Starship Asterisk*

neufer wrote:The artist is on the bridge among the people (not looking down from above) and perspective makes parallel lunar light beams radiate out.

Nitpicker wrote:
Looking at the observers' shadows, they do not appear to have a particularly consistent angle about them. And I also see people holding lanterns. So, it is also possible that the exact date is uncertain and the Moon was elsewhere, or the Moon was simply not full enough to be casting much light.

L. McNish wrote:I'm pretty sure Anthony Barreiro got it right. Given the angle the comet's tail makes with the horizon, I'd say it's a view to the west-southwest after sunset on approximately Christmas Eve 1680 (Gregorian calendar). The only time the Moon was to the "left" of the 1680 comet was after perihelion, and if it was just out of frame to the top left, this would account for the lighting and various shadow angles on the ground. The bright stars in the painting however, do not seem to agree with my simulation so I would suggest these were added later against the red sky. Both Venus and Mercury would also have been visible rising on the left from the horizon up towards the Moon, but these are also missing from the painting (also perhaps out of frame).

A very interesting picture by an artist of scientists performing real science outdoors at a special time of year with two churches to guide us to the date, time and location.

Larry McNish Calgary Centre of the Royal Astronomical Society of Canada

Chris Peterson wrote:
Statistics suggest this comet is not in an escape orbit.

http://en.wikipedia.org/wiki/Lies,_damned_lies,_and_statistics wrote:
<<"Lies, damned lies, and statistics" is a phrase describing the persuasive power of numbers, particularly the use of statistics to bolster weak arguments. It is also sometimes colloquially used to doubt statistics used to prove an opponent's point. Mark Twain popularized the saying in "Chapters from My Autobiography", published in the North American Review in 1906. "Figures often beguile me," he wrote, "particularly when I have the arranging of them myself; in which case the remark attributed to Disraeli would often apply with justice and force: 'There are three kinds of lies: lies, damned lies, and statistics.'" However, the phrase is not found in any of Disraeli's works and the earliest known appearances were years after his death.

The earliest instance of the phrase found in print dates to a letter written June 8, 1891, published June 13, 1891: "Sir,--It has been wittily remarked that there are three kinds of falsehood: the first is a 'fib,' the second is a downright lie, and the third and most aggravated is statistics. It is on statistics and on the absence of statistics that the advocate of national pensions relies....." Later, in October 1891, as a query in Notes and Queries, the pseudonymous questioner, signing as "St Swithin", asked for the originator of the phrase, indicating common usage even at that date. The pseudonym has been attributed to Eliza Gutch.

The phrase, as noted by Robert Giffen in 1892, was a variation on a phrase about three types of unreliable witnesses, a liar, a damned liar, and an expert: "An old jest runs to the effect that there are three degrees of comparison among liars. There are liars, there are outrageous liars, and there are scientific experts. This has lately been adapted to throw dirt upon statistics. There are three degrees of comparison, it is said, in lying. There are lies, there are outrageous lies, and there are statistics."

That phrase can be found in Nature in 1885, page 74 Nov 26, 1885: :"A well-known lawyer, now a judge, once grouped witnesses into three classes: simple liars, damned liars, and experts." A minute of the X Club meeting held on 5 December 1885, recorded by Thomas Henry Huxley, noted "Talked politics, scandal, and the three classes of witnesses—liars, d—d liars, and experts." Quoted in 1900 in Leonard Huxley's The Life and Letters of Thomas Henry Huxley.

neufer wrote:The Yarkovsky effect is a photon type rocket whose momentum contribution is quite weak due to the E/c relationship. That's O.K. for long term effects on meteoroids and small asteroids but not for short term effects on comets. The chemical rocket equivalent of cometary jets should be much more efficient (solar energy wise) in generating thrust.

