• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

'Oumuamua: Interstellar Object: Rendezvous With Rama?

Yithian

Yithian

Parish Watch
Staff member
Joined
Oct 29, 2002
Messages
36,431
Location
East of Suez
I've just read about A/2017 U1. Click-Bait title aside, it's an interesting phenomenon.

This mystery object may be our first visitor from another solar system ​
By Amanda Barnett, CNN
Updated 1618 GMT (0018 HKT) October 29, 2017​

comet20171025-16.gif


Astronomers around the world are trying to track down a small, fast-moving object that is zipping through our solar system.

Is a comet? An asteroid? NASA's not sure. The space agency doesn't even know where it came from, but it's not behaving like the local space rocks and that means it may not be from our solar system.
If that's confirmed, NASA says "it would be the first interstellar object to be observed and confirmed by astronomers."

"We have been waiting for this day for decades," Paul Chodas, manager of NASA's Center for Near-Earth Object Studies, said in a NASA news release. "It's long been theorized that such objects exist -- asteroids or comets moving around between the stars and occasionally passing through our solar system -- but this is the first such detection. So far, everything indicates this is likely an interstellar object, but more data would help to confirm it.

NASA says astronomers are pointing telescopes on the ground and in space at the object to get that data.
For now, the object is being called A/2017 U1. Experts think it's less than a quarter-mile (400 meters) in diameter and it's racing through space at 15.8 miles (25.5 kilometers) per second.

Continued Here:
http://edition.cnn.com/2017/10/27/us/mystery-object-solar-system-trnd/index.html
 
Interesting that it was briefly captured by Earth before flying out of the Solar System.
 
From this weeks Economist science section:-

The first visitor from another solar system has just been spotted

Rendezvous with Rama?

20171104_STC908.png

AEONS ago, perhaps long before Earth itself existed, a hunk of rock circling a star somewhere in the Milky Way was thrown out of its orbit so violently that it was ejected from its natal system. Thus began a journey that would, in time, take it within an astronomical hair’s breadth of humanity’s home planet. On October 19th this visitor was spotted by Rob Weryk of the University of Hawaii in pictures produced by Pan-STARRS 1, a telescope on Haleakala. It thus became the first interstellar interloper into
Earth’s solar system to be spied by astronomers.
Its origin is clear from its speed. When spotted, it was travelling at 25.5km per second. That is too fast for it to have a closed, elliptical orbit around the Sun. Nor could its velocity have been the result of an encounter with a planet giving it an extra gravitational kick, for it arrived from well above the ecliptic plane, close to which all the Sun’s planets orbit. Dr Weryk’s object, now named A/2017 U1 (the “A” stands for asteroid), thus almost certainly arrived from interstellar space.

Observations from other telescopes have confirmed A/2017 U1’s extrasolar origins. After swinging around the Sun, as the diagram shows, it passed about 25m km below Earth on October 14th, before speeding back above the ecliptic plane. It is now heading out of the solar system towards the constellation of Pegasus, at a speed of 44km per second.

Sci-fi buffs may find this tale familiar. One of the great works of 20th-century science fiction, “Rendezvous with Rama”, by Arthur C. Clarke, starts similarly. Rama, as the object in the novel is dubbed, turns out to be an uncrewed alien spacecraft, 54km long. It, too, arrives from the void, loops around the Sun, and vanishes into the distance again. Sadly, A/2017 U1 is no spacecraft. It is a rock about 400 metres across. But it still has an interesting story to tell.

Hello and goodbye

Models of planet formation suggest that interstellar objects such as A/2017 U1 are likely to be icy rocks known as comets, formed on the periphery of distant solar systems, rather than dry rocks, known as asteroids, dislodged from such systems’ interiors, which are places where any comet-like volatiles will have been driven off by the heat of their parent stars. Indeed, A/2017 U1 was first classified as a comet. But the absence of a tail of gas and dust, produced when comets fly close to the Sun, and analysis by Alan Fitzsimmons of Queen’s University in Belfast of sunlight reflected from its surface, suggest that surface is mostly rock.

One explanation is that over many millennia cosmic rays have transformed the icy, volatile chemicals that would be expected to stream off a comet into more stable compounds. Another is that the Sun is not the first star A/2017 U1 has chanced upon, and that the volatile materials have been boiled off by previous stellar encounters. Or it could be that the object actually was dry to begin with—perhaps once orbiting its parent star in an equivalent of the solar system’s asteroid belt and then having been ejected by an encounter with a Jupiter-like planet.

