Archive for the ‘Celestial Mechanics’ Category

The Canterbury Swarm and the Taurids

Posted: December 10, 2020 by tallbloke in Astrophysics, Celestial Mechanics, moon

John Michael Godier: An exploration of the concept of the Canterbury meteor swarm and its links to the annual Taurid meteor shower and how these sometimes produce very large impacts on the moon and earth.


Nabta Playa

An inventory of Egyptian archaeo-astronomical sites for the UNESCO World Heritage Convention evaluated Nabta Playa as having “hypothetical solar and stellar alignments.” – Wikipedia.
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This 7,000-year-old stone circle tracked the summer solstice and the arrival of the annual monsoon season. It’s the oldest known astronomical site on Earth, says Discover magazine.

For thousands of years, ancient societies all around the world erected massive stone circles, aligning them with the sun and stars to mark the seasons.

These early calendars foretold the coming of spring, summer, fall and winter, helping civilizations track when to plant and harvest crops.

They also served as ceremonial sites, both for celebration and sacrifice.

These megaliths — large, prehistoric monuments made of stone — may seem mysterious in our modern era, when many people lack a connection with, or even view of, the stars.


From looking at the 30 day Wolf number and NOAA sunspot number it looks like Solar Minimum could have been in December, 2019 but possibly as late as mid-March this year. 

 Coincidentally, there are peaks in barycentric solar torque (dL/dt, where L denotes the Sun’s angular momentum, ref on March 19 and April 24, 2020: 


Browsing twitter recently I ran across this short video of a solar flare shot a few days ago.

After asking for some clarification on frame rate I was really intrigued.


ISSN 1063-7737, Astronomy Letters, 2019, Vol. 45, No. 11, pp. 778–790.c Pleiades Publishing, Inc., 2019. Nicola Scafetta1*,FrancoMilani2, and Antonio Bianchini3, 41Department of Earth Sciences, Environment and Georesources, University of Naples Federico II,Complesso Universitario di Monte S. Angelo, via Cinthia, 21, 80126 Naples, Italy 2 Astronomical Association Euganea, via N. Tommaseo, 70, 35137 Padova, Italy3INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy 4 Department of Physics and Astronomy, Universit `a degli Studi di Padova, via Marzolo 8, 35131 Padova, Italy Received May 18, 2019; revised October 2, 2019; accepted October 23, 2019


Visualization of the Radcliffe Wave. The wave is marked by red dots. The Sun is represented by a yellow dot to show our proximity to this huge structure. Courtesy of Alyssa Goodman/Harvard University

Scientists have previously reported evidence for a 26-million-year cycle of extinction on Earth, but the idea has remained controversial and unexplained. Now the discovery of the Radcliffe Wave may offer an explanation, but has anyone so far said so?

The team also found the wave interacts with the Sun. It crossed our path about 13 million years ago and will again in another 13 million years. What happened during this encounter is also unknown.

“There was no obvious mass extinction event 13 million years ago, so although we were crossing a sort of minefield back then, it did not leave an obvious mark,” Alves said. “Still, with the advent of more sensitive mass spectrometers, it is likely we will find some sort of mark left on the planet.”

13+13 = 26 (million). Can such a mark be found?
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From the article, ‘Something Appears to Have Collided with the Milky Way and Created a Huge Wave in the Galactic Plane’:


Solar system planets [image credit: BBC]

Well this looks interesting. Jean paul Zoghbi has discovered half integer relationships between star rotation rates and their planetary system’s angular momenta. The paper is here

Abstract With the discovery of now more than 500 exoplanets, we present a statistical analysis of the planetary orbital periods and their relationship to the rotation periods of their parent stars. We test whether the structural variables of planetary orbits, i.e. planetary angular momentum and orbital period, are `quantized’ in integer or half-integer multiples of the parent star’s rotation period. The Solar System is first shown to exhibit quantized planetary orbits that correlate with the Sun’s rotation period.

Variation in solar activity during a recent sunspot cycle [credit: Wikipedia]

A new study has found winters in northern China have been warming since 4,000BC – regardless of human activity – but the mainland scientists behind the research warn there is no room for complacency or inaction on climate change, with the prospect of a sudden global cooling also posing a danger.

The study found that winds from Arctic Siberia have been growing weaker, the conifer tree line has been retreating north, and there has been a steady rise in biodiversity in a general warming trend that continues today. It appears to have little to do with the increase in greenhouse gases which began with the industrial revolution, according to the researchers.


