Cassini captures wave structure in Saturn rings

Image credit: NASA

We now know that Saturn’s rings share a process with spiral galaxies, and the unique co-orbital pattern of two of its moons get some attention.

This view from NASA’s Cassini spacecraft shows a wave structure in Saturn’s rings known as the Janus 2:1 spiral density wave, reports Phys.org.

Resulting from the same process that creates spiral galaxies, spiral density waves in Saturn’s rings are much more tightly wound.

In this case, every second wave crest is actually the same spiral arm which has encircled the entire planet multiple times. This is the only major density wave visible in Saturn’s B ring.

Unique study tests fundamental laws of physics

As the Talkshop reaches the milestone of 5 million visits, do we hear echoes of Scotty of Star Trek fame: ‘Ye cannae change the laws of physics’? Does fundamental mean universal – or could some ‘laws’ depend on where you look in the universe? Meanwhile Tallbloke is boldly going…somewhere… 😎

A study that will ‘test our understanding of how the Universe works, particularly outside the relatively narrow confines of our planet’ is being undertaken by an international team of researchers led by the University of Leicester, reports Phys.org.

The research probes whether the fundamental laws of physics are the same everywhere in the universe.

In their new study, the Leicester-led team assesses whether these laws are the same within the hot, dense conditions in the atmosphere of a dying white dwarf star as here on Earth.

Variable sunshine— researchers explain why our Sun’s brightness fluctuates

Sunspots [image credit: NASA]

One of the authors of the research says: “The results of our study show us that we have identified the governing parameters in our model”. Both climate and exoplanet research could benefit from the findings.

The Sun shines from the heavens, seemingly calm and unvarying. In fact, it doesn’t always shine with uniform brightness, but shows dimmings and brightenings, reports Phys.org.

Two phenomena alone are responsible for these fluctuations: the magnetic fields on the visible surface and gigantic plasma currents, bubbling up from the star’s interior.

A team headed by the Max Planck Institute for Solar System Research in Göttingen reports this result in today’s issue of Nature Astronomy. For the first time, the scientists have managed to reconstruct fluctuations in brightness on all time scales observed to date – from minutes up to decades.

The moving Martian bow shock

Credit: NASA

Among other findings, solar EUV [extreme ultraviolet radiation] turns out to be a greater planetary force than expected in this new research. Also the bow shock is greater the nearer Mars gets to the Sun during its orbit.

As the energetic particles of the solar wind speed across interplanetary space, their motion is modified by objects in their path. A study, based on data from ESA’s Mars Express orbiter, has thrown new light on a surprising interaction between the planet Mars and supersonic particles in the solar wind, reports Phys.org.

Scientists have long been aware that a feature known as a bow shock
forms upstream of a planet – rather like the bow of a ship, where the water is slowed and then diverted around the obstacle.

The bow shock marks a fairly sharp boundary where the solar wind slows suddenly as it begins to plough into a planet’s magnetosphere or outer atmosphere.

In the case of Mars, which does not generate a global magnetic field and has a thin atmosphere, the main obstacle to the solar wind is the ionosphere – a region of electrically charged particles in its upper atmosphere.

Voyager spacecraft still reaching for the stars and setting records after 40 years

These two 1977 vintage machines really are ‘cosmic overachievers’ as this Phys.org report calls them. Voyager 1 reached interstellar space in 2012, but the last science instrument is not due to be switched off until 2030.

Humanity’s farthest and longest-lived spacecraft, Voyager 1 and 2, achieve 40 years of operation and exploration this August and September.

Despite their vast distance, they continue to communicate with NASA daily, still probing the final frontier. Their story has not only impacted generations of current and future scientists and engineers, but also Earth’s culture, including film, art and music.

Each spacecraft carries a Golden Record of Earth sounds, pictures and messages. Since the spacecraft could last billions of years, these circular time capsules could one day be the only traces of human civilization.

Going Up: Jupiter’s Auroras Get Weirder Than Ever

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Jupiter is living up to its billing as a ‘planet on steroids’.
http://www.theguardian.com/science/2016/jun/04/probe-jupiter-juno

Planet Pailly

Last week, the Juno mission flew over Jupiter’s Great Red Spot and sent back some spectacular close-ups. But I’m not ready to talk about that. Not yet. I’m still catching up on the Juno news from two months ago.

Toward the end of May, NASA released a ton of fresh data from Juno, including new information about Jupiter’s auroras. Astro-scientists had previously known about two sources contributing to these auroras: the solar wind and the Io plasma torus. Now Juno may have discovered a third.

As Juno flew over Jupiter’s poles, it detected electrically charged particles flying up.

I can’t emphasize enough how weird this is. I wanted to write about it right away, but I held off doing this post because I was sure I must have misunderstood what I was reading.

