Posts Tagged ‘planetary’

Another round of the enduring hexagon mystery.
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With its dazzling system of icy rings, Saturn has been a subject of fascination since ancient times, says

Even now the sixth planet from the sun holds many mysteries, partly because its distance away makes direct observation difficult and partly because this gas giant (which is multiple times the size of our planet) has a composition and atmosphere, mostly hydrogen and helium, so unlike that of Earth.

Learning more about it could yield some insights into the creation of the solar system itself.

One of Saturn’s mysteries involves the massive storm in the shape of a hexagon at its north pole.


Cyclones in Jupiter’s atmosphere [image credit: NASA]

At the south pole of Jupiter lurks a striking sight—even for a gas giant planet covered in colorful bands that sports a red spot larger than the Earth, says

Down near the south pole of the planet, mostly hidden from the prying eyes of humans, is a collection of swirling storms arranged in an unusually geometric pattern.

Since they were first spotted by NASA’s Juno space probe in 2019, the storms have presented something of a mystery to scientists.

The storms are analogous to hurricanes on Earth. However, on our planet, hurricanes do not gather themselves at the poles and twirl around each other in the shape of a pentagon or hexagon, as do Jupiter’s curious storms.


Credit: NASA [click on image to enlarge]

The effects of relative proximity between these large moons seem to have been underrated. Not forgetting that Jupiter does have a big effect on Io, the closest Galilean moon to it.
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Jupiter’s “ocean world” moons may have strong gravitational effects on each other, raising big tides in each others’ subsurface seas, a new study suggests [ reporting].

Surprisingly, these moon-moon tidal forces might generate more heat in the satellites’ oceans than the gravitational tugs of giant Jupiter, study team members found.

“That’s kind of interesting, because Jupiter is the biggest mass in that system, so its tidal forces are much bigger than one moon on another,” lead author Hamish Hay, who performed the work while at the University of Arizona’s Lunar and Planetary Laboratory, said in a statement.



The presence of sulphur in the atmosphere hinted at this.
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A new study identified 37 recently active volcanic structures on Venus, reports

The study provides some of the best evidence yet that Venus is still a geologically active planet.

A research paper on the work, which was conducted by researchers at the University of Maryland and the Institute of Geophysics at ETH Zurich, Switzerland, was published in the journal Nature Geoscience on July 20, 2020.

“This is the first time we are able to point to specific structures and say ‘Look, this is not an ancient volcano but one that is active today, dormant perhaps, but not dead,'” said Laurent Montési, a professor of geology at UMD and co-author of the research paper. “This study significantly changes the view of Venus from a mostly inactive planet to one whose interior is still churning and can feed many active volcanoes.”


Researchers now want to ‘understand both the processes that excite the waves and the processes that act to damp the waves.’
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A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound, says

A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawaii at Mānoa, shows that the Earth’s entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.

In the case of the atmosphere, the “music” comes not as a sound we could hear, but in the form of large-scale waves of atmospheric pressure spanning the globe and traveling around the equator, some moving east-to-west and others west-to-east.

Each of these waves is a resonant vibration of the global atmosphere, analogous to one of the resonant pitches of a bell.

The basic understanding of these atmospheric resonances began with seminal insights at the beginning of the 19th century by one of history’s greatest scientists, the French physicist and mathematician Pierre-Simon Laplace.

Research by physicists over the subsequent two centuries refined the theory and led to detailed predictions of the wave frequencies that should be present in the atmosphere. However, the actual detection of such waves in the real world has lagged behind the theory.

Now in a new study by Takatoshi Sakazaki, an assistant professor at the Kyoto University Graduate School of Science, and Kevin Hamilton, an Emeritus Professor in the Department of Atmospheric Sciences and the International Pacific Research Center at the University of Hawaii at Mānoa, the authors present a detailed analysis of observed atmospheric pressure over the globe every hour for 38 years.

The results clearly revealed the presence of dozens of the predicted wave modes.

Full article here.

This is easily shown from the 74 Jupiter-Saturn conjunctions in the period:
1 J-S = 19.865036 sidereal years = 19.865036*365.25636 days = 7255.8307
(7255.8307*74) / 365.259636 (anomalistic year) = 1469.99945 (1470)

So Earth reaches its perihelion with the Sun exactly 1470 times per 74 J-S.

