Tag: science

A dry lakebed on Mars?

12:37 pm

Evidence of a past lake in a crater on Mars
Click for original image.

Today’s cool image illustrates in some ways the uncertainty of science. The photo to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 1, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team intriguingly labeled it “Small Candidate Lake Deposit Downstream of Alluvial Fan.” I am not sure what they consider that lake deposit in the full image, so I have focused on the area of stucco-like ground, which resembles bedrock that has been corroded by some water process.

This area is just to the east of the central peaks of an unnamed 25-mile-wide crater in the southern cratered highlands. Many of the craters in this region are believed by scientists to have once harbored lakes formed by run-off from the glaciers that once existed on the craters’ inner rim. In this case it appears this stucco area is the head of an alluvial fan, coming down from the crater’s central peaks. You can see its beginning in this MRO high resolution image of the central peaks, taken in November 2016. As defined geologically,

An aluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation.

In this case the terrain is now arid, but shows evidence it once was icy wet.
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Curiosity’s drill fails for the fourth time to drill into the marker band layer on Mt Sharp

5:11 pm

The fourth attempt yesterday to use Curiosity’s drill to drill into the marker band layer on Mount Sharp once again was unable to drill down deep enough to obtain a sample.

Despite giving it the “old college try,” Curiosity’s attempt to drill into the Marker Band at the “Encanto” site did not reach sampling depth. Because other rocks around the rover look similar to “Encanto” and are likely also too hard to drill, the Science Team decided to convert the plan to a “Touch and Go.”

Although the Science Team is disappointed to leave this Marker Band location without a sample, Curiosity will use MAHLI, APXS, and ChemCam LIBS to analyze the chemistry and texture of the shallow “Encanto” drill hole and tailings, targeting the intriguing light-toned material exposed in the wall of the drill hole. We may see another location in the Marker Band worth sampling in the near future, but even if we don’t, there will certainly be many more exciting drilling opportunities to look forward to as Curiosity continues her climb up Mt. Sharp!

This drilling difficulty is not a surprise. The marker band is a very distinct flat layer that is seen at about the same elevation on all sides of Mount Sharp. It flatness suggests it is resistant to erosion, which also suggests its material will be hard. The inability of Curiosity’s drill to penetrate it only confirms this.

It also makes getting a drill sample to test even more intriguing. I suspect that the science team is going to try a few more times as it travels forward across the band, as indicated by the red dotted line in the panorama below.
Panorama as of January 17, 2023
Click for full image.

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Jupiter and two of its Moons, as seen by Cassini during 2018 fly-by

4:41 pm

Cool video time! Back in December 2000 the spacecraft Cassini made a fly-by of Jupiter on its way to Saturn, which it then orbited from 2004 to 2017. In 2018 JPL scientist Kevin Gil took the images from that flyby to create a short movie, first showing two of Jupiter’s moons, Io and Europa, as they drifted above the Great Red Spot.

Then, for the second half of the movie Gil used Cassini images taken when in orbit around Saturn to show the moon Titan moving across the rings of Saturn.

I have embedded this short video below. If I had posted this back in 2018, I don’t remember. No matter. It is amazing enough to watch again.

Hat tip BtB’s stringer Jay.
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New evidence suggests the Earth’s inner core no longer rotates faster than the planet’s outer layers

8:41 am

The uncertainty of science: The same scientists who in the late 1990s thought they had detected evidence that the Earth’s inner core rotates faster than the planet’s mantle now say that this faster rotation ceased sometime around 2009.

In 1996, Song and another researcher reported studying earthquakes that originated in the same region over three decades, and whose energy was detected by the same monitoring station thousands of kilometres away. Since the 1960s, the scientists said, the travel time of seismic waves emanating from those earthquakes had changed, indicating that the inner core rotates faster than the planet’s mantle, the layer just beyond the outer core.

…Now, Yang and Song say that the inner core has halted its spin relative to the mantle. They studied earthquakes mostly from between 1995 and 2021, and found that the inner core’s super-rotation had stopped around 2009. They observed the change at various points around the globe, which the researchers say confirms it is a true planet-wide phenomenon related to core rotation, and not just a local change on the inner core’s surface.