Auroras are caused by electrically charged particles accelerated down toward a planet’s magnetic poles. These…

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Earth’s water explained by gas giant gluttony

Niagara Falls [image credit: Saffron Blaze / Wikipedia]

The author of this theory says “Jupiter and Saturn’s growth naturally pollutes the inner Solar System with water-rich planetesimals. In my mind the mechanism is very clear”. The theory does seem to bear a resemblance to this summary from the Hans Rickman Uppsala Astronomical Observatory.

Water on Earth, Mars and everywhere within the inner Solar System can be traced back to the rapid waist-expanding growth of Jupiter and Saturn, which knocked inwards a local population of icy planetesimals, as Sci-News reports.

This is according to a new model, which could also explain the current makeup of our modern asteroid belt.

Whilst Earth is often described as the blue marble, with over 70% of its surface covered in oceans, seas, rivers and lakes, water actually makes up less than 0.1% of our planet by mass.

Data from NASA’s Solar Dynamics Observatory offer clues about sun’s coronal irradiance

Credit: NASA

Extreme ultraviolet radiation (EUV) is perhaps an aspect of solar activity that gets less attention than it should. The authors make the interesting point in their introduction to the research article that ‘Although the total solar irradiance at Earth varies very little, the relative variance in the EUV is as large as the mean irradiance. This EUV light interacts with Earth’s thermosphere and stratosphere and may affect climate in a “top-down” process in regions such as northern Europe’.

A pair of researchers with Aberystwyth University in the U.K. has used data from NASA’s Solar Dynamics Observatory to learn more about how the sun’s corona behaves over differing stages of its 11-year cycle, reports Bob Yirka at phys.org.

In their paper published on the open access site Science Advances, Huw Morgan and Youra Taroyan describe attributes of the sun they observed over time and what they discovered about the “quiet corona” and its possible impact on us back here on Earth.

Major breakthrough in solar-planetary theory: Barycentre research vindicated

As long time regulars at the Talkshop know, our ongoing research into the links between planetary motion and solar variation has occasionally borne fruit in unexpected ways. The ‘shorthand’ for the sum of all planetary vectors is the Sun’s motion with respect to the barycentre of the solar system. This is the path the Sun is forced to follow by the ongoing evolution of the motion of all the planets. We have found various tantalising near-correlations between aspects of this motion and solar activity levels suggestive of some kind of mechanistic linkage.

We have been ridiculed for years by the WUWT wankers among others for working on this theory. Various other solar researchers have attempted ‘disproofs’ of a planetary effect on solar activity too. They all tell us the planets are “too small and too far away to affect the Sun”.

Last year, we featured a post concerning the work of Shepherd, Zharkov and Zharkova, who have been coming at the solar variation problem from another angle. They resolved the solar-hemispheric components of the solar polar fields into two separate curves, representing shallow and deep solar ‘dynamos’.

Combining the curves together produces a good representation of changing solar activity levels. Their prediction is, like ours from our planetary model, for a big solar slowdown extending through the middle decades of this century. The mainstream climate scientists tried to get the press release revoked…

Extending a new Lunar thermal model, Part III: Modelling the Moon at various rotation rates

Overview

More than a year after “Part II” of a guest post from Talkshop contributor ‘Galloping Camel’ on the Moon’s equatorial temperature here is “Part III”.  Peter actually sent this to Tim Channon last year, but Tim became to ill to deal with it and forgot to throw it my way. In current discussion of Ned and Karl’s new paper, the issue of planetary surface temperature variation due to speed of rotation arose. Ned thinks it makes no difference. Peter’s model says it does, so now is a good time for discussion, as this impacts theoretical estimates for the temperature of ‘Earth with no atmosphere’.

Modeling the Moon

It has been claimed that the GHE (Greenhouse Effect) is 33 Kelvin because the Earth’s average temperature is 288 K compared to a temperature of 255 K assumed for an “Airless Earth”.  The Diviner LRO showed that the Moon’s average temperature is 197.3 K which makes one wonder how an estimate based on impeccable mathematics could be so wrong?   Vasavada et al. published a paper in 2012 that mentioned a one-dimensional model of the Moon’s regolith.  As I was unable to obtain details of this model I attempted to replicate it using Quickfield, a powerful FEA (Finite Element Analysis) program.  Results obtained using my model were published here.