Both numbers are even, so why is the Dansgaard-Oeschger event not at half the period?
The short answer is: Neptune.


It now seems all planetary bodies can have magnetospheres, whether or not they have a significant magnetic field. This would also help to explain why Venus, with hardly any ‘protective’ magnetic field, has a much thicker atmosphere than Earth. Wikipedia might need an update.
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Five years after NASA’s MAVEN spacecraft entered into orbit around Mars, data from the mission has led to the creation of a map of electric current systems in the Martian atmosphere, reports

“These currents play a fundamental role in the atmospheric loss that transformed Mars from a world that could have supported life into an inhospitable desert,” said experimental physicist Robin Ramstad of the University of Colorado, Boulder.

“We are now currently working on using the currents to determine the precise amount of energy that is drawn from the solar wind and powers atmospheric escape.” Ramstad is lead author of a paper on this research published May 25 in Nature Astronomy.


Credit: NASA

This BBC link includes a video which shows the weakening of the magnetic field over the last 400 years (under ‘Magnetic flip’ sub-heading).
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In an area stretching from Africa to South America, Earth’s magnetic field is gradually weakening, says

This strange behaviour has geophysicists puzzled and is causing technical disturbances in satellites orbiting Earth.

Scientists are using data from ESA’s Swarm constellation to improve our understanding of this area known as the ‘South Atlantic Anomaly.’


Saturn’s hexagon

The ever-mysterious hexagon goes under the microscope, or telescope at least.

A rich variety of meteorological phenomena takes place in the extensive hydrogen atmosphere of Saturn, a world about 10 times the size of the Earth.

They help us to better understand similar features in the Earth’s atmosphere, says

Among Saturn’s atmospheric phenomena is the well-known “hexagon,” an amazing wave structure that surrounds the planet’s polar region.


Image credit: NASA-ISS

Dust storms are common in the region, and sometimes bear resemblance to weather events on Mars, according to NASA.
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A surging dust storm and trailing dust cloud captured an astronaut’s attention as the International Space Station (ISS) was passing over South America, says NASA’s Earth Observatory.

Dust storms are common in Patagonia and familiar for people in Comodoro Rivadavia, a coastal city in southern Argentina.

The primary source of dust is Lago Colhué Huapí, a shallow lake adjacent to the much deeper Lago Musters.


Magnetic North on the move [credit: ESA]

They have a go at doing so, anyway. To make it more complicated, the South Magnetic Pole is also moving, but at a much lesser rate.

European scientists think they can now describe with confidence what’s driving the drift of the North Magnetic Pole, says BBC News.

It’s shifted in recent years away from Canada towards Siberia.

And this rapid movement has required more frequent updates to navigation systems, including those that operate the mapping functions in smartphones.

A team, led from Leeds University, says the behaviour is explained by the competition of two magnetic “blobs” on the edge of the Earth’s outer core.


Image credit:

We’re told: ‘They refer to what they’ve found as ANTS, for Active Nearside Tectonic System’, which is ‘a mysterious system of tectonic features (ridges and faults) on the lunar nearside, unrelated to both lava-filled basins and other young faults that crisscross the highlands.’ Tectonic activity on one side only sounds a bit unlikely somehow, but what about tidal disturbance from Earth? We know it works the other way round: the Moon causes tides on Earth. Of course the Moon is tidally locked to Earth, hence the term ‘nearside’.
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Researchers have discovered a system of ridges spread across the nearside of the Moon topped with freshly exposed boulders, reports

The ridges could be evidence of active lunar tectonic processes, the researchers say, possibly the echo of a long-ago impact that nearly tore the Moon apart.

“There’s this assumption that the Moon is long dead, but we keep finding that that’s not the case,” said Peter Schultz, a professor in Brown University’s Department of Earth, Environmental and Planetary Sciences and co-author of the research, which is published in the journal Geology.

“From this paper it appears that the Moon may still be creaking and cracking—potentially in the present day—and we can see the evidence on these ridges.”



Super-rotation of its thick atmosphere, that is. The researchers believe their findings could also be a model for tidally-locked exoplanets with atmospheres.

An international research team led by Takeshi Horinouchi of Hokkaido University has revealed that this ‘super-rotation’ is maintained near the equator by atmospheric tidal waves formed from solar heating on the planet’s dayside and cooling on its nightside.