Another puzzle is why nothing like A/2017 U1 has been seen before. Theories of planet formation suggest such objects should be a reasonably common sight. Perhaps the theories are wrong. Or it could be that these interstellar visitors have been overlooked in the past, and that there will be a spate of such sightings in future.

The proof that interstellar wanderers like A/2017 U1 really do exist also touches on the question of how life got going on Earth in the first place. Though most researchers think it evolved in situ from non-living chemicals, a few favour the idea that this evolution happened elsewhere and that living things, in the form of bacteria, were carried to Earth fully formed, inside objects of this sort.

Whether life could survive such a journey is moot. Outer space has a temperature close to absolute zero, is full of harmful radiation and is moot.

Outer space has a temperature close to absolute zero, is full of harmful radiation and is of course a vacuum. But some forms of life are remarkably resilient, even to these sorts of extremity. Experiments that may shed some light on the matter are being planned as part of efforts to send unmanned, miniature space probes to stars close to the solar system.

As to the rock itself, it surely deserves a more memorable name than the one it sports at the moment. And a quick look at the list of existing asteroid names instantly suggests one. Perhaps in expectation of a discovery like this, the International Astronomical Union, which approves such names officially, has not yet called an asteroid “Rama”. How about it, chaps?

Source (Maybe behind a paywall) : https://www.economist.com/news/scie...st-visitor-another-solar-system-has-just-been
 
This has been mentioned on the Astronomy Thread in New Science, but I like the Arthur C. Clarke spin it has been given here.
 
Or we could be too busy looking at Rama to notice the death inducing lump of rock hurtling our way...
 
Dinobot said:
How long until some Nibiru/Doomsday weirdo says it will crash into Earth and kill us all? ...
Click to expand...

On a somewhat more realistic note ...

The Nibiru crowd was recently in the spotlight - first for the usual dire predictions, then for back-pedaling / revisionism when nothing happened on the appointed date.

I would have thought at least some of the Planet X believers would have seized on A/2017 U1 as an excuse for mitigating this most recent embarrassment. For example:

- "We were generally right about something incoming, but simply mistook it for the Big One."
- "We were right about the approaching threat, but didn't foresee it missing us."

Has anyone seen any evidence of the Nibiru / Planet X crowd citing, much less leveraging, the A/2017 U1 story?
 
Dinobot said:
How long until some Nibiru/Doomsday weirdo says it will crash into Earth and kill us all? Hope you all have your Bakker Buckets Of Food ready!
Click to expand...

May I take a bargain bucket?
 
Bizarre shape of interstellar asteroid
By Paul RinconScience editor, BBC News website
  • 20 November 2017
_98827075_mediaitem98827074.jpg
Image copyrightESO/M. KORNMESSER
Image captionArtwork: 'Oumuamua is now fading from the view of telescopes
An asteroid that visited us from interstellar space is one of the most elongated cosmic objects known to science, a study has shown.

Discovered on 19 October, the object's speed and trajectory strongly suggested it originated in a planetary system around another star.

Astronomers have been scrambling to observe the unique space rock, known as 'Oumuamua, before it fades from view.

Their results so far suggest it is at least 10 times longer than it is wide.

That ratio is more extreme than that of any asteroid or comet ever observed in our Solar System.

etc...
Click to expand...

http://www.bbc.co.uk/news/science-environment-42053634
 
Yeah, that was weird.
Probably the molten ejecta from some massive explosion, shaped that way because of the immense speed (and subsequent freezing as it travelled through space).

Or an alien spacecraft.
 
The interstellar asteroid seems even stranger than anyone could have expected
http://www.eso.org/public/usa/news/eso1737/
This unusually large variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape. We also found that it has a dark red colour, similar to objects in the outer Solar System, and confirmed that it is completely inert, without the faintest hint of dust around it.
Click to expand...
This could be an ancient spacecraft on an aeons-long journey to ... somewhere. The shape is completely different to anything I would expect to form naturally.
 
eburacum said:
... The shape is completely different to anything I would expect to form naturally. ...
Click to expand...

Let's not assume the artist's conception reflects known facts.

We don't know anything about Oumuamua's shape except for its relative (overall) dimensions. Estimates of its length / width ratio vary from the popularly-cited 10:1 to a range of 5:1 to 6:1 (cited in the hardcore scientific articles). Even these points are based on a number of assumptions which render them somewhat speculative.
 