Foundations of Greenhouse Theory Challenged by New Analysis of Solar System Observations

Back in late 2011, the Talkshop splashed the story on a ‘Unified Theory of Climate’  developed by PhD physicists Ned Nikolov and Karl Zeller. They set out to show that the ‘greenhouse effect’ is not a phenomenon arising out of the absorption and reemission of outgoing long-wave radiation by the atmosphere (as thought for 190 years), but is a form of compression heating controlled by solar radiation and the total atmospheric pressure at the Earth’s surface. Pressure is in turn a product of the gas mass contained in a column of air above a unit surface area, and the planet’s gravitational effect on that mass.

It’s been a long and treacherous road involving many revisions and refinements of the original study. On several occasions the manuscript was rejected unread, but Ned and Karl have finally got their greatly improved and expanded paper published. This latest version is a tour de force strengthened by the rigors of criticism from an army of peer reviewers at several journals along the way.

Using dimensional analysis (a classical technique for inferring physically meaningful relationships from measured data), they show that the long-term global equilibrium surface temperature of bodies in the solar system as diverse as Venus, the Moon, Earth, Mars, Titan and Triton can accurately be described using only two predictors: the mean distance from the Sun and the total atmospheric surface pressure. This type of cross-planetary analysis using vetted NASA observations has not been conducted by any other authors. It represents the first and only attempt in the history of climate science to assess Earth’s surface temperature in the context of a cosmic physical continuum defined by actual planetary-scale observations. The result is a new insight that planetary climates are independent of the infrared optical depth of their atmospheres arising from their composition, and that the long-wave ‘back radiation’ is actually a product of the atmospheric thermal effect rather than a cause for it.

Trappist-1: seven-planet resonance chain confirmed

Much media attention on this new paper this week. Is there a surprise lurking in the details now that the orbit period of the seventh planet has been confirmed?.

What the numbers in the diagram show is the orbits per planet in a fixed period (top row), the conjunctions per planet pair in the same period (second row), and the ratios that represents (third row).

The number of conjunctions of any two planets is the difference between the two orbit numbers in a given period, which in this case is equivalent to just under 1446 Earth days (see data below).

Apart from the obvious symmetry of the ratios, something else arose from the science paper.

First magnetic field detected “outside” of a galaxy

Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the largest astronomical project in the world –
Magellanic Clouds near top of image [credit: NASA / Ames]

It’s unimaginably vast: astronomers say ‘this structure is a 75,000 light-year long filament of gas and dust’. Trying to separate out the effects of gravity and magnetism here should be an interesting challenge.

A magnetic field appears to span the space between the Large and Small Magellanic Clouds, the two dwarf galaxies being consumed by our Milky Way Galaxy, reports Sky & Telescope via Sott.net.

For stargazers in the Northern Hemisphere, it’s easy to forget that the Milky Way is actively consuming two dwarf galaxies. Those in the Southern Hemisphere have a front row seat to watch our galaxy wreak havoc on the Large and Small Magellanic Clouds (LMC and SMC).

But there’s more to the story — the dwarfs are not only gravitationally interacting with the Milky Way but with each other as well.

Mysterious Tabby’s Star dims again: observations needed

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Fascinating stuff – here we go again…

https://tallbloke.wordpress.com/2016/12/21/mystery-of-alien-megastructure-star-testing-astronomers-creativity/

The Lined Wolf

Let’s face it: KIC 8462852 (also Tabby’s Star or Boyajian’s Star) is a weird star. Since its unusual light variations were discovered by citizen scientists using data of NASA’s Kepler space telescope in September 2015 many, many things have been written by professional and amateur astronomers, science communicators and “searchers of mysteries”, as an interesting hypothesis about its behavior was that it could be signs of activity associated with intelligent extraterrestrial life constructing a Dyson swarm. Of course, this just run wild in general media, and many astronomers since them have been asked by journalist to talk about “Mysterious Tabby’s Star”.

In particular, this theme soon captured the attention of some of my friends at the Instituto de Astrofísica de Canarias (IAC, Spain), as they weekly produce an amazing ~2h science communication podcast Coffee Break: Señal y Ruido (Signal to noise). I’m proud to participate in this podcast from…

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Astrophysicists find that planetary harmonies around TRAPPIST-1 save it from destruction: Why Phi?

Exoplanets up to 90 times closer to their star than Earth is to the Sun.

Excellent – we outlined this ‘resonance chain’ (as they have now dubbed it) in an earlier post here at the Talkshop [see ‘Talkshop note’ in the linked post for details].

When NASA announced its discovery of the TRAPPIST-1 system back in February it caused quite a stir, and with good reason says Phys.org.

Three of its seven Earth-sized planets lay in the star’s habitable zone, meaning they may harbour suitable conditions for life.

But one of the major puzzles from the original research describing the system was that it seemed to be unstable.

“If you simulate the system, the planets start crashing into one another in less than a million years,” says Dan Tamayo, a postdoc at U of T Scarborough’s Centre for Planetary Science.

