Posts Tagged ‘planetary theory’

Planetary theory lives on, even if it now has to nod towards trace gases in the atmosphere to be in fashion with the times.

Scientists have long posited that periodic swings in Earth’s climate are driven by cyclic changes in the distribution of sunlight reaching our surface, says

This is due to cyclic changes in how our planet spins on its axis, the ellipticity of its orbit, and its orientation toward the sun—overlapping cycles caused by subtle gravitational interplays with other planets, as the bodies whirl around the sun and by each other like gyrating hula-hoops.

But planetary paths change over time, and that can change the cycles’ lengths. This has made it challenging for scientists to untangle what drove many ancient climate shifts.



ASTROBIOLOGY NASA picked this article from the Many Worlds website, and by doing so endorsed the writer’s apparent belief in ‘heat-trapping gases’. But the “thought experiment” the science meeting was engaging in did not seem to include any reference to Nikolov and Zeller’s Universal Theory of Climate, which could have helped them out considerably.

What would happen if you switched the orbits of Mars and Venus? Would our solar system have more habitable worlds?

It was a question raised at the “Comparative Climatology of Terrestrial Planets III”; a meeting held in Houston at the end of August, writes Elizabeth Tasker.


Saturn from the Cassini orbiter [image credit: NASA]

Weird compared to some theories, perhaps – but observations can trump theories, of course. Is it too weird to ask if the planet’s rings, extending outwards from the equator, and its axis-aligned magnetic field could be related phenomena?

Some of the last data from the Cassini mission reveals more structure in Saturn’s magnetic field, but still no answer as to how it formed, says

NASA’s Cassini mission—with Imperial kit on board—took a series of daring dives between the planet and its inmost ring in September 2017 before burning up in the planet’s atmosphere.


Credit: NASA

Meet ‘The Goblin’. This body’s maximum distance from the Sun is a massive 2300 times further out than Earth’s.

A newly spotted dwarf planet, 2015 TG387, adds to the mounting evidence that an unseen super-Earth prowls the edge of the solar system, reports Cnet.

Astronomers have found a small object far beyond Pluto that orbits the sun in a lonely, oblong loop, a discovery that supports the notion of a larger, more distant planet — often referred to as Planet X — wandering the edge of our solar system.


NASA mission to Jupiter’s
trojan asteroids

Could evidence from a specific binary asteroid pair upset existing planetary theories? ‘The Jupiter trojans, commonly called Trojan asteroids or just Trojans, are a large group of asteroids that share the planet Jupiter’s orbit around the Sun.’ – Wikipedia. There are over a million of these, inhabiting two oval-shaped zones based around what are known as the Lagrangian points L4 and L5 of Jupiter’s orbit (see animation below).

Scientists at Southwest Research Institute (SwRI) studied an unusual pair of asteroids and discovered that their existence points to an early planetary shake-up in our solar system.

These bodies, called Patroclus and Menoetius [see flyby 6 in the graphic], are targets of NASA’s upcoming Lucy mission to the Trojan asteroids. They are around 70 miles wide and orbit around each other as they collectively circle the Sun.


Solar system cartoon [NASA]

If a planet – assuming it exists – is very far away, extremely faint, could be almost anywhere, and is barely moving relative to its background (maybe one degree every few decades), then however large it may be the chances of finding it any time soon are not great.

Astronomers think that Planet Nine exists at the edge of the Solar System, says the Tech Times.

Here’s one possible reason why the body remains elusive despite circumstantial evidence that it exists beyond planet Neptune.


Three of Saturn’s moons — Tethys, Enceladus and Mimas — as seen from NASA’s Cassini spacecraft [image credit: NASA/JPL]

This is a comparison of the orbital patterns of Saturn’s four inner moons with the four exoplanets of the Kepler-223 system. Similarities pose interesting questions for planetary theorists.

The first four of Saturn’s seven major moons – known as the inner large moons – are Mimas, Enceladus, Tethys and Dione (Mi,En,Te and Di).

The star Kepler-223 has four known planets:
b, c, d, and e.

When comparing their orbital periods, there are obvious resonances (% accuracy shown):
Saturn: 2 Mi = 1 Te (> 99.84%) and 2 En = 1 Di (> 99.87%)
K-223: 2 c = 1 e (>99.87%) and 2 b = 1 d (> 99.86%)


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.