Closer to the poles, however, atmospheric turbulence and other kinds of waves have a more pronounced effect. The study was published online in Science on April 23.

Venus rotates very slowly, taking 243 Earth days to rotate once around its axis. Despite this very slow rotation, Venus’ atmosphere rotates westward 60 times faster than its planetary rotation.

This super-rotation increases with altitude, taking only four Earth days to circulate around the entire planet towards the top of the cloud cover. The fast-moving atmosphere transports heat from the planet’s dayside to nightside, reducing the temperature differences between the two hemispheres.

“Since the super-rotation was discovered in the 1960s, however, the mechanism behind its forming and maintenance has been a long-standing mystery,” says Horinouchi.


The atmosphere of Venus has surprised and puzzled scientists before.

Philosopher Nicholas Rescher once wrote, “Scientific discoveries are often made not on the basis of some well-contrived plan of investigation, but through some stroke of sheer luck,” quotes

For a team of researchers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, that statement couldn’t be more true.

What started as a dry run to ensure instruments on NASA’s Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft worked properly later turned into a 10-year saga that resulted in a chance discovery unrelated to the mission’s target planet, Mercury. It’s about Venus and its atmosphere.

The team reports April 20 in Nature Astronomy that data fortuitously collected by MESSENGER reveals a sudden rise in nitrogen concentrations at about 30 miles above Venus’ surface, demonstrating the planet’s atmosphere isn’t uniformly mixed, as expected. That finding upends an understanding about Venus’ atmosphere that has prevailed for decades.


As the video reminds us: Earth’s atmosphere is mostly (78%) nitrogen. Plus about 21% oxygen at sea level, and a few minor trace gases – one or two of which some people like to fixate on.

Researchers have used a new geochemical tool to shed light on the origin of nitrogen and other volatile elements on Earth, which may also prove useful as a way to monitor the activity of volcanoes, says ScienceDaily.

Their findings were published April 16, 2020, in the journal Nature.

Nitrogen is the most abundant gas in the atmosphere, and is the primary component of the air we breathe. Nitrogen is also found in rocks, including those tucked deep within the planet’s interior.

Until now, it was difficult to distinguish between nitrogen sources coming from air and those coming from inside the Earth’s mantle when measuring gases from volcanoes.


Saturn’s aurora

The report says: ‘Density decreases with altitude, and the rate of decrease depends on temperature.’ Or is it the other way round, i.e. density influences temperature?

The upper layers in the atmospheres of gas giants—Saturn, Jupiter, Uranus and Neptune—are hot, just like Earth’s, says

But unlike Earth, the Sun is too far from these outer planets to account for the high temperatures. Their heat source has been one of the great mysteries of planetary science.

New analysis of data from NASA’s Cassini spacecraft finds a viable explanation for what’s keeping the upper layers of Saturn, and possibly the other gas giants, so hot: auroras at the planet’s north and south poles.


Greenland ice sheet (east coast) [image credit: Hannes Grobe @ Wikipedia]

Of course the other question about the start of an ice age still remains.

New University of Melbourne research has revealed that ice ages over the last million years ended when the tilt angle of the Earth’s axis was approaching higher values, reports

During these times, longer and stronger summers melted the large Northern Hemisphere ice sheets, propelling the Earth’s climate into a warm ‘interglacial’ state, like the one we’ve experienced over the last 11,000 years.

The study by Ph.D. candidate, Petra Bajo, and colleagues also showed that summer energy levels at the time these ‘ice-age terminations’ were triggered controlled how long it took for the ice sheets to collapse, with higher energy levels producing fast collapse.

Researchers are still trying to understand how often these periods happen and how soon we can expect another one.


Wikipedia says:

Dansgaard–Oeschger events (often abbreviated D–O events) are rapid climate fluctuations that occurred 25 times during the last glacial period. Some scientists say that the events occur quasi-periodically with a recurrence time being a multiple of 1,470 years, but this is debated. —

The 25 occurrences of 1470 years are represented in this synodic chart posted in the comments of our 2018 blog post:
Possible origin of Dansgaard-Oeschger abrupt climate events.

