Starship Asterisk*

Doum wrote:
At first i tought it was possible for it to have been in the Oort cloud and it encounter planet nine wich make it come toward us with a little above our system's escape velocity. But since it was dryed i suppose its not possible. just a tought.

http://www.syfy.com/syfywire/breaking-have-astronomers-discovered-our-first-interstellar-visitor-note-not-aliens wrote:
Have astronomers discovered our first interstellar visitor?
by Phil Plait

<<If there’s another planet in our solar system orbiting far, far beyond Neptune, and the asteroid started somewhere nearby (that is, as part of our solar system since the start) and passed close to this planet, it could get a kick in velocity and get flung down towards us at higher speed. However, a lot of things have to line up for this to happen so the odds on this are incredibly low, so low I’d put them at essentially 0. But I’d be remiss not to at least mention it.>>

Chris Peterson wrote:

HiYoSilver wrote:What if the visitor is not a visitor, but was once part of the solar system, was flung out, and is just re-entering?

If it had been flung out but remained in a closed orbit (so that it could reenter), we'd see an eccentricity of slightly less than one, not significantly more than one (1.19). This is almost certainly a first time visitor that originated elsewhere.

neufer wrote:

Chris Peterson wrote:

BDanielMayfield wrote:
Its speed also suggests an energetic expulsion rather than a gentle release.

Actually, its speed is low for an interstellar object. But that tells us nothing about the speed of its ejection, only about the relative speed of its parent system with respect to our own.

Which begs the question of why we didn't first observe interstellar asteroid/comets coming in at two to three times that speed since their interception rate should be some two to three times higher (and their rapid motion might have been more pronounced).

Chris Peterson wrote:The fact that this one was traveling only a little above our system's escape velocity suggests a nearby star which is traveling in a similar orbit to our own.

BDanielMayfield wrote:

Chris Peterson wrote:The fact that this one was traveling only a little above our system's escape velocity suggests a nearby star which is traveling in a similar orbit to our own.

Dang! This very thought (that it came from a nearby system) occurred to me earlier, but I didn’t express it, due to questioning common sense explanations. :| :wink: :lol2:

MarkBour wrote:
It would be interesting to view this in terms of the galactic plane. If A/2017 U1 came from Lyra, I think that maybe we "caught up" to it in our rotation around the galactic plane.

https://en.wikipedia.org/wiki/Milky_Way#Sun.E2.80.99s_location_and_neighborhood wrote:
<<The orbital speed of the Solar System about the center of the Milky Way is approximately 220 km/s. The general direction of the Sun's Galactic motion is towards the star Vega near the constellation of Hercules, at an angle of roughly 60 sky degrees to the direction of the Galactic Center. The Sun's orbit about the Milky Way is expected to be roughly elliptical with the addition of perturbations due to the Galactic spiral arms and non-uniform mass distributions. In addition, the Sun passes through the Galactic plane approximately 2.7 times per orbit. This is very similar to how a simple harmonic oscillator works with no drag force (damping) term.>>

MarkBour wrote:
And its resulting trajectory may mean that the Sun has ejected it from the galactic plane.
But perhaps it does not have the velocity to get very far from the plane.

Does someone have a rendering of the encounter in these terms?

HiYoSilver wrote:
I'm encouraged that the quality of discussion here includes phrases such as "This is almost certainly..." and "... appears to have... " Rather than conclusive statements. Open mindedness seems essential in any scientific statement.

https://www.gutenberg.org/files/2431/2431-h/2431-h.htm wrote:

• IS SHAKESPEARE DEAD?
  by MARK TWAIN

We set down the five known facts by themselves, on
a piece of paper, and numbered it "page 1"; then on fifteen hundred other
pieces of paper we set down the "conjectures," and "suppositions," and
"maybes," and "perhapses," and "doubtlesses," and "rumors," and
"guesses," and "probabilities," and "likelihoods," and "we are permitted
to thinks," and "we are warranted in believings," and "might have beens,"
and "could have beens," and "must have beens," and "unquestionablys,"
and "without a shadow of doubts"--and behold!

_Materials_? Why, we had enough to build a biography of Shakespeare!

neufer wrote:

MarkBour wrote:And its resulting trajectory may mean that the Sun has ejected it from the galactic plane.
But perhaps it does not have the velocity to get very far from the plane.

Does someone have a rendering of the encounter in these terms?

The asteroid will be sent out from the Sun at a relative velocity of 26 km/s and at an angle of 36°
below the Galactic plane for a relative vertical velocity = -15 km/s [= 26 sin(-36°)].

