Tag: geology

Yutu-2 continues its travels on Moon’s far side

9:06 am

The square boulder being targeted by Yutu-2

An update on the Chinese lunar rover Yutu-2 has revealed that its science team has now decided to head towards a square boulder that the rover had recently spotted on the nearby horizon.

The photo from Yutu-2 to the right shows that boulder. The original update was at this Chinese-language website.

The boulder is presently about 260 feet away, which at pace Yutu-2 travels, about 100 feet per lunar day, will take about two to three lunar days to get there.

Yutu-2 has been traversing the floor of 115-mile-wide Von Kármán crater since January, 2019, a total of 36 lunar days, each about 14 Earth days long. The rover goes into hibernation during the lunar night, is then awakened each lunar morning to operate for about two-thirds of that lunar day, during which it travels about 100 feet, and is then returned to hibernation with the setting of the sun.

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Ingenuity’s images from 16th flight on November 21st

11:18 am

Ingenuity color image from 16th flight
Click for full image.

Cool image time! The photo to the right, reduced and enhanced to post here, was the first color image taken by Ingenuity during its 16th flight on Mars on November 21st. The picture was taken about fifteen seconds after take-off, and I think looks west toward the rim of Jezero Crater in the distance.

The flight itself was relatively short, essentially a quick hop about 380 feet to the north to land at the edge of the rough area dubbed Seitah. The team is going to slowly take the helicopter back to its initial landing field, Wright field, over several hops. This was the first.

If you want to peruse all 113 images from the flight, go here and set the sol range from 268 (November 20) to 274 (November 26). That will show all 113 images taken during the November 21st flight.

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Sculptured lava south of Olympus Mons?

10:51 am

Sculptured lava?
Click for full image.

Time for a cool image! The photo to the right, rotated, cropped, and reduced to post here, was taken on September 8, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a region of strangely sculptured terrain located several hundred miles south of Olympus Mons.

It appears the prevailing winds are to the west. The question is whether the wind is shaping a hard lava surface, over eons, or is shaping instead layers of dust or volcanic ash quickly and seasonally. At this location either is possible. In fact, we might even be seeing evidence of both at the same time.

The overview map below shows that the location is just outside the Medusae Fossae Formation, the largest volcanic ash deposit on Mars.
» Read more

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Volcanic vent on Mars

2:43 pm

Overview of Arsia Mons pits

To understand today’s cool image we really should start from a distance and zoom in. The overview map to the right focuses in on the two southernmost giant volcanoes in the string of three that sit to the east of Mars’ biggest volcano, Olympus Mons, and to the west of the planet’s biggest canyon, Valles Marineris.

The black dots mark the locations of the many high resolution photos taken by Mars Reconnaissance Orbiter that I have featured previously on Behind the Black. Many are isolated openings with no related geological features. Others appear to be skylights into a more extensive lava tube, hinted at by either a continuing surface depression or a series of similar skylights.

The white dot marks the location of today’s cool image, about 350 miles south of Arsia Mons’ caldera.
» Read more

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UAE Al-Amal Mars orbiter finds surprising variations in Mars atmosphere

10:32 am

Oxygen variations in Martian atmosphere
Click for full graphic.

The United Arab Emirates Al-Amal (“hope” in English) Mars orbiter has discovered unexpected variations of oxygen and carbon monoxide in the Martian atmosphere.

The EMM team had expected to observe a relatively uniform emission from oxygen at 130.4 nm across the planet and yet here we are, faced with unpredicted variations of 50% or more in the brightness.

The image to the right, cropped and reduced to post here, shows the variations in oxygen on Mars’s dayside. Though the map does not indicate the geography below, the concentration of oxygen in the northern latitudes appears to correspond to the planet’s northern lowland plains. In fact, the variations should not have been a surprise, since the surface of Mars has such a stark dichotomy between its northern and southern hemispheres.

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Craters in the soft Martian northern lowland plains

12:25 pm

Craters in the soft Martian northern lowland plains
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Cool image time! The photo to the right, cropped and reduced to post here, was a featured image today from the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The caption, written by Carol Weitz of the Planetary Science Institute in Arizona, focused on the wind patterns created within these craters.

These impact craters in the northern middle latitudes have interesting interiors: all of them have wind-blown (aeolian) ripples.

Outside of the craters and along the crater floors, the ripples are all oriented in the same direction. However, along the walls of some of the larger craters, the ripples are situated radially away from the center, indicating the winds moving inside the larger craters can be influenced by the topography of the crater wall.

Additionally, many of the larger craters have layered mesas along their floors that are likely sedimentary deposits laid down after the craters formed but prior to the development of the aeolian ripples.

I am further intrigued by the rimless nature of these craters, as well as the lack of significant rocky debris at their edges. They all look like the bolides that created them impacted into a relatively soft surface that, rather than break up into rocks and boulders, melted, flowed, and then quickly refroze into these depressions.

The location, as always, provides us a possible explanation.
» Read more

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Zhurong’s continuing travels on Mars

10:26 am

Zhurong overview map
Click for original map.

This past week the Chinese press released a new but limited update on the status of both its Mars orbiter Tianwen-1 and its Mars rover Zhurong.

The map to the right uses as its background a high resolution picture from Mars Reconnaissance Orbiter. I have superimposed Zhurong’s route in green. You can get an idea of how far the rover has traveled since resuming communications with Earth in late October by comparing this map with the one I posted then. After stopping at a small sand dune (the crescent-shaped white features), it curved around to head to the southeast towards a rough area and a trough that is thought to be filled with sediment.