It is important to note that there has not been a consensus on this data, that some scientists even doubt the super-rotation ever existed. The data itself is sparse enough and includes enough gaps to allow for this disagreement, which also means this new conclusion is also uncertain.

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Communications issue shuts down one of Webb’s instruments

8:30 am

The near infrared instrument on the Webb Space Telescope, NIRISS, has been unavailable for science observations for more than a week due to a communications issue.

On Sunday, Jan. 15, the James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the instrument, causing its flight software to time out. The instrument is currently unavailable for science observations while NASA and the Canadian Space Agency (CSA) work together to determine and correct the root cause of the delay.

According to the update, the instrument’s hardware, as well as the rest of the telescope, has been unaffected and remains in good condition.

In November the telescope’s mid-infrared instrument MIRI experienced its own problems with one of its “grating wheels” that allows it to some spectroscopy. Since then the instrument has been in use, but it is unclear if the issue was resolved or observations have had to be adjusted to avoid the problem.

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Martian crater with mound of ice? mud? hardened sand?

12:17 pm

Crater with mound
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on October 31, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small 4,000-foot-wide crater that is practically filled with a smooth, almost perfectly spherical mound, with the rest of the crater interior filled with sand dunes and what appears to be glacial debris.

Is that mound also glacial debris, covered with a layer of dirt and dust to protect it? If so, one wonders how the ice ended up in this shape. There are other craters with similar mounds in this region, all suggesting glacial debris but with the same question. Craters with lots of near surface ice in this region more often have a squishy blobby look.

Is the mound instead possibly mud, expressing the existence of a mud/ice volcano? If so, it shows no central pit or caldera, which is typical of such things.

Is it hardened sand? Martian dust that gets blown into craters generally gets trapped there, building up over time. If so, however, why does it have a smooth almost perfectly rounded shape? The ripple sand dunes surrounding it are more like what you would expect.

The small craters on the mound also tell us that it is hardened and old, no matter what it is made of.
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Animation of Jupiter’s clouds

9:19 am

Cool video time! Using a photo taken by Juno during its 2018 fly-by of Jupiter, citizen scientist Thomas Thomopoulos has created a short animation showing the flow of Jupiter’s clouds. He also added some 3D relief by assigning elevation to the image’s greyscale, with lighter regions assigned higher altitudes.

I have embedded the animation below. Run it at the slowest speed for the best effect. It is quite spectacular, though it is also important to note that it is not reality. Thomopoulos is simply giving us a hint of the natural evolution of the cloud structures, both in elevation and in time.

You can see another equally impressive animation by Thomopoulos here of several of Jupiter’s polar storms, using AI technology to smooth out the loop.
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The youngest flood lava on Mars, flowing past a crater

2:07 pm

Crater with lava flow
Click for full image.

Cool image time! The photo to the right, rotated, cropped, reduced to post here, was taken on December 3, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The title given to this image by the MRO science team is “Upstream Edge of Crater in Athabasca Valles.” The crater itself is a pedestal crater, uplifted from the surrounding terrain because it was more resistant to erosion.

The material to the east of the crater’s rim definitely appears to have flow characteristics, but is it wet mud, glacial ice, or lava?

To figure this out we need as always some context. The latitude, 8 degrees north, immediately eliminates mud or glacial material. This location is in the dry equatorial regions of Mars, where no near surface ice has yet been found. Thus, the flow features are likely hardened lava.

What direction however was the flow? Was it flowing to the north, widening as it moved past the pedestal crater? Or was it to the south, narrowing as it pushed past that crater? To answer this question we need to widen our view.
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Ingenuity completes 40th flight

9:52 am

Overview map
Click for interactive map.

As predicted by the Ingenuity engineering team on January 17, 2023, the Mars helicopter yesterday completed its 40th flight, flying approximately 92 seconds and 584 feet to the northwest to place it at the head of the hollow that Perseverance will travel to climb up onto the delta that flowed into Jezero Crater sometime in the past.

