Tag: science

Researchers identify the oldest cheese so far found, from 3,600 years ago

10:01 am

One of the ancient cheese samples
Click for full image, figure 1 from the paper.

Researchers have confirmed that three clumps of organic matter taken from a gravesite in northwestern China are the oldest samples of cheese yet identified — more than 3,600 years old — and are in fact a specific kind of cheese, called kefir cheese.

And it’s not just any cheese: Cow and goat DNA, as well as the bacterium Lactobacillus kefiranofaciens, has indicated that these clumps were in fact kefir cheese, providing insight into the history and evolution of probiotics and human health. L. kefiranofaciens is still a key microorganism in kefir soft cheeses. The researchers also identified the microscopic fungal species Pichia kudriavzevii, which is a type of yeast found in kefir grains today.

These kefir grains contain a host of probiotic bacteria and yeast, which is key in fermenting milk to produce kefir products that have been studied for their health impacts, particularly in the areas of the immune and gastrointestinal systems, as well as metabolic regulation.

“Our observation suggests kefir culture has been maintained in Northwestern China’s Xinjiang region since the Bronze Age,” Fu said.

You can read the published paper here. The researchers suggest the cheese indicates not only the evolutionary history by which humans began creating such diary products, it also suggests the historical routes this process followed across the European and Asian continents.

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A puzzling striped rock on Mars

9:32 am

A striped rock on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on September 13, 2024 by one of the high resolution cameras on the Mars rover Perseverance. The rock’s striped nature makes it unique, unlike any feature spotted by any rover previously. From an update today:

The science team thinks that this rock has a texture unlike any seen in Jezero Crater before, and perhaps all of Mars. Our knowledge of its chemical composition is limited, but early interpretations are that igneous and/or metamorphic processes could have created its stripes. Since Freya Castle [the name the science team gave the rock] is a loose stone that is clearly different from the underlying bedrock, it has likely arrived here from someplace else, perhaps having rolled downhill from a source higher up. This possibility has us excited, and we hope that as we continue to drive uphill, Perseverance will encounter an outcrop of this new rock type so that more detailed measurements can be acquired.

Without doubt the rock’s rounded surface suggests it was ground smooth by either water or ice. That surface certainly resembles glacial cobble seen across the northeast of the U.S. where ice glaciers once covered the entire landscape. The rock also resembles river cobble, smoothed by flowing water.

The stripes however suggest that prior to its being smoothed, this rock underwent a much more complex geological process, whereby two different materials were intermixed and squeezed together.

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Layered mesas in Martian chaos

12:27 pm

Layered mesas in Martian chaos
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 19, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a 2,500 to 3,000-foot-high mesa with what the scientists call “bedrock layers”, most obvious as the lower terraces on the mesa’s western slopes.

What makes this mesa especially interesting is its overall shape. It appears as if something has taken a bite out of it, resulting in that bowl-like hollow on the mesa’s southern half.

Was this caused by an impact? Or has some other long term Martian processes caused it?

This mesa is just one of many mesas in a region of chaos terrain dubbed Hydraotes Chaos. Such chaos terrain is thought to form when erosion processes, possibly glacial in nature, that carve out canyons along faultlines, leaving behind mesas with randomly oriented canyons cutting in many directions.
» Read more

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Observations of solar flares do not match the standard model used to explain their origin

9:47 am

The uncertainty of science: When scientists carefully compared new and much more precise observations of the Sun’s solar flares with the standard model they have used for decades to explain their origin, they found unexpected differences, suggesting the model is wrong or imcomplete.

In sum, none of the processes simulated in accordance with the model proved capable of explaining the observational data. The conclusion drawn by the researchers was obvious to some extent: the standard model of solar flares needs to be reformulated, as required by the scientific method.

The scientists found that the two sources of each flare brightened at slightly different times. The model said these sources should brighten almost simulatanously, and no version of the model could explain the contradiction.

All this means is that the researchers simply don’t have enough data or understanding of the Sun to formulate a model that can fully explain the process. This study simply demonstrates this, but also provides a guide for soliving the problem.

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Bioengineered heart samples on ISS confirm that weightlessness weakens and ages the heart

9:33 am

Using 48 bioengineered heart samples that spent 30 days on ISS in 2020, scientists have confirmed other research that showed weightlessness not only weakens the heart, it ages it as well.

In addition to losing strength, the heart muscle tissues in space developed irregular beating (arrhythmias)—disruptions that can cause a human heart to fail. Normally, the time between one beat of cardiac tissue and the next is about a second. This measure, in the tissues aboard the space station, grew to be nearly five times longer than those on Earth, although the time between beats returned nearly to normal when the tissues returned to Earth.

