Tag: science

A gully in Mars’ glacier country

12:40 pm

Overview map

A gully in Mars' glacier country
Click for original image.

Cool image time! The picture to the right, cropped, reduced, sharpened, and brightened to post here, was taken on July 8, 2023 by the high resolution camera on Mars Reconnaisance Orbiter (MRO).

The white dot in the southwest corner of 146-mile-wide Lyot Crater on the overview map above marks the location, smack dab in the middle of the 2,000-mile-long northern mid-latitude strip I dub glacier country, since practically every high resolution picture shows some glacial features. This picture is no different. The material in the upper right of the picture appears to be ice that fills the crater and laps up against its interior slope. The gully appears to suggest a drainage down into that ice that partly covered it.

The elevation change from the high to low points is about 4,500 feet. What drained down this slope to carve this gully however remains an unsolved mystery, though most scientists presently favor some form of water or brine flow in the past and no longer active.

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The global wind patterns on Mars, determined by the orientation of dunes

10:54 am

Mars global wind patterns

Wind patterns at the Martina North Pole

Scientists have now roughly determined the global wind patterns on Mars, based on the orientation of one type of crescent-shaped dune called barchan dunes.

The global map above and the north pole map to the right come from figure 2 of the paper. The colored letters indicate the location of additional close-up images. On the polar map Olympia Undae is Mars’ largest dune field. From the abstract:

Crescent-shaped sand dunes are prevalent across the deserts of Mars. Here, we use the physical relationship between the shape of these dunes and the winds that form them to infer the directions of surface winds on Mars on a global scale. We find that dunes typically adhere to the global circulation patterns of Mars’ atmosphere, and that local topographic winds are mostly important in areas with high topographic roughness such as inside deep impact craters. Our global wind map can serve to calibrate numerical climate models, which in turn can help us learn about the recent and modern-day climate of Mars.

The arrows on both maps indicate the direction of the prevailing winds. This data will also help clarify the orientation of many surface features seen by Mars Reconnaissance Orbiter’s high resolution camera. This data also helps explain why the lander InSight never got a burst of wind to clear the dust from its solar panels, while the rovers Spirit and Opportunity did. The rovers were located in regions with clear prevailing winds. InSight was not.

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Webb takes an infared look at Saturn

10:36 am

Webb's five images of Saturn
Webb’s five images of Saturn. Click for original.

Using the Webb Space Telescope, scientists have obtained five infrared images of Saturn to get a more detailed look at the gas giant’s atmosphere and the molecules within it.

The image to the right is Figure 1 from the paper, showing the location of those five images on Saturn, placed over a much higher resolution Hubble Space Telescope optical image. The graph on the bottom shows the molecules revealed from spectroscopic data obtained by Webb’s infrared view. From the abstract:

We show evidence that a stratospheric circulation pattern detected by Cassini during northern winter has now fully reversed in northern summer, with the low-latitude stratosphere being cool and depleted in aerosols due to summertime upwelling. MIRI [Webb’s mid-infrared instrument] provides access to spectral regions that were not possible with the Cassini spacecraft, particularly in the 5–7 μm region where reflected sunlight and thermal emission blend together. Ammonia and phosphine are enriched at Saturn’s equator, suggesting strong mixing from the deeper troposphere. MIRI’s high sensitivity enables the first identification of previously unseen emission propane bands, along with the first measurements of the distribution of several gaseous species: tropospheric water, and stratospheric ethylene, benzene, methyl, and carbon dioxide.

The paper notes that this work still has uncertainty because when the infrared images were taken engineers were still working out the kinks for using Webb. Nonetheless, the results illustrate the large potential for future planetary discoveries from Webb.

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Another retraction looms of research claiming the discovery of superconductivity at room temperature

10:22 am

A March research paper that claimed the discovery of a compound that allowed superconductivity at room temperature is now facing retraction, making it the third superconductivity paper in which physicist Ranga Dias of University of Rochester was the lead author.

On 1 September, Nature attached an editor’s note to the March paper, warning readers that “the reliability of data presented in this manuscript is currently in question.” A week later, eight of the co-authors on the 11-person paper submitted a letter to Nature requesting the study be retracted, The Wall Street Journal first reported on Tuesday. Science has obtained the letter and additional documents, which raise concerns about the reliability of the data and Dias’s treatment of his co-authors. “We respectfully request and recommend that Nature issue a retraction,” conclude the signatories, who include five recent graduate students of Dias’s.

The article at the link is worth reading, as it details at length the bullying efforts of Dias to intimidate his co-authors by threatening legal action.

