science – Page 170 – Behind The Black

Jupiter’s endless interweaving storms

September 20, 2022 1:01 pm Robert Zimmerman

Cool image time! The photo to the right, rotated so that north is up and then reduced slightly to post here, was created by citizen scientist Thomas Thomopoulos from a raw photo taken by Juno during its 44th orbit of Jupiter.

To bring out the details Thomopoulos enhanced the colors, then enlarged the entire photo and cropped the area of interest.

Unfortunately, the Juno team that releases these photos does not provide information for easily establishing scale. In an email to me Thomopoulos noted that the largest circular storm in the northern half of the image is likely a vortex, which on Jupiter tend to range from 600 to 3,500 miles in diameter. He also noted that Juno was a little less than 27,000 miles away from Jupiter when this photo was snapped on August 17, 2022. Thus, I suspect this particular vortex sits on the larger end of that size range, which makes it a little less than half the size of the Earth.

As for the colors, as with many similar Juno images, the white clouds appear to almost always sit at the top of these storms and jets, almost like thunderheads.

Though the largest feature here is that large vortex to the north, most of the gigantic Jupiter storms visible seem instead to form as bands, the storms churning about madly as they are driven along the gas giant’s very fast ten hour rotation period.

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The strange scattered rocks of Gediz Vallis on Mars

September 20, 2022 10:28 am Robert Zimmerman

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Cool image time! The photo to the right, reduced to post here, was taken on August 20, 2022 by Curiosity’s high resolution camera. It shows some of the scattered and very delicate rocks that it is finding on the floor of Gediz Vallis, the valley the rover had been striving for since landing more than a decade ago and finally entered in mid-August.

Because of Mars weak gravity, about 39% of Earth’s, and very thin atmosphere, about 1% of Earth’s, it is possible for surface rocks to erode into such delicate shapes. The shapes appear to be further encouraged by the many layers that exist in Mars, with each layer having different characteristics. In the case of the hanging flakes to the right, these layers were more resistant to erosion and thus remains intact while material above and below was slowly blown away.

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Some scientists make educated guess as to the number of ants on Earth

September 20, 2022 9:38 am Robert Zimmerman

It’s time for junk science! By combing through thousands of research papers, a team of scientists have estimated the Earth’s population of ants numbers approximately 20 quadrillion.

So for the work, researchers combed through 12,000 reports from databases in many languages, including Bulgarian and Indonesian, finding 489 studies with rigorous enough methods of collecting and counting ants to be included. Most of the studies were not focused on ants per se but on larger questions of biodiversity and evolution and just happened to sample ants. The team was surprised to find how concentrated ants are in the tropics, being most plentiful there in savannas and moist forests.

This estimate is 2 to 20 times higher than previous guesses. It is also a somewhat pointless exercise, mostly because there is no way to check the number. It is simply an educated guess, from which little real knowledge can be gleaned.

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Webb instrument has technical issue partly preventing its use

September 20, 2022 9:31 am Robert Zimmerman

Because a an issue with the mid-infrared instrument (MIRI) on the James Webb Space Telescope, the telescope’s engineering team has paused use of that instrument while it reviews the situation.

On Aug. 24, a mechanism that supports one of these modes, known as medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation. This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode. Following preliminary health checks and investigations into the issue, an anomaly review board was convened Sept. 6 to assess the best path forward.

The Webb team has paused in scheduling observations using this particular observing mode while they continue to analyze its behavior and are currently developing strategies to resume MRS observations as soon as possible. The observatory is in good health, and MIRI’s other three observing modes – imaging, low-resolution spectroscopy, and coronagraphy – are operating normally and remain available for science observations.

I am quoting almost entirely NASA’s short announcement. The announcement is vague, confusing, and (quite typically) written to minimize the reality of the issue. I can’t figure out how MIRI’s other observing modes are available if they have paused use of a mechanism that allows them to choose modes.

Regardless, Webb is awful young to have this kind of problem.

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Interstellar clouds backlit by nearby massive star

September 19, 2022 1:27 pm Robert Zimmerman

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Cool image time! The photo to the right, cropped and reduce to post here, was taken by the Hubble Space Telescope of what astronomers believe is a newly formed massive star about 9,000 light years away that has periodically spewed out material during eruptions.

