1950 was a vintage year for Cometary science and pseudoscience.
In April 1950, after 8 rejections, Immanuel Velikovsky [amongst many other things] introduced a new generation to the long established science of the Hydrocarbon Comet.
In 1950, after eight publishing houses rejected the Worlds in Collision manuscript, it was finally published by Macmillan, which had a large presence in the academic textbook market.
https://en.wikipedia.org/wiki/Immanuel_Velikovsky
The book postulated that around the 15th century BCE, Venus was ejected from Jupiter as a comet or comet-like object, and passed near Earth (an actual collision is not mentioned)… Venus must be rich in petroleum gases, and hydrocarbons.
https://en.wikipedia.org/wiki/Worlds_in_Collision
The resemblance of the cometary spectrum to the spectrum of hydrocarbons in the Geissler tube lends great plausibility to this view.
1911 Encyclopædia Britannica – 1911 – Volume 6 – Comet
https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/CometSwan bands are a characteristic of the spectra of carbon stars, comets and of burning hydrocarbon fuels.
https://en.wikipedia.org/wiki/Swan_bands
In March 1950 Fred Whipple “visualized” his breathtakingly incoherent “conglomerate of ices” Comets containing “unobserved” compounds.
The model predicts a large excess of unobserved hydrides, H2O, NH3, and CH4 molecules, as compared to the observed CO+, C2, and CN.
A Comet Model. II. Physical Relations for Comets and Meteors.
F L Whipple – Harvard College Observatory
Astrophysical Journal – Vol. 113 – P .464 – May 1951
http://newburyastro.org.uk/whatsup/news/20150111/comet-lovejoy.html
In January 1950 Jan Oort invoked his academic needs must prerogative and magically conjured up [out of thin air] an unobserved “cloud” of 100,000,000,000 Comets around the Sun.
The sun must be surrounded by a general cloud of comets with a radius of this order, containing about 1011 comets of observable size, the total mass of the cloud is estimated to be of the order of 1/10 to 1/100 of that of the earth.
The Structure of The Cloud of Comets Surrounding The Solar System and A Hypothesis Concerning Its Origin – J H Oort
Bulletin of the Astronomical Institutes of the Netherlands – Vol XI #408 – 13 Jan 1950
Unsurprisingly, different scientists see the size of this unseen Cloud very differently.
From a score of well-observed orbits it is shown that the “new” long-period generally come from regions about 50,000 and 150,000 A.U. distance.
The Structure of The Cloud of Comets Surrounding The Solar System and A Hypothesis Concerning Its Origin – J H Oort
Bulletin of the Astronomical Institutes of the Netherlands – Vol XI #408 – 13 Jan 1950The inner edge of the main part of the Oort Cloud could be as close as 1,000 AU from our sun. The outer edge is estimated to be around 100,000 AU.
Voyager Goes Interstellar (Artist Concept) – NASA/JPL-Caltech – 2013-09-12
https://photojournal.jpl.nasa.gov/catalog/PIA17046The Oort cloud… a theoretical cloud… between 50,000 and 200,000 AU…
Jan Oort also invented the Interstellar Rollerball Lottery.
Occasionally, an anonymous Star [at least 4 light years distant from the Sun] is allocated to choose one lucky winner from the 100,000,000,000 cohort of “fresh” Comets in the Cloud.
The lucky winner of the Interstellar Rollerball Lottery is then “carried” towards the Sun.
Through the action of the stars fresh comets are continually being carried from this cloud into the vicinity of the sun.
The Structure of The Cloud of Comets Surrounding The Solar System and A Hypothesis Concerning Its Origin – J H Oort
Bulletin of the Astronomical Institutes of the Netherlands – Vol XI #408 – 13 Jan 1950
https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs
I guess mainstream scientists consider inventing a Cometary Cloud coupled with an Interstellar Rollerball Lottery more credible than an Inner Solar System source of Comets.
Worlds in Collision is a book written by Immanuel Velikovsky and first published April 3, 1950. The book postulated that around the 15th century BCE, Venus was ejected from Jupiter as a comet or comet-like object, and passed near Earth (an actual collision is not mentioned).
https://en.wikipedia.org/wiki/Worlds_in_Collision
See: https://malagabay.wordpress.com/2017/09/20/the-atomic-comet-the-great-snowball-of-1950/
And more believable than an Interstellar or Intergalactic source of Comets.
Firstly, the plan view of the Earth’s orbit reveals that Aphelion [which occurs in early July] aligns with M54 at the “core” of the Sagittarius Dwarf Spheroidal Galaxy.
Secondly, the side elevation [aka cross section] of the Earth’s orbit reveals that the Sun [and hence the Solar System] is “travelling in a polar orbit (i.e. an orbit passing over the Milky Way’s galactic poles)” and this trajectory clearly suggests the Sagittarius Dwarf Spheroidal Galaxy wins the Our Galaxy designation competition.
See: https://malagabay.wordpress.com/2016/06/01/lawler-alignments-galactic-roller-coaster/
The potential for interstellar Cometary travel is enhanced by their self-propelling properties.
Heading into Perihelion the “violent gas and dust jets” of Comet Halley produce reverse thrust.
… as Halley approaches the Sun, it expels jets of sublimating gas from its surface, which knock it very slightly off its orbital path. These orbital changes cause delays in its perihelion of four days, average.
However, after Perihelion, Comet Halley powers away from the Sun as it’s “violent gas and dust jets” produce an enhanced after burn thrust that’s clearly demonstrated by it’s increased visual magnitude.
Due to the retrograde orbit, it has one of the highest velocities relative to the Earth of any object in the Solar System.