Before the co-authors sent their letter to Nature, Dias sent a cease-and-desist letter to six of them—five of his former graduate students and one U of R faculty member. He warned them about the “potential legal consequences of your actions and to consider the ethical implications of making baseless allegations against a colleague and fellow scientist.” Dias has previously sent cease-and-desist letters to other critics of his work.

This is not all. It appears that Dias used his position of authority to prevent an honest appraisal of his work, actions that are in utter violation of ethics and the scientific method.

While it is good that Dias’s chickens are now coming home to roost, his corrupt behavior is unfortunately too common now in the academic world, as indicated by the increase in retractions by 13,750% since 2000.

The good news however is that these retractions are helping to clean out that corruption. Though cleaning house will take time, it does appears to be happening. For example, according to the article, absolutely no students have enrolled in any of Dias’s classes at the University of Rochester.

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Anti-matter falls down, just like matter

9:31 am

The uncertainty of science: In a difficult particle physics experiment that carries large margins for error, scientists have determined that gravity appears to affect anti-matter the same as matter.

Quantitatively, the experiment indicates that antimatter experiences a pull from gravity that’s 75% as strong as that on ordinary matter, give or take 20%—a statistical agreement between the two. Hangst says 99.9% of physicists would have predicted the result. Still, he notes, “You have to do the experiment with an open mind.”

One must understand that, at atomic levels, the influence of gravity is practically nil. Extracting a measurment of its influence outside the other more powerful forces that dominate atomic particles, magnetism, the weak force, and the strong force, is difficult, to put it mildly.

The key is that the experiment result showed some influence of gravity, in the expected direction.

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The base of the long and deep south rim of Valles Marineris

1:14 pm

Overview map

The base of southern slope of Valles Marineris
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), showing the very bottom section of the long and endlessly deep south slopes of Valles Marineris, the largest known canyon in the solar system.

The many layers here are likely evidence of repeated volcanic flood lava events, over several billion years, after which the canyon formed.

On the overview map above the black dot in the southeast section of the area of the canyon dubbed Melas marks this location. The picture’s northeast corner is essentially the floor of Valles Marineris. From this point the elevation gain to the southwest corner of the picture 3.5 miles away is about 3,300 feet.

The rim itself however is far far higher, about fifty miles farther to the southwest and climbing about 22,000 feet more. Along those fifty miles you’d have to also climb over two intervening mountain ranges, one about 4,000 feet high and the second about 6,000 feet high.

Valles Marineris is big, so big it is hard to imagine a canyon this size. It makes many moutain ranges on Earth seem small.

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Nearest supernova in a decade confirms such stars lose mass prior to exploding

10:03 am

Gemini North image of supernova in Pinwheel Galaxy
Arrow points to supernova. Click for original image,
taken by the Gemini North telescope in Hawaii.

Astronomers making a detailed analysis of the data from the nearest supernova in a decade, SN 2023ixf and located in the Pinwheel Galaxy only 20 million light years away, has confirmed what other research had suggested, that such stars lose significant mass prior to exploding.

Within hours of going supernova, core-collapse supernovae produce a flash of light that occurs when the shock wave from the explosion reaches the outer edge of the star. SN 2023ixf, however, produced a light curve that didn’t seem to fit this expected behavior. To better understand SN 2023ixf’s shock breakout, a team of scientists led by CfA postdoctoral fellow Daichi Hiramatsu analyzed data from the 1.5m Tillinghast Telescope, 1.2m telescope, and MMT at the Fred Lawrence Whipple Observatory, a CfA facility located in Arizona, as well as data from the Global Supernova Project— a key project of the Las Cumbres Observatory, NASA’s Neil Gehrels Swift Observatory, and many others. This multi-wavelength study, which was published this week in The Astrophysical Journal Letters, revealed that, in sharp contradiction to expectations and stellar evolution theory, SN 2023ixf’s shock breakout was delayed by several days.

“The delayed shock breakout is direct evidence for the presence of dense material from recent mass loss,” said Hiramatsu, adding that such extreme mass loss is atypical of Type II supernovae. “Our new observations revealed a significant and unexpected amount of mass loss— close to the mass of the Sun— in the final year prior to explosion.”

The press release overstates the surprise of this discovery. Research in the last two decades of massive stars that are thought to be the progenitors of supernovae has shown that they lose mass in great amounts during eruptions. It was therefore not that surprising that this star experienced its own eruption prior to going supernova.

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Giant Magellan Telescope begins fabricating its seventh mirror

9:23 am

The fabrication of the seventh and last mirror for the Giant Magellan Telescope (GMT) has begun, with its completion and installation expected before the end of the decade.