The scientists hope to use Hubble to determine the speed in which this material is flying away from the star by taking pictures at intervals and then measuring the amount of change from image to image. This data will also allow the scientists to better gauge the distance to this star, as well as its actual mass, information that will help them better understand what is happening.

I highlight this picture however simply because of its beauty. The interstellar clouds on the left are all apparently backlit by the brightest star on the right, and thus their shape is easy to perceive.

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InSight’s seismometer detects its first new impact on Mars

September 19, 2022 1:13 pm Robert Zimmerman

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Using data from InSight’s seismometer that suggested a new impact had occurred at a specific location on September 5, 2022 on Mars, scientists used the high resolution camera on Mars Reconnaissance Orbiter (MRO) to search and find that impact.

The photo to the right, reduced to post here, is that MRO photo.

The initial impact itself created a small marsquake that was detected by InSight’s seismometer. The instrument recorded seismological data that showed the moment the meteoroid entered Mars’ atmosphere, its explosion into pieces in the atmosphere, and finally, the impact that created a series of at least three craters in the surface.

MRO then flew over the approximate site where the impact was “felt” to look for darkened patches of ground using its Context Camera. After finding this location, HiRISE captured the scene in color. The ground is not actually blue; this enhanced-color image highlights certain hues in the scene to make details more visible to the human eye – in this case, dust and soil disturbed by the impact.

This was thus the first new Martian impact detected based on its actual occurrence, rather than simply finding a change between two photos taken at different times. The latter only tells you a time period when the impact occurred. InSight’s detection here marks the impact’s exact moment.

Nor is this the only such discovery. It appears that InSight detected at least two other impacts (here and here), that only subsequently were linked to MRO impacts. In those cases, the new impact had already been found by MRO, and only afterward were scientists able to identify its seismic vibration in InSight data, thus pinpointing the exact date it took place.

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Valeri Polykov, holder of the record’s longest stay in space, passes away

September 19, 2022 10:00 am Robert Zimmerman

Valeri Polykov

Russian astronaut Valeri Polykov, who holds the record for the longest spaceflight yet of any human in history, has passed away at the age of 80.

In 1994 and 1995 Polykov spent 437 days on Russia’s space station Mir, the equivalent of fourteen months and two weeks. His thoughts at launch, as he told me personally when I interviewed him while writing Leaving Earth, were not so confident:

“What if something goes wrong?” [he explained]. “I had sacrificed so much time. The government has spent so much, more than they can afford. And I’ve learned so much for them myself, for them.

“Better I die if something went wrong,” he thought. “Better if I had a gun to shoot myself.”

Nothing went wrong however. Polykov, a doctor, had pushed for this long mission to find out if it would be possible for a person to function after a year-plus of weightlessness upon arrival on Mars. Originally planned to last 18 months, circumstances eventually shortened it to 14 months-plus. When Polykov came home in March 1995, he managed to walk a few steps on his own, shortly after being removed from the capsule. To his mind, he had proved that a person could function on their own on Mars after such a long flight.

Others disagreed. As I wrote in Leaving Earth, though he was almost normal within a week of landing,

Polykov had come back to Earth very weak. For at least those first few hours, he needed help from those around him. Any spacefarer arriving on Mars after a year in space must be prepared to face that same challenge.

Regardless, Polykov, like Brian Binnie, was one of the early giants in space exploration. His contribution must not be forgotten.

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Webb takes its first infrared image of Mars

September 19, 2022 9:12 am Robert Zimmerman

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Astronomers have now released the the James Webb Space Telescope’s first infrared image of Mars, taken on September 5, 2022.

The image to the right, cropped and reduced to post here, shows some of the data obtained. Because Mars is so close, it is actually too bright for Webb’s instruments. To get any data, the exposures were very very short, and still the brightest areas — as indicated by large areas of yellow — are overexposed. The cause of the different brightness of Hellas Basin, however, is not simply because the basin — the deepest point on Mars — is cooler.

As light emitted by the planet passes through Mars’ atmosphere, some gets absorbed by carbon dioxide (CO2) molecules. The Hellas Basin – which is the largest well-preserved impact structure on Mars, spanning more than 1,200 miles (2,000 kilometers) – appears darker than the surroundings because of this effect. “This is actually not a thermal effect at Hellas,” explained the principal investigator, Geronimo Villanueva of NASA’s Goddard Space Flight Center, who designed these Webb observations. “The Hellas Basin is a lower altitude, and thus experiences higher air pressure. That higher pressure leads to a suppression of the thermal emission at this particular wavelength range [4.1-4.4 microns] due to an effect called pressure broadening. It will be very interesting to tease apart these competing effects in these data.”

