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New Extrasolar Visitor
#1

New Extrasolar Visitor
Astronomers are currently tracking a comet named Borisov (C/2019 Q4). It's interesting because the object's orbit has a perihelion of just over 2 AU, an eccentricity of 3.7, and an inclination of 43 degrees. Eccentricity is a measure of how elliptical an object's orbit is. An eccentricity of more than 1 indicates that the object is not bound to the body that it orbits and it's on an escape trajectory. In Borisov's case it's moving some 30.7 km/s too fast to stay in the solar system. While comets are occasionally ejected from the solar system by getting a gravitational assist from a planet, Borisov's high speed and high inclination preclude this explanation. Borisov is a visitor from outside our solar system and will be leaving again. Borisov has begun developing a tail, which will provide astronomers with a lot of information about it's chemical composition as it fluoresces.
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#2

New Extrasolar Visitor
Our prime minister is called Borisov... I wouldn't mind him being ejected from the solar system Modest
“We drift down time, clutching at straws. But what good's a brick to a drowning man?” 
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#3

New Extrasolar Visitor
Interesting. We can't yet travel to distance stars but dead matter has no problem doing so. I wonder what the odds are of a comet strike to our planet from a comet not in orbit around our sun.
"Talk nonsense, but talk your own nonsense, and I'll kiss you for it. To go wrong in one's own way is better than to go right in someone else's. 
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#4

New Extrasolar Visitor
(09-14-2019, 05:23 PM)Mark Wrote: Interesting.  We can't yet travel to distance stars but dead matter has no problem doing so.  I wonder what the odds are of a comet strike to our planet from a comet not in orbit around our sun.

I've heard that the odds of our planet being hit by extra-solar debris is on the order of 1,000,000,000:1. If those odds are correct, then it's likely already happened. Possibly more than once.
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#5

New Extrasolar Visitor
Waiting for Rama I.
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#6

New Extrasolar Visitor
As if we don't have enough comets of our own to worry about.
Robert G. Ingersoll : “No man with a sense of humor ever founded a religion.”
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#7

New Extrasolar Visitor
(09-14-2019, 05:23 PM)Mark Wrote: Interesting.  We can't yet travel to distance stars but dead matter has no problem doing so.

Well, you could travel to another star. You'd just have to do it as dead matter. We have the technology to get your dessicated corpse to Alpha Centauri in a few million years.

Quote:I wonder what the odds are of a comet strike to our planet from a comet not in orbit around our sun.

Pretty low at the moment. If we passed close enough to another star for the sun to pass through their Oort Cloud then we could get all sorts of debris flung around. That's likely happened already and some of our comets might not be original components of our solar system.
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#8

New Extrasolar Visitor
I'll bet that the profs at my alma mater will be posing this as a test problem to the class. I remember having the computation of an earth-orbit crossing asteroid's orbital trajectory as a test problem in my solar system astrophysics class. In this case, that comet isn't even in the plane of the ecliptic, so maybe the possible impact/near approach will only nudge a planet out of that orbital plane by some small amount. Wobble, wobble, wobble! Maybe the moon's libration will be corrected. PFF.
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#9

New Extrasolar Visitor
(09-14-2019, 05:06 PM)Paleophyte Wrote: Astronomers are currently tracking a comet named Borisov (C/2019 Q4). It's interesting because the object's orbit has a perihelion of just over 2 AU, an eccentricity of 3.7, and an inclination of 43 degrees. Eccentricity is a measure of how elliptical an object's orbit is. An eccentricity of more than 1 indicates that the object is not bound to the body that it orbits and it's on an escape trajectory. In Borisov's case it's moving some 30.7 km/s too fast to stay in the solar system. While comets are occasionally ejected from the solar system by getting a gravitational assist from a planet, Borisov's high speed and high inclination preclude this explanation. Borisov is a visitor from outside our solar system and will be leaving again. Borisov has begun developing a tail, which will provide astronomers with a lot of information about it's chemical composition as it fluoresces.

Is it expected to become naked-eye visible as it passes through the solar system?
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#10

New Extrasolar Visitor
(09-15-2019, 12:11 PM)Cavebear Wrote:
(09-14-2019, 05:06 PM)Paleophyte Wrote: Astronomers are currently tracking a comet named Borisov (C/2019 Q4). It's interesting because the object's orbit has a perihelion of just over 2 AU, an eccentricity of 3.7, and an inclination of 43 degrees. Eccentricity is a measure of how elliptical an object's orbit is. An eccentricity of more than 1 indicates that the object is not bound to the body that it orbits and it's on an escape trajectory. In Borisov's case it's moving some 30.7 km/s too fast to stay in the solar system. While comets are occasionally ejected from the solar system by getting a gravitational assist from a planet, Borisov's high speed and high inclination preclude this explanation. Borisov is a visitor from outside our solar system and will be leaving again. Borisov has begun developing a tail, which will provide astronomers with a lot of information about it's chemical composition as it fluoresces.