Chris Peterson wrote:

neufer wrote:
A perihelion velocity increase of just 47 millimeters per second
is all that is required [for Comet ISON] to reach escape velocity

In the case of a sungrazer this tiny (47mm/s) perihelion velocity increase could come either from:

• 1) strong cometary (tail) jets near perihelion from a rotating cometary nucleus and/or
  
  2) a gravitational assist near perihelion from a Sun moving at ~13m/s in the anti-Jupiter direction.

The effects you mention can add energy to the orbit, but they can also remove it.

Chris Peterson wrote:
In addition, there are other effects such as Yarkovsky that can be significant (either adding or removing energy, depending on the direction the body is rotating).

Chris Peterson wrote:

neufer wrote:

Chris Peterson wrote:To be clear, it is likely this body remains in a closed solar orbit.

Your figuring is wrong on that matter.

I didn't do any figuring. I'm simply noting that only a few percent of comets with osculating eccentricities greater than 1 as they neared perihelion actually were in hyperbolic solar escape orbits. The odds are that this one will also be elliptical once it is well pass perihelion.

The effects you mention can add energy to the orbit, but they can also remove it. In addition, there are other effects such as Yarkovsky that can be significant (either adding or removing energy, depending on the direction the body is rotating).

The bottom line is we won't know if this body is in an escape orbit until months after perihelion, but the odds are against it.

neufer wrote:

Chris Peterson wrote:To be clear, it is likely this body remains in a closed solar orbit.

Your figuring is wrong on that matter.

Chris Peterson wrote:

neufer wrote:
While it takes only a small deflection to nullify an Oort cloud object's angular momentum...
how does the angular momentum get canceled out almost completely?

How are you figuring that the (orbital) angular momentum of the comet has changed significantly?

Chris Peterson wrote:

neufer wrote:
This will be the first pass of Comet ISON (C/2012 S1) and it has an eccentricity ~ 1.0000021.

To be clear, it is likely this body remains in a closed solar orbit.

Hence, a perihelion velocity increase of just 47 millimeters per second (= 188 m/s/4000)
is all that is required to reach escape velocity

In the case of a sungrazer this tiny (47mm/s) perihelion velocity increase could come either from:

• 1) strong cometary (tail) jets near perihelion from a rotating cometary nucleus and/or
  
  2) a gravitational assist near perihelion from a Sun moving at ~13m/s in the anti-Jupiter direction.

neufer wrote:1681: October 28 – A London woman is publicly flogged for the crime of "involving herself in politics."

Ann wrote:
Aye, but imagine being alive (however briefly) at that time and see spectacular comets and asteroids painting fantastic light tracks in the sky!!!

• 1681: The last dodo bird is killed.
  
  1681: July 1 – Oliver Plunkett, Roman Catholic Primate
  of Ireland, falsely convicted of treason, is hanged,
  drawn and quartered at Tyburn, London.
  
  1681: October 28 – A London woman is publicly flogged
  for the crime of "involving herself in politics."

Ann wrote:Aye, but imagine being alive (however briefly) at that time and see spectacular comets and asteroids painting fantastic light tracks in the sky!!!

Nitpicker wrote: Aye, how we've gained since the Late Heavy Bombardment:
http://en.wikipedia.org/wiki/Late_Heavy_Bombardment

geckzilla wrote:I'm glad I live in the 2000's instead of the 1600's, but still... to be able to see comets over a city. For all that we've gained, we've still lost a little.

Anthony Barreiro wrote:
If we're looking southwest during evening dusk on Saturday 28 December, 1680, the light of the Moon, approaching first quarter, would account for the shadows on the snow-covered ground. The comet is conjuncting Venus! (This conjunction might account for the popularity of cross-staffs). The stars don't match up very well, but maybe Verschuier just put some random stars in for effect. According to his wikipedia article he was known for painting ships and landscapes, maybe he just wasn't very careful about creating a star chart.