Top row: artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth.
[Image credit: NASA/JPL-CALTECH]

Talkshop analysis of some of the data follows this brief report from Astrobiology at NASA.

A team of researchers has provided new information about putative planets in the outer regions of the TRAPPIST-1 system. Currently, seven transiting planets have been identified in orbit around the ultra cool red dwarf star. The scientists determined the lower bounds on the orbital distance and inclination (within a range of masses) of planets that could be beyond the seven inner planets.


Here we find a match between the orbit numbers of Jupiter, Saturn and Uranus and see what that might tell us about certain patterns in the solar system.

715 U = 60072.044 years
2040 S = 60072.895 years
5064 J = 60072.282 years
Data source: Nasa/JPL – Planets and Pluto: Physical Characteristics

The Jupiter-Saturn part of the chart derives directly from this earlier Talkshop post:
Why Phi? – Jupiter, Saturn and the de Vries cycle


Room for one more? [image credit: NASA]

There’s a suspicion of confirmation bias, or seeing what you wanted to see, in stories like this. But we’ll look for any merits in the ideas anyway. Claims that Planet 9 can’t hide much longer haven’t proved correct so far.

Observations made a thousand years ago could help modern scientists find the theoretical “Planet Nine” in the outer reaches of the solar system, says Live Science.

The far reaches of the outer solar system may be home to an icy giant — a hypothetical planet scientists have dubbed “Planet Nine.”

Meanwhile, archives back on Earth are home to dozens of medieval records documenting the passage of comets through the heavens. Now, two researchers from Queen’s University Belfast in Northern Ireland are hoping to use these old scrolls and tapestries to solve the modern astronomical mystery of Planet Nine.


The planet Mercury, as imaged by the MESSENGER spacecraft [Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington]

More theoretical speculations about Mercury’s origins, arising from what is now believed to be evidence of historical volcanic activity.

Mercury is the closest planet to the sun, but far from being a dull cinder of a world, it has instead turned out to be a real eye opener for geologists, says

Among the revelations by NASA’s MESSENGER probe, which first flew past Mercury in 2008 and orbited it between 2011 and 2015, is the discovery of a hundred or so bright red spots scattered across the globe. Now they are at last being named.

Although they appear more yellow-orange than red on the accompanying colour-enhanced images, they are the reddest features on Mercury, a planet that looks dull and grey on unenhanced images.


Solar wind at Mars [image credit:]

The researchers say ‘the solar wind likely only had a very small direct effect on the amount of Mars atmosphere that has been lost over time.’ This makes them suspect that ‘a magnetic field is not as important in shielding a planet’s atmosphere as the planet’s gravity itself.’ It was always hard to see how the magnetic shield theory worked when Venus with its dense atmosphere has little magnetism.

The Red Planet’s low gravity and lack of magnetic field makes its outermost atmosphere an easy target to be swept away by the solar wind, but new evidence from ESA’s Mars Express spacecraft shows that the Sun’s radiation may play a surprising role in its escape, reports

Why the atmospheres of the rocky planets in the inner solar system evolved so differently over 4.6 billion years is key to understanding what makes a planet habitable.


Triton: Neptune’s odd moon

Posted: January 27, 2018 by oldbrew in Astrophysics, exploration
Tags: ,

Neptune and Triton (below) [credit: NASA]

Triton has the second-biggest ratio of moon-to-planet to Neptune, being only lower than the ratio between Earth and its own Moon. As well as having over 400 times the mass of any other Neptunian moon, Triton has some peculiarities about its environment, including the fact that it orbits backward to Neptune’s rotation and seems to have undergone a huge melt in the past, as explains. NASA believes it has similarities to Pluto. In 2006, a model published in Nature suggested Triton was originally a member of a binary system that orbited the sun.

Triton is the largest of Neptune’s moons. Discovered in 1846 by British astronomer William Lassell — just weeks after Neptune itself was found — the moon showed some strange characteristics as astronomers learned more about it.


Jupiter-sized exoplanet [Wikipedia]

It seems the planetary structure of our solar system is an oddity compared to most of the exoplanetary systems so far discovered. On the other hand it’s easier to find planets close to their stars than those a long way away, so what is known so far might not be giving us the whole picture.