However the Sun is currently moving at a velocity of 220 km/s and at an angle of 18°
above the Galactic plane for an absolute vertical velocity = 67 km/s [= 220 sin(18°)].

Hence the absolute vertical velocity of the asteroid is just 45 km/s [= 67 - 15]
: thus less than the Sun and like the Sun confined to the disk.

neufer wrote:

HiYoSilver wrote:
I'm encouraged that the quality of discussion here includes phrases such as "This is almost certainly..." and "... appears to have... " Rather than conclusive statements. Open mindedness seems essential in any scientific statement.

https://www.gutenberg.org/files/2431/2431-h/2431-h.htm wrote:

• IS SHAKESPEARE DEAD?
  by MARK TWAIN

We set down the five known facts by themselves, on
a piece of paper, and numbered it "page 1"; then on fifteen hundred other
pieces of paper we set down the "conjectures," and "suppositions," and
"maybes," and "perhapses," and "doubtlesses," and "rumors," and
"guesses," and "probabilities," and "likelihoods," and "we are permitted
to thinks," and "we are warranted in believings," and "might have beens,"
and "could have beens," and "must have beens," and "unquestionablys,"
and "without a shadow of doubts"--and behold!

_Materials_? Why, we had enough to build a biography of Shakespeare!

saturno2 wrote:
I think that this Asteroid ( or Comet) A/2017 U1
enters and leaves for Solar System without being
destroyed is due to its high speed 26 Km/s,
faster than spacecraft Voyagers

BDanielMayfield wrote:

neufer wrote:

MarkBour wrote:And its resulting trajectory may mean that the Sun has ejected it from the galactic plane.
But perhaps it does not have the velocity to get very far from the plane.

Does someone have a rendering of the encounter in these terms?

The asteroid will be sent out from the Sun at a relative velocity of 26 km/s and at an angle of 36°
below the Galactic plane for a relative vertical velocity = -15 km/s [= 26 sin(-36°)].

However the Sun is currently moving at a velocity of 220 km/s and at an angle of 18°
above the Galactic plane for an absolute vertical velocity = 67 km/s [= 220 sin(18°)].

Hence the absolute vertical velocity of the asteroid is just 45 km/s [= 67 - 15]
: thus less than the Sun and like the Sun confined to the disk.

I trust that your trig is sound, but your subtraction could use some work.

BDanielMayfield wrote:
Still, 52 km/s is less than 67, so your conclusion is verified.

HiYoSIlver wrote:

neufer wrote:

HiYoSilver wrote:
I'm encouraged that the quality of discussion here includes phrases such as "This is almost certainly..." and "... appears to have... " Rather than conclusive statements. Open mindedness seems essential in any scientific statement.

https://www.gutenberg.org/files/2431/2431-h/2431-h.htm wrote:

• IS SHAKESPEARE DEAD?
  by MARK TWAIN

We set down the five known facts by themselves, on
a piece of paper, and numbered it "page 1"; then on fifteen hundred other
pieces of paper we set down the "conjectures," and "suppositions," and
"maybes," and "perhapses," and "doubtlesses," and "rumors," and
"guesses," and "probabilities," and "likelihoods," and "we are permitted
to thinks," and "we are warranted in believings," and "might have beens,"
and "could have beens," and "must have beens," and "unquestionablys,"
and "without a shadow of doubts"--and behold!

_Materials_? Why, we had enough to build a biography of Shakespeare!

But does it answer the question? Plus, was the biography really an autobiography? Good old Sam. Good old Neufer. Okay, maybe Neufer isn't so old, but Sam certainly is, in a subjective temporal kind of way, etc., etc.

• I'm "as old as dirt" : born under Aquarius in 1946.

https://en.wikipedia.org/wiki/21P/Giacobini%E2%80%93Zinner wrote:

---

<<Comet Giacobini–Zinner is a periodic comet in the Solar System. It is the parent body of the Draconids meteor shower. It was discovered by Michel Giacobini (from Nice, France), who observed the comet in the constellation of Aquarius on December 20, 1900. During its apparitions, Giacobini–Zinner can reach about the 8th magnitude, but in 1946 it underwent a series of outbursts that made it as bright as 5th magnitude. Giacobini–Zinner was the target of the International Cometary Explorer spacecraft, which passed through its plasma tail on September 11, 1985.>>

https://en.wikipedia.org/wiki/Mark_Twain wrote:
<<Samuel Langhorne Clemens (November 30, 1835 – April 21, 1910) was born shortly after an appearance of Halley's Comet, and he predicted that he would "go out with it" as well; he died the day after the comet returned.>>

https://en.wikipedia.org/wiki/Draconids wrote:
<<The October Draconids are a meteor shower whose parent body is the periodic comet 21P/Giacobini-Zinner. They are named after the constellation Draco, where they seemingly come from. The 1933 and 1946 Draconids had Zenithal Hourly Rates of thousands of meteors visible per hour, among the most impressive meteor storms of the 20th century.>>

https://en.wikipedia.org/wiki/Orionids wrote:
<<The Orionid meteor shower, usually shortened to the Orionids, is the most prolific meteor shower associated with Halley's Comet. The Orionids are so-called because the point they appear to come from, called the radiant, lies in the constellation Orion, but they can be seen over a large area of the sky. Orionids are an annual meteor shower which last approximately one week in late October. In some years, meteors may occur at rates of 50–70 per hour.>>

https://en.wikipedia.org/wiki/International_Cometary_Explorer wrote:

---

<<The International Cometary Explorer (ICE) spacecraft was launched August 12, 1978, into a heliocentric orbit. ICE became the first spacecraft to visit a comet, passing through the plasma tail of comet Giacobini-Zinner within about 7,800 km of the nucleus on September 11, 1985. ICE transited between the Sun and Comet Halley in late March 1986, when other spacecraft were near the comet on their early-March comet rendezvous missions. ICE flew through the tail; its minimum distance to the comet nucleus was 28 million kilometres. For comparison, Earth's minimum distance to Comet Halley in 1910 was 20.8 million kilometres.>>

https://en.wikipedia.org/wiki/Is_Shakespeare_Dead%3F wrote:
<<Is Shakespeare Dead? is a short, semi-autobiographical posthumous 1910 work by American humorist Mark Twain. In the book, Twain expounds the view that Shakespeare of Stratford was not the author of the canon, and lends tentative support to the Baconian theory. The book opens with a scene from his early adulthood, where he was trained to be a steamboat pilot by an elder who often argued with him over the controversy. Twain compares the believers in Shakespeare to adherents of Arthur Orton and Mary Baker Eddy. We get our beliefs at second hand, he explains, "we reason none of them out for ourselves. It is the way we are made." Twain has set a trap—an elaborate joke at the expense of what he scornfully refers to as the "Reasoning Race." He is satirizing the need to win an argument when it is virtually impossible to convince anyone to change sides in almost any debate.>>

neufer wrote: ...

https://en.wikipedia.org/wiki/Is_Shakespeare_Dead%3F wrote:<<Is Shakespeare Dead? is a short, semi-autobiographical posthumous 1910 work by American humorist Mark Twain. ...>>

MarkBour wrote:

neufer wrote: ...

https://en.wikipedia.org/wiki/Is_Shakespeare_Dead%3F wrote:<<Is Shakespeare Dead? is a short, semi-autobiographical posthumous 1910 work by American humorist Mark Twain. ...>>

WAS SAMUEL CLEMENS DEAD?
Anyone who can write an autobiographical posthumous work is a top-notch humorist in my book.

MarkBour wrote:

neufer wrote: ...

https://en.wikipedia.org/wiki/Is_Shakespeare_Dead%3F wrote:<<Is Shakespeare Dead? is a short, semi-autobiographical posthumous 1910 work by American humorist Mark Twain. ...>>

WAS SAMUEL CLEMENS DEAD?
Anyone who can write an autobiographical posthumous work is a top-notch humorist in my book.

• It was published posthumously.

https://en.wikipedia.org/wiki/Mark_Twain wrote:
<<Twain's last work was his autobiography, which he dictated and thought would be most entertaining if he went off on whims and tangents in non-chronological order. Some archivists and compilers have rearranged the biography into a more conventional form, thereby eliminating some of Twain's humor and the flow of the book. The first volume of the autobiography, over 736 pages, was published by the University of California in November 2010, 100 years after his death, as Twain wished. It soon became an unexpected best seller, making Twain one of a very few authors publishing new best-selling volumes in the 19th, 20th, and 21st centuries.>>

Kinematics of the Interstellar Vagabond A/2017 U1 wrote: Eric Mamajek
(Submitted on 31 Oct 2017)
The initial Galactic velocity vector for the recently discovered hyperbolic asteroid A/2017 U1 is calculated for before its encounter with our solar system. When the velocity is compared to the local stars, A/2017 U1 can be easily ruled out as co-moving with any of the dozen nearest systems, i.e. it does not appear to be associated with any local exo-Oort clouds (most notably that of the Alpha Centauri triple system). The object's velocity is within 5 km/s of the mean Galactic velocity of the stars in the solar neighborhood (<25 pc), so its velocity would appear to be typical for that of a body whose velocity was drawn from the Galactic velocity distribution of the local stars. These calculations strengthen the interpretation that A/2017 U1 has a distant extrasolar origin, but not among the very nearest stars.