The scientists also found, in the tissues that went to space, that sarcomeres—the protein bundles in muscle cells that help them contract—became shorter and more disordered, a hallmark of human heart disease. In addition, energy-producing mitochondria in the space-bound cells grew larger, rounder and lost the characteristic folds that help the cells use and produce energy.

Finally …[t]he tissues at the space station showed increased gene production involved in inflammation and oxidative damage, also hallmarks of heart disease.

None of this is ground-breaking, as it confirms numerous other past studies. What it does do however is confirm that long-term weightlessness is not good for a person’s heart. Many studies have shown that these issues mostly go away once astronauts return to Earth, but for any journey to Mars, involving two years in weightlessness, this data suggests the health risks will be far higher.

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More deterioration to Curiosity’s worst wheel

12:13 pm

Comparison of changing damage from Feb to Sept 2024
For original images go here, here, and here.

The science team for the Curiosity Mars rover on September 22, 2024 did another survey of its damaged wheels using the close-up camera on the end of the rover’s arm, and though most of the pictures appear to show the situation remains stable, the one wheel that has consistently shown the worst damage now shows some additional deterioration since February 2024.

To the right are comparison pictures, with the February 2024 picture on top and two new September 22, 2024 images showing the same damaged area, though from a different angle, on the bottom. (The technical captions for the bottom images can be found here and here.) I have labeled the treads, dubbed growsers, to make it easier to understand how the pictures all line up.

Previous images have looked down at the large damaged area from growsers 1 to 4, and since it was first spotted in 2022 showed it to be growing, but very slowly. The new pictures show that same damaged area from the side, which reveals that the zig-zag divider between growser #3 and growser #4 has now collapsed, so that this whole damaged area is now a major depression, as indicated by the two arrows.

Overall, the rover’s wheels appear to surviving the rough terrain of the foothills of Mount Sharp, though it is clear that care must continue to be taken to extend their life for as long as possible. That the rover has six wheels gives it a lot of redundancy, so that even if this one wheel eventually fails the rover will likely be able to continue to rove, but with some limitations. This wheel is the left middle wheel, which is helpful, as it is less necessary than the four corner wheels. [Update: According to a rover update today, this wheel is the right middle wheel, which contradicts an earlier report which described this as the left middle wheel. I note this contradiction for accuracy.]

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Land of cracks

1:26 pm

Land of cracks

Cool image time! The picture to the right, cropped to post here, was taken on June 28, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled a “terrain sample,” it was likely taken not as part of any specific research project but to fill a gap in the camera’s schedule in order to maintain its proper temperature. When the camera team needs to do this, they try to pick something interesting, but don’t always have that option.

In this case, the landscape available included the channel shown to the right. About a half mile wide and only about fifty feet deep, the floor of this canyon appears to have a lot of trapped dust, forming ripple dunes, along with a lot of knobby protrusions, likely small mesas. The canyon walls appear layered, with the erosion processes producing different features on opposite sides. On the southeast the layers appear to produce distinct terraces, while on the northwest the cliff is very steep at the top and then forms a long gently descending slope that appears formed of alluvial fill (from that cliff) and formed from erosion and landslides.
» Read more

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SpaceX finds a way to extend the launch window for Europa Clipper

10:03 am

The launch window for SpaceX’s launch of NASA’s Europa Clipper to Jupiter has now been extended a full week because the company has revised the launch process and made hardware changes.

The new launch window runs from October 10th to November 6th.

Usually the two side boosters come back to land at Cape Canaveral Space Force Station so they can be reused and sometimes the core booster is recovered at sea, but not this time. All their fuel will be used to get Europa Clipper on its way to Jupiter. Piloto said SpaceX “made some hardware modifications that enable the launch vehicle to utilize all the fuel in the boosters,” but couldn’t go into detail about what they are because the information is proprietary.

[The NASA official] added that SpaceX has gained experience in flying this configuration — it’s the 11th Falcon Heavy launch — and the company has “come up with a strategy to optimize throttling of the launch vehicle to get more performance out of it.”

NASA and SpaceX have also decided to use NASA’s orbiting communications constellation during the launch instead of ground stations, which increases their flexibility and margins.

I wonder if the FAA has approved these changes. Or even if anyone there even understands them.

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Webb takes an infrared look at a galaxy looked at by Hubble

12:21 pm

Comparing Hubble with Webb
For original images go here and here.

