observations on a reduced basis compared to usual operations. Both will receive and record data from the rovers. Odyssey will continue transmissions Earthward throughout April, although engineers anticipate some data dropouts, and the recorded data will be retransmitted later.

The Mars Reconnaissance Orbiter will go into a record-only mode on April 4. “For the entire conjunction period, we’ll just be storing data on board,” said Deputy Mission Manager Reid Thomas of JPL. He anticipates that the orbiter could have about 40 gigabits of data from its own science instruments and about 12 gigabits of data from Curiosity accumulated for sending to Earth around May 1.

NASA’s Mars Exploration Rover Opportunity is approaching its fifth solar conjunction. Its team will send no commands between April 9 and April 26. The rover will continue science activities using a long-term set of commands to be sent beforehand.


Engineers have successfully tested a spare reaction wheel on Mars Odyssey in their effort to bring the spacecraft back into full operation.

Engineers have successfully tested a spare reaction wheel on Mars Odyssey in their effort to bring the spacecraft back into full operation.

After more than 11 years of non-operational storage, the spare reaction wheel passed preliminary tests on Wednesday, June 12, spinning at up to 5,000 rotations per minute forward and backward. Odyssey engineers plan to substitute it for a reaction wheel they have assessed as no longer reliable. That wheel stuck for a few minutes last week, causing Odyssey to put itself into safe mode on June 8, Universal Time (June 7, Pacific Time).


Mars Odyssey put itself into safe mode on Friday when it detected problems with one of the three reaction wheels used to orient the spacecraft.

Mars Odyssey put itself into safe mode on Friday when it detected problems with one of the three reaction wheels used to orient the spacecraft.

If this space probe goes down, it will make it more difficult to rely data back from Opportunity, now on the Martian surface, and Curiosity, due to land in two months.