The distance from the Oort cloud to the interior of the Solar System, and two of the nearest stars, is measured in astronomical units. The scale is logarithmic; each indicated distance is ten times farther out than the previous distance. The red arrow indicates the location of the space probe Voyager 1, which will reach the Oort cloud in about 300 years [credit: NASA / JPL-Caltech]

Note that the Oort Cloud referred to in the article, although often discussed as though it exists, has to date never been directly observed, perhaps due to its supposed great distance from Earth.
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Stars and comets make unlikely dance partners, says Live Science.

Their gravitational partnership is one that astronomers have long suspected but have never seen — until now. For the first time, a Polish group has identified two nearby stars that seem to have plucked up their icy partners, swinging them into orbits around our sun.

The astronomers found the stellar duo after studying the movements of over 600 stars that came within 13 light-years of the sun. The new findings validate a theory born more than a half-century ago, and in doing so have also shown just how rare these stellar dances can be.

Out on the far edge of the solar system, hanging like wallflowers around the planetary dance floor, is the Oort Cloud.


The predicted ninth planet has so far proved elusive, with searches of 50 per cent of the sky in the range where it ‘should’ be having turned up nothing. But planetary theorists Mike Brown and Konstantin Batygin insist the evidence shows they are on the right track. Others talk of broken glass and fingerprints – shades of Sherlock Holmes.

Beyond Neptune, a handful of small worlds are moving in harmony.

Astronomers think they might be dancing to the tune of a third world lurking in the darkness, one that’s four times bigger than Earth and significant enough to be named our Solar System’s ninth planet.

Now they think they know exactly where to look for it, says Science Focus.


A recent review article on PNAS titled ‘Astronomical metronome of geological consequence’ by Linda Hinnov makes interesting reading for talkshoppers.

A Brief Retrospective
In geology, a reliable “metronome” in the geologic record with a sufficiently short repeat time would greatly enhance the resolving power of the geologic timescale. Astronomers recognized the potential importance of a dominant 405-ky cycle in Earth’s orbital eccentricity variation for supplying such a metronome (2, 3), leading geologists to turn to the stratigraphic record of astronomically forced paleoclimate change to search for this cycle. In fact, one of the first geological studies to describe 405-ky scale stratigraphic cycling was on the Triassic–Jurassic Newark Basin lacustrine strata (4, 5) recovered in the National Science Foundation-funded Newark Basin Coring Project, in which each of the prominent 60-m-thick McLaughlin cycles in the cored sequence was assigned a 412.885- ky periodicity based on a now-legacy analytical astronomical solution, BRE74/BER78 (6, 7). Since the 1990s, there have been dozens of reports for strong 405-ky scale cycles in stratigraphic sequences from around the world that appear to bear out this astronomical calculation (8).


An important new solar paper by Prof Valentina Zharkova and co-authors S. J. Shepherd, S. I. Zharkov & E. Popova  published in ‘Nature’ has incorporated the solar-planetary theory we’ve been researching and advancing here at the talkshop over the last decade. As well as further developing her previous double dynamo theory which now accounts for the last several millennium’s solar grand minima and maxima, she includes discussion of Fairbridge, Mackey, Shirley, Charvatova and Abreu et al’s work. Central to the new hypothesis is the motion of the Sun around the barycentre of the solar system, described as the Solar Inertial Motion [SIM].

Left plot: the example of SIM trajectories of the Sun about the barycenter calculated from 1950 until 210034. Right plot: the cone of expanding SIM orbits of the Sun35 with the top showing 2D orbit projections similar to the left plot. Here there are three complete SIM orbits of the Sun, each of which takes about 179 years. Each solar orbit consists of about eight, 22-year solar cycles35. The total time span is, therefore, three 179-year solar cycles31, or about 600 years. Source: Adapted from Mackey35. Reproduced with permission from the Coastal Education and Research Foundation, Inc

Following my discussion with her at dinner following her talk in London last year, Zharkova now agrees with us that the SIM induced by planetary motion affects sunspot production and solar activity levels.


Spiral galaxy NGC 5457 aka the Pinwheel Galaxy [image credit: European Space Agency & NASA]

OK, that’s not the original title of the article below – but it sounded a bit more interesting from a layman’s perspective 🙂

The rotation of stars in galaxies such as the Milky Way is puzzling, says

The orbital speeds of stars should decrease with their distance from the center of the galaxy, but in fact, stars in the middle and outer regions of galaxies have the same rotational speed.