Cool image time! The bottom picture on the right, cropped to post here, is a just released false color infrared image of the galaxy Arp 107, taken by the Webb Space Telescope. The picture at the top is a previously released optical image taken by the Hubble Space Telescope and featured as a cool image back in September 2023. The Hubble image was taken as part of a survey project to photograph the entire Arp catalog of 338 “peculiar galaxies,” put together by astronomer Halton Arp in 1966. In this case Arp 107 is peculiar because it is actually two galaxies in the process of merging. It is also peculiar because the galaxy on the left has an active galactic nuclei (AGN), where a supermassive black hole is sucking up material and thus emitting a lot of energy.

The Webb infrared image was taken to supplement that optical image. The blue spiral arms indicate dust and star-forming regions. The bright orange object in the center of the galaxy is that AGN, clearly defined by Webb’s infrared camera.

When I posted the Hubble image in 2023, I noted that “if you ignore the blue whorls of the left galaxy, the two bright cores of these merging galaxies are about the same size.” In the Webb image the two cores still appear about the same size, but in the infrared they produce emissions in decidedly different wavelengths, as shown by the different false colors of orange and blue. The core of the galaxy on the right is dust filled and forming stars, while the core of the left galaxy appears to have less dust with all of its emissions resulting from the energy produced by the material being pulled into the supermassive black hole.

The universe is very active and changing, but to understand that process we humans have to look at everything across the entire electromagnetic spectrum, not just in the optical wavelengths our eyes see.

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Newly discovered potentially dangerous asteroid found to be a contact binary

11:38 am

Radar images of asteroid 2024ON
Click for original image.

Radar images taken during the close fly of a newly discovered potentially dangerous asteroid has revealed that it is a contact binary, formed by two objects stuck together to produce a single asteroid with a peanutlike shape.

Discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa in Hawaii on July 27, the near-Earth asteroid’s shape resembles that of a peanut. Like the asteroid 2024 JV33 that made close approach with Earth a month earlier, 2024 ON is likely a contact binary, with two rounded lobes separated by a pronounced neck, one lobe about 50% larger than the other. The radar images determined that it is about 755 feet (350 meters) long. Features larger than 12.3 feet (3.75 meters) across can be seen on the surface. Bright radar spots on the asteroid’s surface likely indicate large boulders. The images show about 90% of one rotation over the course of about six hours.

The radar images were taken one day before that close approach of 620,000 miles on September 17, 2024, and once again show that a large number of near-Earth asteroids, as much as 14%, are contact binaries. The data also helped better refine 2024ON’s orbit around the Sun, which show that though the asteroid has the potential to hit the Earth, its path will not do so for the foreseeable future.

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Phobos rising and Earth setting as captured together by Curiosity

10:56 am

Phobos and Earth in the Martian sky
Click for original image.

Cool image time! The picture to the right, enhanced and reduced to post here, was taken by the high resolution camera on the Mars rover Curiosity on September 5, 2024.

What makes this picture unique are the two tiny spots near the upper right. For the first time, Curiosity’s camera was able to capture both the Earth and the Martian moon Phobos in the same picture, when they were also very close to each other in the sky. From the caption:

NASA’s Curiosity Mars rover used its Mast Camera, or Mastcam, to capture this view of Earth setting while Phobos, one of Mars’ two moons, is rising. It’s the first time an image of the two celestial bodies have been captured together from the surface of Mars.

The image is a composite of five short exposures and 12 long exposures all taken on Sept. 5, 2024, the 4,295th Martian day, or sol, of Curiosity’s mission. An inset in the image [found here] shows Phobos on the left and Earth on the right. From the rover’s perspective, the inset area would be about half the width of a thumb held at arm’s length.

The dark shape in the lower left is one of the buttes that surround Curiosity as it has been climbing up Mount Sharp and traversing inside the Gediz Vallis slot canyon.

The inset provides a close-up of the two objects, but the resolution is poor. To me, it is much more interesting to look at the picture to the right, that shows what these two objects actually looked like in the sky of Mars.

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Some new “What the heck?” geology on Mars

1:12 pm

What the heck is going on here?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on April 21, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

My first reaction on seeing this picture was to scratch my head? What am I looking at? Are those fluted dark features going downhill to the south, or uphill to the north? What are they? Are they slope streaks? Avalanches? How do they relate to the flat-topped ground in the middle of the picture?

I have made it easier for my readers to interpret the picture by adding the “low” and “high” markers. We are looking at two parallel thin mesas about 1,400 feet high, with the saddle between them only dropping about 350 feet.

But what about the dark fluted features? To understand what these are requires more information.
» Read more

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