An international research team led by Université de Montréal astrophysicist Lauren Weiss has discovered that exoplanets orbiting the same star tend to have similar sizes and a regular orbital spacing, says

This pattern, revealed by new W. M. Keck Observatory observations of planetary systems discovered by the Kepler Telescope, could suggest that most planetary systems have a different formation history than the solar system.

Thanks in large part to the NASA Kepler Telescope, launched in 2009, many thousands of exoplanets are now known. This large sample allows researchers to not only study individual systems, but also to draw conclusions on planetary systems in general.


Although the author appears sold on the idea of trace gases controlling the temperature of planetary atmospheres, the discussion about planets and water is worth a look. The answer to the question may depend on more powerful space telescopes like the James Webb.

Wherever we find water on Earth, we find life writes Elizabeth Tasker at Many Worlds.

It is a connection that extends to the most inhospitable locations, such as the acidic pools of Yellowstone, the black smokers on the ocean floor or the cracks in frozen glaciers.

This intimate relationship led to the NASA maxim, “Follow the Water”, when searching for life on other planets.

Yet it turns out you can have too much of a good thing.


From left, Mercury, Venus, Earth and Mars. [Credit: Lunar and Planetary Institute]

The planetary theory aspect appears a bit later, but first a brief review of some relevant details.

In this Talkshop post: Why Phi? – a triple conjunction comparison we said:
(1) What is the period of a Jupiter(J)-Saturn(S)-Earth(E) (JSE) triple conjunction?
JSE = 21 J-S or 382 J-E or 403 S-E conjunctions (21+382 = 403) in 417.166 years (as an average or mean value).

(2) What is the period of a Jupiter(J)-Saturn(S)-Venus(V) (JSV) triple conjunction?
JSV = 13 J-S or 398 J-V or 411 S-V conjunctions (13+398 = 411) in 258.245 years (as an average or mean value).

Since JSV = 13 J-S and JSE = 21 J-S, the ratio of JSV:JSE is 13:21 exactly (in theory).

As these are consecutive Fibonacci numbers, the ratio is almost 1:Phi or the golden ratio.

Pluto probe

Uncertainty abounds here. Scientists expected –173° Celsius but ‘the probe found temperatures closer to –203° — with no obvious explanation.’ Perhaps there is a place where enlightenment could be found, if they cared to look.

Meanwhile the ‘gas only’ theory is under pressure [sic] again, as Pluto’s atmosphere apparently defies expectations.

Pluto may be the only place in the solar system whose atmosphere is kept cool by solid hazes, not warmed by gas, says Science News.

Blame Pluto’s haze for the dwarf planet’s unexpected chilliness. Clusters of hydrocarbons in the atmosphere radiate heat back into space, keeping the dwarf planet cool, a new study suggests.


Saturn’s moon Janus

Cassini maintains its reputation for surprises right to the end. It’s the ‘moon resonances’ that maintain ring stability, but with a new twist.

For three decades, astronomers thought that only Saturn’s moon Janus confined the planet’s A ring – the largest and farthest of the visible rings.

But after poring over NASA’s Cassini mission data, Cornell astronomers now conclude that the teamwork of seven moons keeps this ring corralled, as explains.

Without forces to hold the A ring in check, the ring would keep spreading out and ultimately disappear.


Where is Planet 9? [credit: NASA]

Planetary theorists say super-Earths are commonly found in other planetary systems, but missing – so far – in our solar system. The evidence seems to be mounting, so is it just a case of tracking one down?

It might be lingering bashfully on the icy outer edges of our solar system, hiding in the dark, but subtly pulling strings behind the scenes: stretching out the orbits of distant bodies, perhaps even tilting the entire solar system to one side, says NASA’s Jet Propulsion Laboratory.

If a planet is there, it’s extremely distant and will stay that way (with no chance — in case you’re wondering — of ever colliding with Earth, or bringing “days of darkness”). It is a possible “Planet Nine” — a world perhaps 10 times the mass of Earth and 20 times farther from the sun than Neptune.

The signs so far are indirect, mainly its gravitational footprints, but that adds up to a compelling case nonetheless.