The NASA press release says the scientists are preparing a paper analyzing the spectral data and what it revealed about “dust, icy clouds, what kind of rocks are on the planet’s surface, and the composition of the atmosphere,” I suspect however that Webb’s capabilities for studying Mars are much more limited than implied, and that it will over time take much fewer images of the red planet, compared to Hubble.

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Deep inside the youngest flood lava event on Mars

September 16, 2022 1:30 pm Robert Zimmerman

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Cool image time! Today we return to the Athabasca Valles flood lava event, believed to be the youngest major lava event on Mars that I highlighted in a cool image last week.

Then, I showed two meandering lava flows near the edge of this Great Britain-sized flood lava plain, produced 600 million years ago in only a matter of weeks. Today, we take a look deep within the lava plain. The photo to the right, rotated, cropped, and reduced to post here, was taken on May 6, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label “a lava-crater interaction.”

In plain English, we are looking at a crater that has been inundated by the flood lava, filling it.
» Read more

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Starlink being tested in Antarctica

September 16, 2022 9:33 am Robert Zimmerman

Capitalism in space: The National Science Foundation (NSF) has begun testing a single Starlink terminal at its McMurdo station in Antarctic, with the hope that the service can improve communications at the station significantly.

Everyone at the base shares a 17 Mbps link, according to the United States Antarctic Program, which severely limits what people can do. The station actually blocks people from using high-bandwidth apps like Netflix, cloud backups, and video calls, with the exception of once-weekly Skype or FaceTime sessions at a public kiosk or mission-critical communications.

The addition of Starlink probably doesn’t mean that McMurdo residents will be able to hold a Netflix movie night or anything — the terminals can handle around 50-200 Mbps, which still isn’t a ton to go around, even during the winter when far fewer people are at the base — but it could help make transferring important scientific data off of the icy continent easier.

According to SpaceX’s plans, this new service in Antarctica means that by year’s end Starlink will be available on all seven continents.

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New theory: Saturn’s rings came from a lost and destroyed moon

September 16, 2022 9:24 am Robert Zimmerman

The uncertainty of science: According to a new computer simulation, scientists have proposed that the reason Saturn’s rings are tilted 27 degrees is because they were created by the destruction of a moon 160 million years ago, an event that was also linked to the way the orbits of Saturn and Neptune interact, combined with the on-going slow evolutionary changes in Titan’s orbit around Saturn.

Wisdom and his colleagues believe Saturn acquired its tilt because of a peculiar synchronicity: the precession of Saturn’s spin axis—the way it wobbles like a top with a particular rhythm—is suspiciously in tune with a precession in Neptune’s orbit. If Saturn and Neptune were trapped in this resonance, Saturn’s tilt would be “kind of vulnerable to other forces that could cause it to change,” says Rola Dbouk, an MIT graduate student in planetary science. In 2020, Cassini scientists discovered what the study team thinks is that external stimulus: Titan, Saturn’s largest moon, is migrating away from Saturn by 11 centimeters a year. In a study published today in Science, Dbouk, Wisdom, and colleagues show how Titan’s migration, in combination with the Saturn-Neptune resonance, could have ratcheted up Saturn’s tilt over the course of 1 billion years.

The work also yielded a potential explanation for the origin of Saturn’s rings. Using Cassini’s measurements of Saturn’s gravitational fields to model the planet’s interior structure, the researchers refined calculations for the wobble of Saturn’s spin axis and found it is no longer in sync with Neptune. “Something kicked it out of the resonance,” Dbouk says. They first ruled out the possibility that chaotic changes in the orbits of some of the largest of Saturn’s dozens of moons could be responsible. But when they added another moon to the mix, things got interesting.

In simulations, the researchers included an object about the size of Iapetus, Saturn’s third largest moon, orbiting about 43 Saturn radii out—between the orbits of Titan and Iapetus. They found this moon could have provided the necessary nudge to the resonance if it were suddenly knocked from its orbit because of chaotic interactions with its neighbors about 160 million years ago.

To say that this theory is uncertain is no different that saying the sky is blue. It is so uncertain that it is difficult to take it seriously. It could be right, but as one scientist quoted at the article noted, there is no way to test it.

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