The green dot on the overview map to the right shows the helicopter’s position, post flight. The blue dot shows Perseverance’s present position. The red dotted line indicates the rover’s future route.

At the moment, only eleven images have been returned from the flight, and these only show the first 20 seconds of flight. The flight however has been added to the helicopter’s flight log, which shows that Ingenuity actually flew about 23 feet farther and 7 seconds longer than expected. This extra distance was likely because the helicopter needed to find a good landing site, using its upgraded software that allows it to fly over rougher terrain.

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Lucy team suspends efforts to complete deployment of unlatched solar panel

8:25 pm

Lucy's planned route
Lucy’s planned route to explore the Trojan asteroids

The Lucy science team has decided to suspend its efforts to complete the deployment of the unlatched solar panel that failed to fully open shortly after launch, having determined that little can be accomplished while the spacecraft is so far from the Sun.

A series of activities in 2022 succeeded in further deploying the array, placing it into a tensioned, but unlatched, state. Using engineering models calibrated by spacecraft data, the team estimates that the solar array is over 98% deployed, and it is strong enough to withstand the stresses of Lucy’s 12-year mission. The team’s confidence in the stability of the solar array was affirmed by its behavior during the close flyby of the Earth on Oct. 16, 2022, when the spacecraft flew within 243 miles (392 km) of the Earth, through the Earth’s upper atmosphere. The solar array is producing the expected level of power at the present solar range and is expected to have enough capability to perform the baseline mission with margin.

The team elected to suspend deployment attempts after the attempt on Dec. 13, 2022, produced only small movement in the solar array. Ground-based testing indicated that the deployment attempts were most productive while the spacecraft was warmer, closer to the Sun. As the spacecraft is currently 123 million miles (197 million km) from the Sun (1.3 times farther from the Sun than the Earth) and moving away at 20,000 mph (35,000 km/hr), the team does not expect further deployment attempts to be beneficial under present conditions.

The spacecraft will do another Earth fly-by on December 12, 2024, which will send it to the Trojans on the left side of the map above. Before that Lucy will do a mid-course correction in February 2024, at which time the engineers will reassess whether to try again to latch the panel, when Lucy is closer to Earth and thus also closer to the Sun.

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Machete Mesa on Mars

12:41 pm

Machete Mesa on Mars
Click for full image.

Cool image time! The picture to the right, cropped to post here, was taken on November 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a variety of ridges in a region of Mars called Arabia Terra, which is also the largest transition zone between the Martian southern cratered highlands and the northern lowland plains.

While this picture illustrates some nice geological facts about Mars (see below), I post it simply because of the dramatic sharpness of the ridge on top of the mesa, which I guess is several hundred feet high, but only a few feet across, at most, at its peak. A hike along this ridgeline would be a truly thrilling experience, one that the future human settlers on Mars will almost certainly find irresistible. Put this location on your planned tourist maps of Mars. It will likely be an oft-visited site.
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Geotail mission finally ends after 30 years

9:18 am

Though initially planned as a four year mission, the Geotail probe — designed to study the Earth’s magnetosphere — finally failed on June 28, 2022 after 30 years of operation.

With an elongated orbit, Geotail sailed through the invisible boundaries of the magnetosphere, gathering data on the physical process at play there to help understand how the flow of energy and particles from the Sun reach Earth. Geotail made many scientific breakthroughs, including helping scientists understand how quickly material from the Sun passes into the magnetosphere, the physical processes at play at the magnetosphere’s boundary, and identifying oxygen, silicon, sodium, and aluminum in the lunar atmosphere.

The mission also helped identify the location of a process called magnetic reconnection, which is a major conveyor of material and energy from the Sun into the magnetosphere and one of the instigators of the aurora. This discovery laid the way for the Magnetospheric Multiscale mission, or MMS, which launched in 2015.

Though it failed in June, engineers worked until November attempting to recover the spacecraft. When those efforts failed, NASA officially ended the mission.

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