In the project’s latest development, the Richard F. Caris Mirror Lab at another founding project partner, the University of Arizona, closed the lid on nearly 20 tons of the purest optical glass inside a one-of-a-kind oven housed beneath the stands of the university’s football stadium. The spinning oven will heat the glass to 1,165 degrees Celsius, so that as it melts, it is forced outward to form the mirror’s curved paraboloid surface. Measuring 8.4-meters in diameter—about two stories tall when standing on edge—the mirror will cool over the next three months before moving into the polishing stage.

Once assembled, all seven mirrors will work in concert as one monolithic 25.4-meter mirror—a diameter equal to the length of a full-grown blue whale—resulting in up to 200 times the sensitivity and four times the image resolution of today’s most advanced space telescopes.

A decade ago it was expected that this telescope in Chile would follow the Thirty Meter Telescope (TMT), while also working in parallel with it, with TMT covering the northern hemisphere and GMT covering the southern hemisphere. Now GMT is likely to forever work alone, as TMT remains blocked in Hawaii by the government and anti-western, anti-white protesters, and will likely never be built.

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Lacking funds to build its spacecraft, the VERITAS project team goes to Iceland

12:29 pm

Because NASA has cut almost all funding for the VERITAS mission to Venus in order to fund its overbudget, badly managed, and behind schedule Mars Sample Return mission, the VERITAS science team, held over with only a tiny holding budget for the next seven years, has taken a geology trip to Iceland to study the volcanoes there.

Early last month, one such field campaign took the mission’s science team to a barren and rocky region in Iceland. There, they studied rocks and surfaces near an active volcano named Askja. Such volcanic areas are being used as analogs of Venus to understand the different types of eruptions that may occur on its surface, and to test out various technologies and techniques to prepare for the VERITAS (or Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy) mission, which is not expected to launch sooner than 2031.

The article at the link focuses on this research, but the real story is this quote:

The VERITAS science team — which is being supported by a shoestring budget of $1.5 million until 2028, after NASA pulled the mission’s funding earlier this year and disbanded its entire engineering wing — collected samples of young rocks and recent lava flows near the Askja volcano that will be analyzed in a lab, according to a NASA statement.

The reason the budget was pulled was to scrap together any funds available from within NASA’s planetary program for that Mars Sample Return Mission, which is doing to the planetary program what the Webb Space Telescope did to NASA’s astronomy program: killing it. As long as NASA and Congress remain committed to that sample return mission, do not expect many new planetary missions to other planets to fly. Its budget has already quadrupled, and its launch is already expected to be delayed. Worse, the mission’s basic design remains tentative, with many major components nothing more than cool graphics on powerpoint presentations, despite having spent gigantic amounts already.

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A mountain buried by lava on Mars

10:53 am

A mountain buried by lava on Mars
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 6, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

This 500-to-600-foot-high hill represents what is likely the top of a much larger mountain, now buried by the flood lava that surrounds it. The edge of that flood lava can be seen best along the base of the hill’s northern slope, where this now hardened lava had washed up against that slope.

That this Martian mountain is very old can be discerned from two features. One, it had to have been there when the lava flowed, and scientists estimate these lava flows are at least one billion years old. Second, peak’s rounded shape and eroded edges (showing terraced layers) suggest it has been here for far longer, allowing Mars’ thin atmosphere and climate to weather it down.
» Read more

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Almost all of Mars’ geological mysteries in one spot

11:26 am

Almost all of Mars' geological history in one spot

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on June 30, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The scientists label it “Mesas in shallow trough,” but that is only describes a small part of what can be seen here, as I interpret it.

The picture itself shows a small portion of the floor of an unnamed 32-mile-wide crater, with the crater’s southeast interior rim beginning its rise in the lower right. First, note the meandering hollow in the upper left, suggesting some past flow. Second, note the pattern of small ridges on the flat crater floor, suggesting some past drying process that left cracks that later filled with material that formed the ridges at a later time. Third, the mesas themselves suggest chaos terrain, often formed on Mars in connection with glacial flows. Fourth, note that the trough which holds the mesas is on the edge of the crater floor, suggesting the trough and mesas mark the erosion that once occurred at the edge of some material, possibly ice, that once filled that floor.

The trough and small meander also signify something far larger that can only be seen when we zoom out.
» Read more

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OSIRIS-REx Sample from Bennu successfully recovered

10:18 am

Engineers today successfully recovered the asteroid sample capsule from the probe OSIRIS-REx, carrying several grams of material from the potentially dangerous asteroid Bennu.

The samples will be shipped to special facilities to protect the material from being exposed to Earth’s environment when the capsule is opened. It will take several months at least before the first research results are announced.

OSIRIS-REx, now renamed OSIRIS-APEX, now heads for the potentially dangeous asteroid Apophis, where it will orbit that asteroid beginning in 2029, shortly after Apophis makes its next close fly-by of Earth.

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