KAM theorem, and its application to the stability of the Solar system. Why Phi?

I’m not expecting much discussion of this post, I don’t understand it either, though I have run across KAM before in another context, and eventually some light may dawn that illuminates some relationship with our phi-solar system dynamics work. I’ll just leave it here for now so it doesn’t get lost. One random synchrony is that Gabriella Pinzari is at the same university as Nicola Scafetta. Maybe we can get him interested enough to talk to her about our theory.

The following message is a guest post by Boris Khesin. Boris summarizes the wonderful talk given by Gabriella Pinzari at the workshop.  –Jim Colliander

Gabriella Pinzari (30min talk) described her joint result with her advisor Luigi Chierchia on a recently found fix for the famous KAM theorem, or rather for its application to the stability of the Solar system.

Namely, the original KAM theorem in Arnold’s 1963 paper claimed the persistence of the Liouville tori for perturbations of integrable systems under some nondegeneracy assumption – some determinant must be nonzero. This was a perfectly correct statement proved in the paper. But Arnold applied it to the Solar system without properly checking that for that system the determinant is indeed nonzero. (More precisely, Arnold checked the non-degeneracy condition for the first nontrivial case, the planar three-body problem, and claimed that this could extend to the general case: spatial, arbitrary n.) However, it turned out to be identically zero in the spatial case.

Ian Wilson: Help Needed to Solve an Interesting Lunar Puzzle

Astrophysicist Ian Wilson has emailed me to ask for a brainstorming session at the talkshop to assist him. Ian writes:

“I was wondering if you or your colleagues (e.g. oldbrew) could help me work out the solution to the following lunar puzzle”

The Conundrum

The diagram below shows the Perigee of the lunar orbit pointing at the Sun at 0.0 days. In addition, the diagram shows the Perigee of the lunar orbit once again pointing at the Sun after one Full Moon Cycle (FMC) = 411.78443025 days. It takes more than 1.0 sidereal year (= 365.256363004 days) for the Perigee to realign with the Sun because of the slow pro-grade (clockwise) precession of the lunar line-of-apse once every 8.85023717 sidereal years.

1.0 FMC falls short of 15 anomalistic months (= 413.31824817 days) by 1.53381792 days (= 1.5117449198^O). During these 1.5117449198 days the Perigee end of the lunar line-of-apse rotates by 0.17081406^O in a prograde direction, producing an overall movement of the line-of-apse (red line) of 1.34093086^O (= 1.5117449198^O – 0.17081406^O) with respect to the Earth-Sun line (blue line).

NASA to launch 12 satellites to Venus

The satellites won’t land as the surface pressure – 92 times that of Earth – and heat of Venus would destroy them. Instead they will look for a ‘mysterious substance’ thought to be lurking in its atmosphere.

NASA has spent $3.6 million to build 12 small satellites to explore the planet Venus in search of a mysterious substance that absorbs half the planet’s light, reports The Daily Caller.

The CubeSat UV Experiment (CUVE) mission will launch the satellites to investigate atmospheric processes on Venus. The 12 satellites vary in size. One is less than four inches across and weighs a few ounces. Another weighs 400 pounds.

Research team finds a universal law for galactic systems

The research team thinks its results are ‘difficult to understand in terms of dark matter’, reports Phys.org. The study was earlier reported here.

The distribution of normal matter precisely determines gravitational acceleration in all common types of galaxies, a team led by Case Western Reserve University researchers reports.

The team has shown this radial acceleration relation exists in nearby high-mass elliptical and low-mass spheroidal galaxies, building on last year’s discovery of this relation in spiral and irregular galaxies.

This provides further support that the relation is tantamount to a new natural law, the researchers say.

EmDrive: UK scientist claims ‘new physics’ explains galaxy rotation and theoretical space propulsion

Dwarf galaxy NGC 5264 [image credit: ESA/Hubble]

Dark matter faces quantised inertia. One of these ideas must leave town, or the galaxies, it seems.

British physicist Dr Mike McCulloch, who previously used quantised inertia to explain how the controversial electromagnetic space propulsion technology EmDrive works, says that he has new evidence showing his theory can also explain galaxy rotation, which is one of physics’ biggest mysteries, as the IB Times reports.

McCulloch, a lecturer in geomatics at Plymouth University’s school of marine science and engineering, says he now has even more evidence that his “new physics theory” about quantised inertia works, and that it makes it possible to explain why galaxies are not ripped apart without using theory of dark matter.

One of the biggest problems in physics today is how galaxies rotate. Galaxies are collections of millions of stars swirling around, and galaxies spin so rapidly that their centrifugal force should cause them fly apart, as there isn’t enough visible matter in them to hold them together by the force of gravity.