APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

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Expand view Topic review: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Mon Dec 04, 2017 3:28 am

Garthok Gnarfle wrote:
Maybe instead of a vessel as in Rama it's a shard of diamond thrown off by a birthing star as in Odyssey.
https://en.wikipedia.org/wiki/Cave_of_the_Crystals#/media/File:Cristales_cueva_de_Naica.JPG wrote:

<<Cave of the Crystals or Giant Crystal Cave (Spanish: Cueva de los Cristales) is a cave connected to the Naica Mine at a depth of 300 metres, in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found. The cave's largest crystal found to date is 12 m in length, 4 m in diameter and 55 tons in weight. The cave is extremely hot, with air temperatures reaching up to 58 °C with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors. Without proper protection, people can only endure approximately ten minutes of exposure at a time.

The caves are accessible today because the mining company's pumping operations keep them clear of water. If the pumping were stopped, the caves would again be submerged in water. The crystals deteriorate in air, so the Naica Project is attempting to visually document the crystals before they deteriorate further. When mineral exploitation is ended in the area it is likely the pumps will be shut off and the cavern's water level allowed to rise again.>>

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Garthok Gnarfle » Mon Dec 04, 2017 1:32 am

neufer wrote: The rock interior could act as a safe time capsule for frozen Earth species specimens and various artifacts.

The rock should be covered with optical & radar corner reflectors so that it can be tracked from Earth for a long time as well as making it easily locatable for aliens.
Maybe instead of a vessel as in Rama it's a shard of diamond thrown off by a birthing star as in Odyssey.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by MarkBour » Fri Dec 01, 2017 1:23 am

I wonder what kind of magnetic moment Oumuamua has ...

(I recognized that shape immediately ... and it is well-named. Every righteous surfboard needs a good Hawai'ian name.)

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Mon Nov 27, 2017 9:28 pm

FOARP wrote:
InfinitiesLoop wrote:
Someone mentioned it in this thread already, but I think it deserves discussion -- what is the feasibility of a mission to outfit a visitor like this with sensors? Why build a probe when nature has provided one? We'd have to match its speed to be able to land on it, perhaps at that point you don't even need to land on it anymore. So I suppose the trick would be in getting something onto it without having to match its speed, like a snare or something. The more I think about it the more untenable it sounds, but there's gotta be something to it. Plenty of comets and asteroids with predictable orbits to practice on.
The problem here is: what exact problem are you solving by placing sensors on this rock (other than examining the rock itself, which is definitely worth doing)? To put anything on 'Oumuamua you need to match its velocity, so you're not solving a velocity problem. Getting anything there requires a space-craft capable of holding all the instrumentation so there's no structural issue you're solving. I suppose the rock could act as a dust-shield (so long as it's not tumbling too much) but that's about it. On the down-side it's not going anywhere we want to go (other than "To infinity! And beyond!") and so any instrumentation placed there will likely see a whole load of nothing outside of the rock itself that it wouldn't have seen otherwise going at the speed it would be going at.
The rock interior could act as a safe time capsule for frozen Earth species specimens and various artifacts.

The rock should be covered with optical & radar corner reflectors so that it can be tracked from Earth for a long time as well as making it easily locatable for aliens.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by FOARP » Mon Nov 27, 2017 10:24 am

InfinitiesLoop wrote:Someone mentioned it in this thread already, but I think it deserves discussion -- what is the feasibility of a mission to outfit a visitor like this with sensors? Why build a probe when nature has provided one?

We'd have to match its speed to be able to land on it, perhaps at that point you don't even need to land on it anymore. So I suppose the trick would be in getting something onto it without having to match its speed, like a snare or something. The more I think about it the more untenable it sounds, but there's gotta be something to it. Plenty of comets and asteroids with predictable orbits to practice on.
The problem here is: what exact problem are you solving by placing sensors on this rock (other than examining the rock itself, which is definitely worth doing)?

To put anything on 'Oumuamua you need to match its velocity, so you're not solving a velocity problem. Getting anything there requires a space-craft capable of holding all the instrumentation so there's no structural issue you're solving. I suppose the rock could act as a dust-shield (so long as it's not tumbling too much) but that's about it. On the down-side it's not going anywhere we want to go (other than "To infinity! And beyond!") and so any instrumentation placed there will likely see a whole load of nothing outside of the rock itself that it wouldn't have seen otherwise going at the speed it would be going at.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Fri Nov 24, 2017 12:35 am