Is it expected to become naked-eye visible as it passes through the solar system?

Nobody knows. It depends a lot on composition and size, which are both complete mysteries. If it's large and has a lot of hydrogen ice, or something similarly volatile, then it might become naked to the visible eye.
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#11

New Extrasolar Visitor
(09-15-2019, 04:38 PM)Paleophyte Wrote:
(09-15-2019, 12:11 PM)Cavebear Wrote:
(09-14-2019, 05:06 PM)Paleophyte Wrote: Astronomers are currently tracking a comet named Borisov (C/2019 Q4). It's interesting because the object's orbit has a perihelion of just over 2 AU, an eccentricity of 3.7, and an inclination of 43 degrees. Eccentricity is a measure of how elliptical an object's orbit is. An eccentricity of more than 1 indicates that the object is not bound to the body that it orbits and it's on an escape trajectory. In Borisov's case it's moving some 30.7 km/s too fast to stay in the solar system. While comets are occasionally ejected from the solar system by getting a gravitational assist from a planet, Borisov's high speed and high inclination preclude this explanation. Borisov is a visitor from outside our solar system and will be leaving again. Borisov has begun developing a tail, which will provide astronomers with a lot of information about it's chemical composition as it fluoresces.

Is it expected to become naked-eye visible as it passes through the solar system?

Nobody knows. It depends a lot on composition and size, which are both complete mysteries. If it's large and has a lot of hydrogen ice, or something similarly volatile, then it might become naked to the visible eye.

Well I understand THAT!  But usually, astronomers have an idea on expected visibility of approaching comets.  But yeah, new comet.  Got it.  Sorry.
I just believe in one less deity than most people.
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#12

New Extrasolar Visitor
(09-15-2019, 04:54 PM)Cavebear Wrote:
(09-15-2019, 04:38 PM)Paleophyte Wrote:
(09-15-2019, 12:11 PM)Cavebear Wrote: Is it expected to become naked-eye visible as it passes through the solar system?

Nobody knows. It depends a lot on composition and size, which are both complete mysteries. If it's large and has a lot of hydrogen ice, or something similarly volatile, then it might become naked to the visible eye.

Well I understand THAT!  But usually, astronomers have an idea on expected visibility of approaching comets.  But yeah, new comet.  Got it.  Sorry.

Hakuna matata. Most of the brightness estimates for approaching comets tend to be rubbish anyway. The distance from Earth to the comet is about the only known variable unless it's a repeat offender. Brightness estimates for comets that we're observing for the first time are commonly out by a couple of orders of magnitude due to variations in outgassing, which is heavily influenced by composition and internal structure.

In this case we can't even make reasonable assumptions about a lot of those variables the way we might for a comet from our backyard. Hell, we don't even know what size it is. It might be a 10 km wide ball of loosely bound hydrogen ice that'll boil like all blazes or it might he a house-sized block of solid water ice that'll barely produce a coma and tail. Early results suggest that it's behaving a lot like a typical Oort Cloud object though.
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#13

New Extrasolar Visitor
(09-15-2019, 09:44 PM)Paleophyte Wrote:
(09-15-2019, 04:54 PM)Cavebear Wrote:
(09-15-2019, 04:38 PM)Paleophyte Wrote: Nobody knows. It depends a lot on composition and size, which are both complete mysteries. If it's large and has a lot of hydrogen ice, or something similarly volatile, then it might become naked to the visible eye.

Well I understand THAT!  But usually, astronomers have an idea on expected visibility of approaching comets.  But yeah, new comet.  Got it.  Sorry.

Hakuna matata. Most of the brightness estimates for approaching comets tend to be rubbish anyway. The distance from Earth to the comet is about the only known variable unless it's a repeat offender. Brightness estimates for comets that we're observing for the first time are commonly out by a couple of orders of magnitude due to variations in outgassing, which is heavily influenced by composition and internal structure.

In this case we can't even make reasonable assumptions about a lot of those variables the way we might for a comet from our backyard. Hell, we don't even know what size it is. It might be a 10 km wide ball of loosely bound hydrogen ice that'll boil like all blazes or it might he a house-sized block of solid water ice that'll barely produce a coma and tail. Early results suggest that it's behaving a lot like a typical Oort Cloud object though.

Well let's hope for a spectacular display.  Um, when?
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#14

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Armageddon sick of these "visitors".
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#15

New Extrasolar Visitor
(09-15-2019, 10:45 PM)Gawdzilla Sama Wrote: Armageddon sick of these "visitors".

Good one!
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