Meanwhile, the orbiter has shifted its orbit, changing from one dedicated mainly as providing a communications relay between Zhurong and Earth to one that now allows it to begin a two-year photographic survey of Mars.

To supplement the resulting gaps in communications for Zhurong, China and the European Space Agency (ESA) have made their first test using ESA’s Mars Express satellite as a relay satellite. Both hope to know soon whether it worked.

In either case, Zhurong’s travels will likely be slowed somewhat due to the reduction in communications access.

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Snow on Martian dunes

12:58 pm

Snowy dunes near the Martian north pole
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Close-up of snowy dunes
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Cool image time! The first photo to the right, rotated, cropped, and reduced to post here, was taken on September 19, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what appears to be snow nestled in the hollows of many dunes.

The second photo, cropped to post here, shows in high resolution the area in the white box.

Is that snow water, or dry ice? The location is very far north, 76 degrees latitude, so it could be either. Since the photo was requested by Candice Hansen of the Planetary Science Institute in Arizona, I emailed her to ask. Her answer:

Early in the spring all the bright stuff is dry ice. As it gets later in the spring it is probably still mostly dry ice but with HiRISE images alone we cannot really distinguish the composition of the ice. In-between the dunes it is almost certainly bare ground late in the spring, but since the dunes are dark the surface just looks bright in contrast

This picture was taken in summer, which suggests the snow is probably water, not dry ice. Yet, all the snow is found in the north-facing hollows, places that will remain mostly in shadow at this high latitude, 76 degrees north. Thus, it is possible that the snow is the last remaining traces of the thin dry ice mantle that covers the Martian poles down to about 60 degrees latitude during the winter, and sublimates away in summer.

Hansen had requested a whole bunch of similar images of such snowy dunes. As she explained,
» Read more

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Scientists: Asteroid in an orbit entwined with the Earth might be Moon rock

11:45 am

Data obtained by scientists using ground-based telescopes now suggests that the small asteroid Kamo`oalewa, which has an orbit that makes it a quasi-Moon of the Earth, might have originally come from the Moon.

From their paper’s abstract:

We find that (469219) Kamoʻoalewa rotates with a period of 28.3 (+1.8/−1.3) minutes and displays a reddened reflectance spectrum from 0.4–2.2 microns. This spectrum is indicative of a silicate-based composition, but with reddening beyond what is typically seen amongst asteroids in the inner solar system. We compare the spectrum to those of several material analogs and conclude that the best match is with lunar-like silicates. This interpretation implies extensive space weathering and raises the prospect that Kamo’oalewa could comprise lunar material.

Kam’oalewa — which is only about 150 feet across — is one of five such quasi-Earth-moons. All orbit the Sun in orbits that are similar to the Earth’s and are such that the asteroids periodically loop around our planet each year.

This data will be useful to the Chinese, who are planning a mission to Kamo-oalewa in ’24 to grab samples.

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A volcanic extrusion on the floor of Valles Marineris?

2:52 pm

A volcanic extrusion on the floor of Valles Marineris?
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on August 31, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels a “possible contact between two units.”

I think that contact is the point where that eroded mountain touches the surrounding smooth canyon floor. The mountain itself looks to me to be a very eroded extrusion of lava that was placed there from below a very very long time ago, covered later by material, and now exposed for a long enough period that its surface appears to have been carved by wind and even possibly flowing water or ice.

Because it is lava it is more resistant to erosion, which is why it sits higher than the smooth terrain around it. Even though both experienced the same processes of wear over time, the mountain’s surface was only carved away partly, while the material that had been in the floor was washed away entirely.

This is all a guess. However, a look below at the overview map, showing this mountain’s location on Mars, as well as MRO’s wider view from its context camera, I think strengthens my hypothesis.
» Read more

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Frozen lake bed in the Martian high latitudes?

2:03 pm

Frozen lakebed in the Martian high latitudes?
Click for full image.

Today’s cool image comes from today’s Mars Reconnaissance Orbiter’s (MRO) high resolution picture of the day, rotated and cropped to post here. The original was taken back on March 28, 2017.

What formed those strange circular ridges and the many small cracks and hollows? The caption provided is somewhat vague and I think confusing:

This formation looks like a crater from a meteor impact rather than an ancient caldera of a volcano. Connected to the crater is a carved-out area that resembles a lake bed. At high resolution, we might be able to determine the likelihood of a water lake bed or lava bed. This observation will give insight into some of the interesting geology of this area.

The crater this caption is referring to is not visible in the image provided. It can be seen to the west of this location, in the MRO context camera picture below.
» Read more

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Curiosity: Approaching the saddle

9:21 am

The saddle ahead
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Cool image time! The photo to the right, reduced to post here, was taken on November 5, 2021 by Curiosity’s high resolution camera, and looks forward at its planned route up onto the saddle ahead, where the rover will turn right and climb up into Maria Gordon Notch. (See this October post for a map outlining the rover’s future travels.) I think that cliff face is between 40 to 60 feet high, though this is a very wild guess.

As noted by Abigail Fraeman of JPL on the Curiosity blog on November 3, 2021,

The terrain is beginning to steepen as Curiosity gets close to the end of this region, so even though we’re only a few drives away from our last drill site … we’ve already climbed 25 m higher!

The route ahead looks equally steep, though the ground actually appears less rough, with fewer large jagged boulders that Curiosity must avoid to protect its wheels.

It will likely be at least one to three weeks however before Curiosity gets to that saddle. The science team has begun a drilling campaign at the present location, and this will take time, depending on how many holes they decide to drill.

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