The light curve might conceivably be due to a wild variation in albedo, although this is unlikely given the length of time it has (probably) been travelling in interstellar space. Even 5:1 would be a highly unusual shape.
One asteroid with a most curious shape is 216 Kleopatra, which is shaped like a bone and is about 5:1 in ratio. This seems to be an entirely natural object, and may be two objects loosely in contact with a central dust sheath.

kleo_arecibo.gif

If interstellar asteroids are anything like this, they would be intriguing objects to study in detail.
 
Anther odd thing about this object is that it did not form a coma. If it were made of ice, then it should have out-gassed, giving a visible cometary cloud as it approached the Sun. But it didn't, suggesting that it was made of metals. Unusual for a chunk of metal to be flung out of a system, since objects near the edge of a solar system are usually made of ice.
 
eburacum said:
The interstellar asteroid seems even stranger than anyone could have expected
http://www.eso.org/public/usa/news/eso1737/

This could be an ancient spacecraft on an aeons-long journey to ... somewhere. The shape is completely different to anything I would expect to form naturally.
Click to expand...
Expect the unexpected. There must be shapes ahoy in every possible variation the imagination could and couldn't anticipate. Our imagination thus far has been molded by the spheres, eliptics and barbels of our local solar experience. Gravity favours routine, as per our environment, but there must be stuff warped by forces and randoms beyond anything we can conceive of out there in the distant reaches. My beard of a morning is a case in point.
 
I couldn't find a thread this would fit in - though if there is one, merge away mods!

An asteroid-like object from elsewhere in the galaxy, called Oumuamua, paid a visit to Earth’s Solar System in mid-October; since then, scientists haven’t been able to shake it off as just another asteroid. Understandably so, given that it was the first object of its kind ever observed. Its unique status drove researchers at Breakthrough Listen, a privately-funded effort to search for extraterrestrial intelligence, to keep a close eye on it. Their goal? To see if the bizarre, unique properties of Oumuamua hint at any "artificial" origins — that is, a whiff of extraterrestrial design.

Oumuamua, which is Hawaiian for "an object from afar," was first observed by a postdoctoral researcher at the University of Hawaii who was sifting through the data stream from the Pan STARRS astronomical survey of the sky. The researcher noticed the object was highly elongated, like a stick, with a long axis 10 times longer than its short axis. Researchers have long suggested this could be an ideal shape for an interstellar spacecraft, as it would minimize abrasions from interstellar gas and dust.

Now, scientists at Breakthrough Listen, a global astronomical program searching for evidence of civilizations beyond Earth, are gearing up to use the Robert C. Byrd Green Bank Telescope in Green Bank, West Virginia, on December 13 to see if they can hear any radio signals being emitted by the object. If they do, it may be strong scientific evidence of alien life.
Click to expand...

Source: https://www.salon.com/2017/12/11/researchers-to-test-interstellar-asteroid-for-alien-influence/

Thing is though, what if they use something else than radio signals? How about subspace communications?
 
A very entertaining discussion at Centauri Dreams about this object here.
https://www.centauri-dreams.org/?p=38844
Two interesting points; James Benford (who is the brother of the Sci-Fi author Gregory Benford; both are physicists) points out that the object is roughly the same shape and size as the Shard, and also roughly the same shape and size as many recent concepts for interstellar spacecraft.

Secondly the object is tumbling in an uncontrolled fashion every seven hours or so - this is not optimal behaviour for any kind of interstellar craft. There's no point building a streamlined spacecraft to reduce the cross-sectional area in flight then set it tumbling at random. You couldn't even generate artificial gravity using this sort of Non-Principal Axis rotation; people would just be falling all over the place.
 
eburacum said:
There's no point building a streamlined spacecraft to reduce the cross-sectional area in flight then set it tumbling at random. You couldn't even generate artificial gravity using this sort of Non-Principal Axis rotation; people would just be falling all over the place.
Click to expand...

I don't think the suggestion is that there are aliens in there, merely that this could be a probe. The tumbling might be unintentional.

Personally, I just think it's a waste of money.
 
eburacum said:
There's no point building a streamlined spacecraft to reduce the cross-sectional area in flight then set it tumbling at random. You couldn't even generate artificial gravity using this sort of Non-Principal Axis rotation; people would just be falling all over the place.
Click to expand...
I take the point, but what grounds are there for asserting that the tumbling was induced deliberately? Presumably at least some of the hypothetical civilisations which are sufficiently advanced to create a large space-going vessel are not necessarily also sufficiently advanced to be able to predict and prevent all possible calamities. In other words, if it is a spacecraft, perhaps it's blown a tyre.
 
You must log in or register to reply here.
Back
Top