Re. the ‘debate’, let’s take a line from this paper:
On the 1470-year pacing of Dansgaard-Oeschger warm events
Michael Schulz
First published: 01 May 2002
Citations: 99
‘a fundamental pacing period of ~1470 years seems to control the timing of the onset of the Dansgaard-Oeschger events.’

Another study: Timing of abrupt climate change: A precise clock
Stefan Rahmstorf
First published: 21 May 2003

An analysis of the GISP2 ice core record from Greenland reveals that abrupt climate events appear to be paced by a 1,470-year cycle with a period that is probably stable to within a few percent; with 95% confidence the period is maintained to better than 12% over at least 23 cycles. This highly precise clock points to an origin outside the Earth system; oscillatory modes within the Earth system can be expected to be far more irregular in period.

[bold added]

However, researchers often admit defeat when looking for a viable mechanism to explain its regularity, or just say there isn’t one to date.

Kepler’s trigon – the orientation of consecutive Jupiter-Saturn synodic periods, showing the repeating triangular shape (trigon).

Returning to the synodics chart, a relevant number doesn’t appear in it. The Jupiter-Saturn conjunction of 19.865~ years is an important period in the solar system, and it returns to almost the same position after every three occurrences, as Johannes Kepler noted with his ‘trigon’, centuries ago.

We can work out the rate of movement per conjunction in degrees:
360 – ((360 / S) * J-S) = 117.147 degrees
(360 / 117.147) * J-S = 61.046482y (‘JS-360’)
[Data: ]

Then, from the chart:
1470*25 / ‘JS-360’ = 602.00029
Check: (602*360) / 117.147 = 1849.983 (1850 J-S, see chart)
Since ‘JS-360’ is almost exactly a whole number (602), the Jupiter-Saturn conjunction should be in its original position at the end of the 25 D-O cycles.

Adding 602 to the orbits of each planet = multiples of 25:
223(N) + 602 = 825 (25*33) = 1850-1025(S-N)
[33 = 74-41]
1248(S) + 602 = 1850 (25*74)
3098(J) + 602 = 3700 (25*74*2)

Another way to get multiples of 25:
Add 2 to each orbit number (see chart), and subtract 2 from 602.

More on the 602 number:
602 = 14*43
14*61.046482y = 854.651y
43 J-S = 854.197y
These two results are only about half a year apart, and we find:
43*43 = 1849 J-S
Add 1 = 1850 J-S completing the 25 D-O cycle.

43*61.046482y = 2625 years (2624.9987)
1470:2625 = 14:25 ratio
1470*25 = 2625*14 (hence 602 of ‘JS-360’ = 14*43)

Obliquity note:
28 D-O = 41160 years, a fair match to the expected 41 kyr period.
One paper refers to a fit between D-O and obliquity.
Others support the notion of a link — possibly a topic for another post.
(28*25*1470 = 1,029,000 years)

Example of a 1470 year period from Arnholm’s solar simulator — click on image to enlarge:

Showing Neptune, Jupiter, Saturn and Earth.
* * *
Another one — Jupiter, Neptune, Saturn

New laser technology delves into Earth’s history.
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Earth turned faster at the end of the time of the dinosaurs than it does today, reports, rotating 372 times a year compared to the current 365, according to a new study of fossil mollusk shells from the late Cretaceous.

This means a day lasted only 23 and a half hours, according to the new study in AGU’s journal Paleoceanography and Paleoclimatology.

The ancient mollusk, from an extinct and wildly diverse group known as rudist clams, grew fast, laying down daily growth rings. The new study used lasers to sample minute slices of shell and count the growth rings more accurately than human researchers with microscopes.


Mars from NASA’s Hubble Space Telescope

Tales of the unexpected on Mars: ‘Day-night fluctuations and things that pulse in the dark’, and other mysteries. What’s unique to Mars?

New data gleaned from the magnetic sensor aboard NASA’s InSight spacecraft is offering an unprecedented close-up of magnetic fields on Mars, says

“One of the big unknowns from previous satellite missions was what the magnetization looked like over small areas,” said lead author Catherine Johnson, a professor at the University of British Columbia and senior scientist at the Planetary Science Institute.

“By placing the first magnetic sensor at the surface, we have gained valuable new clues about the interior structure and upper atmosphere of Mars that will help us understand how it – and other planets like it – formed.”