BDanielMayfield wrote:This here ‘roid ain’t from ‘round here.

Kinematics of the Interstellar Vagabond A/2017 U1 wrote: Eric Mamajek
(Submitted on 31 Oct 2017)
The initial Galactic velocity vector for the recently discovered hyperbolic asteroid A/2017 U1 is calculated for before its encounter with our solar system. When the velocity is compared to the local stars, A/2017 U1 can be easily ruled out as co-moving with any of the dozen nearest systems, i.e. it does not appear to be associated with any local exo-Oort clouds (most notably that of the Alpha Centauri triple system). The object's velocity is within 5 km/s of the mean Galactic velocity of the stars in the solar neighborhood (<25 pc), so its velocity would appear to be typical for that of a body whose velocity was drawn from the Galactic velocity distribution of the local stars. These calculations strengthen the interpretation that A/2017 U1 has a distant extrasolar origin, but not among the very nearest stars.

MargaritaMc wrote:

BDanielMayfield wrote:This here ‘roid ain’t from ‘round here.

Kinematics of the Interstellar Vagabond A/2017 U1 wrote: Eric Mamajek
(Submitted on 31 Oct 2017)
The initial Galactic velocity vector for the recently discovered hyperbolic asteroid A/2017 U1 is calculated for before its encounter with our solar system. When the velocity is compared to the local stars, A/2017 U1 can be easily ruled out as co-moving with any of the dozen nearest systems, i.e. it does not appear to be associated with any local exo-Oort clouds (most notably that of the Alpha Centauri triple system). The object's velocity is within 5 km/s of the mean Galactic velocity of the stars in the solar neighborhood (<25 pc), so its velocity would appear to be typical for that of a body whose velocity was drawn from the Galactic velocity distribution of the local stars. These calculations strengthen the interpretation that A/2017 U1 has a distant extrasolar origin, but not among the very nearest stars.

Here's the URL for that paper by Mamajek
https://arxiv.org/abs/1710.11364

BDanielMayfield wrote: Thanks MargaritaMc. (I have no idea why the quote function didn’t work for me, except possibly that I’m using an IPad. I made several attempts to fix it to no avail.)

Bruce

[url]https://arxiv.org/abs/1710.11364[/url]

[quote][/quote]

Like this

BDanielMayfield wrote:... (I have no idea why the quote function didn’t work for me, except possibly that I’m using an IPad. I made several attempts to fix it to no avail.) ...

bystander wrote:

BDanielMayfield wrote:... (I have no idea why the quote function didn’t work for me, except possibly that I’m using an IPad. I made several attempts to fix it to no avail.) ...

Your problem was not in the <quote> tags but in your selection of quote marks. BBcode does not recognize the open and close double quote marks (“not this”) but only the dual purpose double quote ("but this").

BDanielMayfield wrote:

bystander wrote:

BDanielMayfield wrote:... (I have no idea why the quote function didn’t work for me, except possibly that I’m using an IPad. I made several attempts to fix it to no avail.) ...

Your problem was not in the <quote> tags but in your selection of quote marks. BBcode does not recognize the open and close double quote marks (“not this”) but only the dual purpose double quote ("but this").

Thanks bystander. Since the IPad has only one quote key and selects the open and close quote symbols automatically this will be a recurring pain ...

Chris wrote: Try Settings - General - Keyboards - Smart Punctuation Off.

The visit of the interstellar interloper 1I/2017 U1, recently spotted streaking through the Solar System, gives the people of Earth their first chance to study up close an object from another planetary system. In a study carried out with the WIYN telescope at Kitt Peak National Observatory and the Nordic Optical Telescope in the Canary Islands, astronomers find that despite its foreign origins, U1 is familiar in appearance — its size, rotation, and color are similar to that of asteroids in our Solar System. Its familiar appearance supports the long-held view that our Solar System once ejected its own flotilla of such messengers out into interstellar space. ...