• The cross-staffs might make more sense if it was 'Eerste Kerstdag' the 25th of December.

http://www.jwwerner.com/history/Comet.html wrote:

[b][color=#0000FF]The Great Comet of 1680 as seen from Nuremburg.[/color][/b]

---

This is what the first Dutch settlers of Esopus, New York, saw in the sky over 300 years ago! Excerpt from The History of Kingston, by Marius Schoonmaker, 1888, at page 70:

On the 9th of December 1680, there appeared an extraordinary comet, which caused very great consternation throughout the province, with forebodings of dreadful happenings and divine punishments. It is described, in a letter dated January 1st, 1681, as having "appeared in the Southwest on the ninth of December last, about two o'clock in the afternoon, fair sunshine weather, a little above the sun, which takes its course more northerly, and was seen the Sunday night [Dec. 15, NS], right after about twilight, with a very fiery tail or streamer in the west, to the great astonishment of all spectators, and is now seen every night with clear weather. Undoubtedly, God threatens us with dreadful punishments if we do not repent." The letter then suggested the propriety of proclaiming a day of humiliation and prayer.
...........................................................................
One more “first hand” account of the Comet as seen from Scotland! Attributed to The Reverend Robert Law(approx 1624-1689). Law was a minister during the tumultuous “Restoration Period” of Scottish history and author of The Memorable Things that Fell Out within this Island of Brittain from 1638 to 1684.): ‘December 10 [Dec. 20, NS], being Fryday, 1680, after sun-sett, there appeared in the west a comet, having a large broad and great streamer coming from it, the lyke was never seen or read of, and continued till the 16th or 17th day of January, growing smaller and smaller to it’s end;’

Stinky Old Man wrote:

ta152h0 wrote:I am not a person who was given the appreciation of art as my mother ( RIP ) tried so hard to do so I always question how art and science can benefit each other. Science to art is easy but the reverse may be questionable. This APOD makes the latter more plausible.

Earth without art is literally just "eh"

http://en.wikipedia.org/wiki/Eusebio_Francisco_Kino wrote:
<<Eusebio Francisco Kino, (10 August 1645 – 15 March 1711) was a Jesuit priest whose Exposisión astronómica de el cometa (Mexico City, 1681) on the Great Comet of 1680 is among the earliest scientific treatises published by a European in the New World. This publication was later the subject of a sonnet by the noted colonial nun and poetess of New Spain, Sor (Sister) Juana Inés de la Cruz.

Kino's was the son of Franz Kühn (or Francesco Chini) and he was educated in Innsbruck, Austria. He taught mathematics in Ingolstadt, he received Holy Orders as a priest on 12 June 1677. Although Kino wanted to go to the Orient, he was sent to New Spain. Due to travel delays while crossing Europe, he missed the ship on which he was to travel and had to wait a year for another ship. While waiting in Cadiz, Spain, he wrote some observations, done during late 1680 and early 1681, about his study of a comet (later known as Kirch's comet), which he subsequently published upon arriving in Mexico.

Father Kino enjoyed making model ships out of wood. His knowledge of maps and ships led him to believe that Mexican Indians could easily access Baja California by sea, a view taken with skepticism by missionaries in Mexico City. When Kino proposed and began making a boat that would be pushed across the Sonoran Desert to the Mexican west coast, a controversy arose, as many of his co-missionaries began to question Kino's faculties. However, Kino was able to prove that Baja California is not an island by leading an overland expedition there.

Kino opposed the slavery and compulsory hard labor in the silver mines that the Spaniards forced on the native people. In 1965, a statue of Kino was donated to the United States Capitol's National Statuary Hall collection, one of two statues representing Arizona. In John Steinbeck's novel, The Pearl, it is implied the protagonist is named after the missionary.>>

ta152h0 wrote:I am not a person who was given the appreciation of art as my mother ( RIP ) tried so hard to do so I always question how art and science can benefit each other. Science to art is easy but the reverse may be questionable. This APOD makes the latter more plausible.