Chris Peterson wrote:
rstevenson wrote:
Zoomer wrote:
" ...because it is the first asteroid ever detected from outside our Solar System -"
How is this possible unless Voyager1 somehow reported it?
Or is this just a simple and too common grammatical error? :|
It's not considered a grammatical error anymore. It is an all too common way of making what could have been an unambiguous statement into an ambiguous one. This casual way of speaking and writing is a plague, but it seems unstoppable. Most people just puzzle out the most likely meaning and move on.
It would never have been considered a grammatical error. And language is, by its nature, often ambiguous. But if anybody actually had to "puzzle out" the meaning here, they've got much deeper problems to deal with.
Click to play embedded YouTube video.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Chris Peterson » Thu Nov 23, 2017 6:22 pm

rstevenson wrote:
Zoomer wrote:" ...because it is the first asteroid ever detected from outside our Solar System -"
How is this possible unless Voyager1 somehow reported it?
Or is this just a simple and too common grammatical error? :|
It's not considered a grammatical error anymore. It is an all too common way of making what could have been an unambiguous statement into an ambiguous one. This casual way of speaking and writing is a plague, but it seems unstoppable. Most people just puzzle out the most likely meaning and move on.
It would never have been considered a grammatical error. And language is, by its nature, often ambiguous. But if anybody actually had to "puzzle out" the meaning here, they've got much deeper problems to deal with.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by rstevenson » Thu Nov 23, 2017 5:57 pm

Zoomer wrote:" ...because it is the first asteroid ever detected from outside our Solar System -"
How is this possible unless Voyager1 somehow reported it?
Or is this just a simple and too common grammatical error? :|
It's not considered a grammatical error anymore. It is an all too common way of making what could have been an unambiguous statement into an ambiguous one. This casual way of speaking and writing is a plague, but it seems unstoppable. Most people just puzzle out the most likely meaning and move on.

Rob

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Thu Nov 23, 2017 2:59 pm

Chris Peterson wrote:
Tszabeau wrote:
Surely, it is tumbling and not moving like a javelin through space, as depicted.
"Tumbling" means rotating around more than one axis. Some asteroids do tumble, but most do not. There's no particular reason we should expect this one to do so. And there is nothing in the image which suggests the direction of motion of the body. You are assuming it is "moving like a javelin", but it could be moving in any direction relative to its shape.
https://www.etymonline.com/word/tumble wrote:
tumble (v.) c. 1300, "to perform as an acrobat," also "to fall down," perhaps from a frequentative form of Old English tumbian "dance about, tumble, leap." This is of unknown origin but apparently related to Middle Low German tummelen "to turn, dance," Dutch tuimelen "to tumble," Old High German tumon, German taumeln "to turn, reel."
https://en.wikipedia.org/wiki/Herpolhode wrote:
Click to play embedded YouTube video.
<<A herpolhode is the curve traced out by the endpoint of the angular velocity vector ω of a rigid rotor, a rotating rigid body. The endpoint of the angular velocity moves in a plane in absolute space, called the invariable plane, that is orthogonal to the angular momentum vector L. The fact that the herpolhode is a curve in the invariable plane appears as part of Poinsot's construction.

The trajectory of the angular velocity around the angular momentum in the invariable plane is a circle in the case of a symmetric top, but in the general case wiggles inside an annulus, while still being concave towards the angular momentum.>>

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Chris Peterson » Thu Nov 23, 2017 2:40 pm

Tszabeau wrote:Surely, it is tumbling and not moving like a javelin through space, as depicted.
"Tumbling" means rotating around more than one axis. Some asteroids do tumble, but most do not. There's no particular reason we should expect this one to do so. And there is nothing in the image which suggests the direction of motion of the body. You are assuming it is "moving like a javelin", but it could be moving in any direction relative to its shape.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Tszabeau » Thu Nov 23, 2017 1:26 pm

Surely, it is tumbling and not moving like a javelin through space, as depicted.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Phantor48 » Thu Nov 23, 2017 6:51 am

Cue the music: Also Sprach Zarathustra!

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by BDanielMayfield » Wed Nov 22, 2017 9:51 pm

Wayne Jepson wrote:My understanding, from the various articles I've read about this object so far, is that the only arguments supporting this being a natural 'asteroid' are:

1) it's trajectory can be defined solely by it's initial velocity and direction of motion, as influenced by the gravity of our sun during its close pass
(i.e. there is no evidence that its path is influenced by any sort of active, on-board propulsion system; it is adrift / tumbling in space)
2) it is red; and,
3) of course its natural, there's no such thing as aliens.

On the other hand, arguments for it not being "natural" include:

1) we are tracking over half a million asteroids in our solar system, none of them are known to have an aspect ratio as great as 10:1.
2) a spacecraft that is no longer functional could easily have a similar observed trajectory, you can speculate on how and when it achieved its observed velocity; and,
3) it is red. Why not paint your spacecraft red?

Anyone else have any further insights to add to either side of the debate?
Good post Wayne. I agree that the redness adds nothing to the debate, as any object, natural or not, will accumulate reddish dust after millions of years in deep space. Might even be rust.