The 1910 passage was at a relative velocity of 70.56 km/s (157,838 mph or 254,016 km/h).
The enhanced after burn thrust was quite pronounced after Perihelion on 9.48 Feb 1986.
Data derived from: Comet Halley: India Observations – T Chandrasekhar
Indian Journal of Radio & Space Physics – Vol 17 – Dec 1988
However, by about 0.75 AU from the Sun the enhanced after burn thrust had dissipated.
Why Comet Halley decelerated near the orbital distance of Venus [0.723 AU] is open to debate.
Nevertheless, interstellar objects are seen “passing through the Solar System” [Hat Tip: CW].
A/2017 U1 (previously C/2017 U1 (PANSTARRS)) is an apparently interstellar object passing through the Solar System.
It was discovered on an extremely hyperbolic orbit by Robert Weryk on October 18, 2017 by the Pan-STARRS telescope, when the object was 0.2 AU (30,000,000 km; 19,000,000 mi) from Earth. Initially thought to be a comet, it was reclassified as an asteroid a week later.
Based on the first 2 weeks of observations, 2017 U1’s orbital eccentricity is 1.1922 ± 0.00268, the highest of any known object in the Solar System.
The previous record holder was C/1980 E1 with an eccentricity of 1.057.
The high eccentricity both inbound and outbound indicates that it is not gravitationally bound to the Solar System and is presumably an interstellar object.
…
This is possibly the first example of an interstellar object, appearing to originate from the constellation Lyra, with a hyperbolic excess velocity of 26 km/s with respect to the Sun.
…
Assuming it is a rock with an albedo of 10%, it would be roughly 160 meters in diameter.
The latest interstellar visitor is said to be coloured “red”.
Spectrum taken by the 4.2 meter William Herschel Telescope on October 25 showed the object was red like Kuiper belt objects.
https://en.wikipedia.org/wiki/A/2017_U1
Personally, I wonder whether this “red” object is closer to a “ruby red” colour.
A carbon star is typically an asymptotic giant branch star, a luminous red giant, whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide, which consumes all the oxygen in the atmosphere, leaving carbon atoms free to form other carbon compounds, giving the star a “sooty” atmosphere and a strikingly ruby red appearance.
https://en.wikipedia.org/wiki/Carbon_star
See: https://malagabay.wordpress.com/2017/10/05/the-atomic-comet-carbon-cousins/
I also wonder whether the modern mainstream mindset has the intellectual capacity to overcome its primitive and superstitious veneration of the unseen, the unobservable and the intangible.
Sadly, there’s little hope when the modern mainstream mindset so warmly welcomes the secure embrace of an intellectual straitjacket that encourages it’s inmates to proudly project their scientific sins onto others.
Velikovsky’s work is frequently cited as a canonical example of pseudoscience and has been used as an example of the demarcation problem.
Such is the surreal state of Settled Science.
MalagaBay 
nextexx.com/venus-james-p-hogan/
cadxx
Carbon shock for comet researchers…
Report: Observations of a comet’s first passage through the solar system reveal unexpected secrets
November 10, 2017 by Nicholas A. Veronico
Comets originating from the Oort Cloud, like Comet C/2012 K1, remain unaffected by the thermal heating and radiation processing of the Sun. The pristine nature of these comets can preserve surface materials making them ideal targets for observing gas and dust particle composition.
“Comet C/2012 K1 is a time capsule of the early solar system’s composition”
. . .
By analyzing these silicate emissions and comparing them to thermal models, the researchers determined that the coma’s dust grains are large and comprised predominately of carbon rather than crystalline silicate. This composition challenges existing theoretical models of how Oort cloud comets form. [bold added]
Read more at: http://phys.org/news/2017-11-comet-passage-solar-reveal-unexpected.html
Thanks for the update….
This comet or asteroid from beyond the solar system is a bit different…
From the WIYN observations, no coma—a nebulous envelope of dust and gas created when comets heat up as they pass near the sun—is apparent. The WIYN team also failed to see a tail, the signature feature of a comet.
. . .
It also has a reddish tinge and a low albedo, suggesting 1I/2017 U1 lacks the coating of ice that many comets acquire as they spend most of their time in cold storage in the outer reaches of the solar system.
Read more at: http://phys.org/news/2017-11-images-strange-solar-visitor-mystery.html
More details on the ‘flying cigar’: colleagues determined that the object was about 400m long, rapidly rotating and subject to dramatic changes in brightness.
These changes in brightness were the clue to ‘Oumuamua’s bizarre shape.
. . .
“We also found that it had a reddish colour, similar to objects in the outer Solar System, and confirmed that it is completely inert, without the faintest hint of dust around it,” Dr Meech said.
These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over long periods of time.
http://www.bbc.co.uk/news/science-environment-42053634
The ‘dramatic changes in brightness’ are not explained AFAIK.
Like an old coin flipping in space. Edge on dull, full face bright. Tossing satellites seen after sundown appear like that, blinking.
More comet info…’quirky 45P doesn’t quite match any comet studied so far.’
NASA telescope studies quirky comet 45P
November 22, 2017
http://phys.org/news/2017-11-nasa-telescope-quirky-comet-45p.html
Now we have confirmation that Europa, like Enceladus has a liquid water ocean inside it.
https://www.npr.org/2018/05/14/610357799/icy-moon-of-jupiter-spews-water-plumes-into-space
The only prediction that water sources would be found abundantly in bodies throughout the Solar System was Immanuel Velikovsky’s 1940s argument that a proto-Saturn star had gone Nova following a virtual collision with or close interaction with Jupiter within the memory of human existence on earth.
Pingback: Parallax Proxy | MalagaBay