This may be due to the gravitational effect of matter that we can’t see. But although researchers have been seeking it for decades, the existence of dark matter has yet to be definitively proven and we still don’t know what it might be made of.

With this in mind, the physicists Dmitri Ryutov, Dmitry Budker and Victor Flambaum have suggested that the rotational dynamics of galaxies might be explained by other factors. They hypothesize that the mass of photons, which are particles of light, might be responsible.


The BBC website hosts handy revision notes for our kids. Who vets the information? Some time ago I posted about their claim that melting sea ice raises the sea level, Archimedes be damned. Now we find that the BBC thinks that dinosaurs invented space travel and colonised Saturn’s moon Titan, forming it’s seas of methane after they died. The idiocy is unbounded.


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

This of course follows on from the very recent Part 1 of the model. Since Jupiter and Saturn are the dominant planets in our solar system, we can speculate that they may have a significant effect on the obliquity of smaller bodies. Or they may not – no-one knows, but we can look at possible evidence.
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Precession of the Jupiter-Saturn conjunction (J-S) was worked out by Kepler centuries ago, as shown in his diagram to the right.

‘As successive great conjunctions occur nearly 120° apart, their appearances form a triangular pattern. In a series every fourth conjunction returns after some 60 years in the vicinity of the first. These returns are observed to be shifted by some 7–8°’ – Wikipedia.


Earth’s Axial Tilt, or Obliquity [Credit: Wikipedia]

First let’s get the approximate target numbers for the model.

‘The inclination of Earth’s orbit varies with respect to the solar system’s invariant plane with a period of roughly 71000 years.
. . .
Taken in conjunction with the 26000-year spin-axis precession, the 71000-year orbit precession causes a 41000-year oscillation in the tilt of the earth’s axis, about plus or minus 1.3 degrees from its average value of 23.3 degrees. This number is not absolutely stable – it depends on the combined positions of all the planets through time.’

Astronomy: precession of Earth (Washington State University)
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Origin of the 100 kyr Glacial Cycle: eccentricity or orbital inclination?

‘Spectral analysis of climate data shows a strong narrow peak with period ~ 100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth’s orbit. The narrowness of the peak does suggest an astronomical origin; however the shape of the peak is incompatible with both linear and nonlinear models that attribute the cycle to eccentricity or (equivalently) to the envelope of the precession. In contrast, the orbital inclination parameter gives a good match to both the spectrum and bispectrum of the climate data.’

Richard A. Muller — University of California, Berkeley and
Gordon J. MacDonald — University of California, San Diego


Last Wednesday I attended the talk by Professor Valentina Zharkova hosted by the GWPF in London. She delivered a superb lecture including news of new work improving her model by including quadrupole magnetic parameters. In the Q & A session that followed, I got the opportunity to point up the connection between her model output and Rick Salvadors.

zharkova salvador models

I got a very positive response, including an invitation to collaborate on further work. We discussed this further over dinner, when I gave her a printed copy of Rick’s 2013 PRP paper.


The highly tilted orbit of Eris compared to the orbits of Ceres (light blue), Jupiter (maroon), Saturn (orange, Uranus (green), Neptune (blue), Pluto (olive, and MakeMake (red) [image credit: Fandom]

Could a ‘rogue’ star passing nearby have disturbed outer parts of the early solar system? Beyond Neptune things become somewhat different.

The outer reaches of our solar system harbor a number of mysterious features. Astrobites reports on whether a single stellar fly-by could help explain them all.

A star is born from the gravitational collapse of a cloud of gas and dust. Yet not all of the material ends up in the star, and instead forms a flat protoplanetary disk that surrounds the new star. Over time, the materials in this disk coalesce to form planets, moons, asteroids, and most other objects you might expect to find near a typical star.

Since protoplanetary disks are flat, the expectation is that all of the planets and objects orbiting a star that formed out of a protoplanetary disk should orbit on a single plane. So when we find stars with planets that orbit at multiple different inclinations, this raises questions.


The Parker solar probe is headed for space tomorrow. Best of luck to the mission team.

Our hypothesis that solar variation is affected by planetary motion, developed over the last 10 years here at the talkshop received a boost today when one of its main detractors, Anthony Watts, published an article declaring that solar cycle 24 is entering minimum.

I’ve left a comment there, something I rarely do since the debacle back in 2014 when Anthony and his sidekick Willis attacked our work and banned discussion of our solar-planetary theory. I’ll be interested to see if it passes moderation.


Here’s the plot I linked. It shows that Rick Salvador’s model is spot on track over the last 5 years.