I know, it's a giant crystal of dilithium unobtainium oxide. :lol2:

Bruce

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Keyman » Wed Nov 22, 2017 8:18 pm

An extra special holiday bonus for me.
APOD and XKCD hitting on the same topic today.
https://xkcd.com/1919/

And their own follow on disussion:
http://forums.xkcd.com/viewtopic.php?f=7&t=123841

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by InfinitiesLoop » Wed Nov 22, 2017 7:55 pm

JohnD wrote:InfinitiesLoop
Just THINK for a moment.
This object was moving faster than anything else in the Solar System, 315,000 kilometres per hour.

67P/Churyumov–Gerasimenko's maximum velocity was 135,000 km/h, and the Rosetta mission was launched in 2004, to meet it in 2014, TEN YEARS LATER. It needed all that time for several 'sling-shots', three past the Earth and one past Mars to achieve rendezvous. There's a smashing animation of the process here: https://www.youtube.com/watch?v=ktrtvCvZb28

Now, how long have we known about Oumuamua? Since October 19th, this year. And it's moving more than twice as fast as 67P. Now, you answer your own question. Could we have set up a mission to catch, land on it and set up an obsevation post?
John
The first thing you need to do when solving a difficult problem is identify the things that make it difficult. No reason to stop there. I never claimed it would be easy -- in fact, suggesting one of the problems being matching its speed. Yes that is difficult, but not impossible. Knowing when one is coming is another problem, but early detection of things like this is bound to get better, hence my statement about having predictable objects to practice on. I think it'd be interesting to explore the possibilities, however difficult or crazy they may be.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Wayne Jepson » Wed Nov 22, 2017 7:34 pm

My understanding, from the various articles I've read about this object so far, is that the only arguments supporting this being a natural 'asteroid' are:

1) it's trajectory can be defined solely by it's initial velocity and direction of motion, as influenced by the gravity of our sun during its close pass
(i.e. there is no evidence that its path is influenced by any sort of active, on-board propulsion system; it is adrift / tumbling in space)
2) it is red; and,
3) of course its natural, there's no such thing as aliens.

On the other hand, arguments for it not being "natural" include:

1) we are tracking over half a million asteroids in our solar system, none of them are known to have an aspect ratio as great as 10:1.
2) a spacecraft that is no longer functional could easily have a similar observed trajectory, you can speculate on how and when it achieved its observed velocity; and,
3) it is red. Why not paint your spacecraft red?

Anyone else have any further insights to add to either side of the debate?

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by JohnD » Wed Nov 22, 2017 7:02 pm

InfinitiesLoop
Just THINK for a moment.
This object was moving faster than anything else in the Solar System, 315,000 kilometres per hour.

67P/Churyumov–Gerasimenko's maximum velocity was 135,000 km/h, and the Rosetta mission was launched in 2004, to meet it in 2014, TEN YEARS LATER. It needed all that time for several 'sling-shots', three past the Earth and one past Mars to achieve rendezvous. There's a smashing animation of the process here: https://www.youtube.com/watch?v=ktrtvCvZb28

Now, how long have we known about Oumuamua? Since October 19th, this year. And it's moving more than twice as fast as 67P. Now, you answer your own question. Could we have set up a mission to catch, land on it and set up an obsevation post?
John

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Wed Nov 22, 2017 6:51 pm

InfinitiesLoop wrote:
Someone mentioned it in this thread already, but I think it deserves discussion -- what is the feasibility of a mission to outfit a visitor like this with sensors? Why build a probe when nature has provided one? We'd have to match its speed to be able to land on it, perhaps at that point you don't even need to land on it anymore. So I suppose the trick would be in getting something onto it without having to match its speed, like a snare or something. The more I think about it the more untenable it sounds, but there's gotta be something to it. Plenty of comets and asteroids with predictable orbits to practice on.
http://en.wikipedia.org/wiki/Off_on_a_Comet wrote:
<<Off on a Comet (French: Hector Servadac) is an 1877 science fiction novel by Jules Verne. The story starts with a comet that touches the Earth in its flight and collects a few small chunks of it. Some forty people of various nations and ages are condemned to a two-year-long journey on the comet. They form a mini-society and cope with the hostile environment of the comet (mostly the cold). The size of the 'comet' is about 2300 kilometers in diameter - far larger than any comet or asteroid that actually exists.>>
----------------------------------------

The 36 inhabitants of Gallia include a German Jew, an Italian, three Frenchmen, eight Russians, 10 Spaniards, and 13 British soldiers. The main characters are:

* Captain Hector Servadac of the French Algerian army
* Laurent Ben Zoof, Servadac's aid
* Count Wassili Timascheff of Russia
* Lt. Procope, the commander of Timascheff's yacht, Dobrina
* Isaac Hakkabut, a German trader
* Nina
* Pablo
* Colonel Heneage Finch Murphy and Major Sir John Temple Oliphant of Britain's Gibraltar garrison.
* Palmyrin Rosette, the French discoverer of the comet and previously Servadac's teacher.
----------------------------------------
<<From the beginning Verne had problems with this novel. Originally he intended that Gallia would crash into the earth killing all on board. This may have been the motivation for his ghoulish and rather unfunny joke naming the hero "Servadac" with the mirror of the French word cadavres (="corpses"), predicting all would die on the "return". His publisher Hetzel would not accept this however, given the large juvenile readership in his monthly magazine, and Verne was forced to graft a rather unsatisfying ending onto the story, allowing the inhabitants of Gallia to escape the crash in a balloon.>>

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by InfinitiesLoop » Wed Nov 22, 2017 6:07 pm

Someone mentioned it in this thread already, but I think it deserves discussion -- what is the feasibility of a mission to outfit a visitor like this with sensors? Why build a probe when nature has provided one?

We'd have to match its speed to be able to land on it, perhaps at that point you don't even need to land on it anymore. So I suppose the trick would be in getting something onto it without having to match its speed, like a snare or something. The more I think about it the more untenable it sounds, but there's gotta be something to it. Plenty of comets and asteroids with predictable orbits to practice on.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Fred the Cat » Wed Nov 22, 2017 4:20 pm

Talk about a cat box survivor. :oops: It would be a giant “cat ass trophy” if the mess-enger "escaped" from a society of giant felines. :ohno:

Scoop up that asteroid. :wink:

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Spif » Wed Nov 22, 2017 4:17 pm

RocketRon wrote:
Spif wrote: If its incoming and outgoing trajectories seem to aim at the same star, that could be a somewhat convincing clincher.
incoming and outgoing trajectories are not consistent with this statement.

https://www.nasa.gov/sites/default/file ... k=178v74Z7
Local stars move relative to our own solar system. Those relative motions tend to be on the order of tens of km/s (except for halo stars, and "rogue" stars generally).

So that snapshot of the object's trajectory is not inconsistent with the speculative idea of a probe originating from and returning to the same star. (Although why someone would devise a mission for a probe to fly by and then return to the home system, I don't know. A more likely behavior would be to transmit findings back home and then move on to another nearby star. So if that outbound trajectory is aimed to intercept another star ... that would be a pretty impressive indicator of unnatural origin as well.)
RocketRon wrote:(If it was only sighted rather late, how was this path extrapolated ?)
Technically, it only takes three observed data points to determine the orbital trajectory of an object. You need four dimensions on those points: for example, two angles, range, and time. Generally you want to make the three measurements with a significant time separation to increase the accuracy of your projection. This is because time separation helps to decrease sensitivity to errors in your positional measures. Making more than three observations further increases accuracy of the projection. I'm guessing that we have hundreds of such data points.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Wed Nov 22, 2017 4:16 pm

Chris Peterson wrote:
RocketRon wrote:
Millions of years ??

With the distance it has to have come from - from even the closest possible star, and its (relatively) low speed,
it would more likely have been billions of years ago ?
It could be any long length of time. But millions of years is perfectly reasonable. We're talking about a body which is approximately co-orbiting with our own Solar System within the Milky Way. That means both us and it make a complete orbit around the center of our galaxy every 250 million years or so, passing or being passed by countless stars, rogue planets, rogue asteroids in similar orbits.
Hundreds of millions of years might be reasonable but billions of years is more reasonable.

(Just sagan...)

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Chris Peterson » Wed Nov 22, 2017 2:01 pm

RocketRon wrote:Millions of years ??

With the distance it has to have come from - from even the closest possible star, and its (relatively) low speed,
it would more likely have been billions of years ago ?
It could be any long length of time. But millions of years is perfectly reasonable. We're talking about a body which is approximately co-orbiting with our own Solar System within the Milky Way. That means both us and it make a complete orbit around the center of our galaxy every 250 million years or so, passing or being passed by countless stars, rogue planets, rogue asteroids in similar orbits.

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by Zoomer » Wed Nov 22, 2017 1:50 pm

" ...because it is the first asteroid ever detected from outside our Solar System -"
How is this possible unless Voyager1 somehow reported it?
Or is this just a simple and too common grammatical error? :|

Re: APOD: 'Oumuamua: Interstellar Asteroid (2017 Nov 22)

by neufer » Wed Nov 22, 2017 12:12 pm

Click to play embedded YouTube video.
Spif wrote:
Comes out of nowhere and pulls a nice tight slingshot maneuver well inside Mercury's orbit?

I'm starting to wish that maybe this thing just blew the Fermi Paradox away ;)

If its incoming and outgoing trajectories seem to aim at the same star, that could be a somewhat convincing clincher.

But then that speed of 26kps is just not practical for interstellar anything... 50k years just to cover the distance of Alpha Centauri.
Well...of course they came out of hyperspace in order to examine our solar system.

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