'Oumuamua is not an alien spacecraft: study

'Oumuamua is not an alien spacecraft
In this artist's concept, the interstellar object 'Oumuamua is depicted as a cigar-shaped body. A new analysis strongly suggests that 'Oumuamua has a natural origin and is not an alien spacecraft. Credit: ESO/M. Kornmesser

On October 19, 2017, astronomers discovered the first known interstellar object to visit our solar system. First spotted by the Panoramic Survey Telescope and Rapid Response System 1 (PanSTARRS1) telescope located at the University of Hawaii's Haleakala Observatory, the object defied easy description, simultaneously displaying characteristics of both a comet and an asteroid.

Astronomers formally named the object 1I/2017 U1 and appended the common name 'Oumuamua, which roughly translates to "scout" in Hawaiian. Researchers from around the world raced to collect as much data as possible before 'Oumuamua traveled beyond the reach of Earth's telescopes. In all, they had only a few weeks to observe the strange visitor.

Early reports of 'Oumuamua's odd characteristics led some to speculate that the object could be an alien spacecraft, sent from a distant civilization to examine our star system. But a new analysis co-led by Matthew Knight, an associate research scientist in the University of Maryland Department of Astronomy, strongly suggests that 'Oumuamua has a purely natural origin. The research team reported their findings in the July 1, 2019, issue of the journal Nature Astronomy.

"We have never seen anything like 'Oumuamua in our solar system. It's really a mystery still," Knight said. "But our preference is to stick with analogs we know, unless or until we find something unique. The alien spacecraft hypothesis is a fun idea, but our analysis suggests there is a whole host of natural phenomena that could explain it."

As Knight and his colleagues summarized in their study, 'Oumuamua is red in color, similar to many small objects observed in our solar system. But that's where the familiarity ends.

'Oumuamua likely has an elongated, cigarlike shape and an odd spin pattern—much like a soda bottle laying on the ground, spinning on its side. According to Knight, its motion through our solar system is particularly puzzling. While it appeared to accelerate along its trajectory—a typical feature of comets—astronomers could find no evidence of the gaseous emissions that typically create this acceleration.

"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid," Knight said. "But visually, it hasn't ever displayed any of the cometlike characteristics we'd expect. There is no discernable coma—the cloud of ice, dust and gas that surrounds active comets—nor a dust tail or gas jets."

International team of comet and asteroid experts agrees on natural origin for Oumuamua
This artist's impression shows the first interstellar object discovered in the Solar System, Oumuamua. Observations made with the NASA/ESA Hubble Space Telescope, CFHT, and others, show that the object is moving faster than predicted while leaving the Solar System.The inset shows a color composite produced by combining 192 images obtained through three visible and two near-infrared filters totaling 1.6 hours of integration on October 27, 2017, at the Gemini South telescope. Credit: ESA/Hubble, NASA, ESO/M. Kornmesser, Gemini Observatory/AURA/NSF

Knight worked with Alan Fitzsimmons, an astronomer at Queen's University Belfast in Northern Ireland, to assemble a team of 14 astronomers hailing from the U.S. and Europe. The International Space Science Institute in Bern, Switzerland, served as a virtual home base for the collaboration.

"We put together a strong team of experts in various different areas of work on 'Oumuamua. This cross-pollination led to the first comprehensive analysis and the best big-picture summary to date of what we know about the object," Knight explained. "We tend to assume that the physical processes we observe here, close to home, are universal. And we haven't yet seen anything like 'Oumuamua in our solar system. This thing is weird and admittedly hard to explain, but that doesn't exclude other natural phenomena that could explain it."

The new research paper is primarily an analysis of existing data, including a December 2017 study of 'Oumuamua's shape and spin pattern co-authored by Knight and a team of UMD astronomers. This paper, published in The Astrophysical Journal Letters, relied on data from the Discovery Channel Telescope (DCT) at the Lowell Observatory in Arizona. UMD is a scientific partner of the DCT, along with Boston University, the University of Toledo and Northern Arizona University.

Knight, Fitzsimmons and their colleagues considered a number of mechanisms by which 'Oumuamua could have escaped from its home system. For example, the object could have been ejected by a gas giant planet orbiting another star. According to theory, Jupiter may have created the Oort cloud—a massive shell of small objects at the outer edge of our solar system—in this way. Some of those objects may have slipped past the influence of the sun's gravity to become interstellar travelers themselves.

The research team suspects that 'Oumuamua could be the first of many interstellar visitors. Knight is looking forward to data from the Large Synoptic Survey Telescope (LSST), which is scheduled to be operational in 2022.

"In the next 10 years, we expect to begin seeing more objects like 'Oumuamua. The LSST will be leaps and bounds beyond any other survey we have in terms of capability to find small interstellar visitors," Knight said. "We may start seeing a new every year. That's when we'll start to know whether 'Oumuamua is weird, or common. If we find 10-20 of these things and 'Oumuamua still looks unusual, we'll have to reexamine our explanations."


Explore further

The three surprises of 'Oumuamua

More information: The natural history of 'Oumuamua, Nature Astronomy (2019). DOI: 10.1038/s41550-019-0816-x , https://nature.com/articles/s41550-019-0816-x
Citation: 'Oumuamua is not an alien spacecraft: study (2019, July 1) retrieved 17 August 2019 from https://phys.org/news/2019-07-oumuamua-alien-spacecraft.html
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Jul 01, 2019
I'm not one to jump on the "It's Aliens" bandwagon but seriously this article sucks.

If there are a host of natural explanations, why are none spelled out?

How can it accelerate with no propulsion (no comet like outgassing) via paths not dictated by gravity?

If you can't answer that via a natural explanation, then you have no natural explanations.

Jul 01, 2019
Magnetism? Fields propagated by its shape, rotation?

The alien explanation is the non-interrogative view. That doesn't mean it couldn't be aliens though.

Jul 01, 2019
"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid,"


I take that to mean O. was traveling faster than solar system escape velocity and therefore took a hyperbolic path according to the laws of physics. Now if there was an anomalous acceleration or course change away from that hyperbolic path, that needs to be QUANTIFIED. Are we taking about a tiny bit of undetected outgassing causing a barely detectable trajectory change or making a 90 degree turn on a proverbial dime? My guess is that O. is a weird rock, not an alien spacecraft. If you want to show O. is an alien spacecraft then you need to try to explain why it took the path it did. On the other hand, maybe we should go after it to be certain.

https://en.wikipe...ajectory

Jul 01, 2019
The point being, they say it didn't follow a parabolic trajectory given by just gravity, and it didn't have any detectable outgassing that would be expected in order to explain it's trajectory using the only other examples we have (comets)... So provide a natural explanation that fits the data if there are a host of them.

I'm not trying to argue that there are none. Just that the entire point of the article was to say that the thing was a rock and our studies show this to be the most likely explanation but gives absolutely zero examples of why they came to that conclusion. Only specific reasons why they can't say it was natural given common phenomena like asteroids / comets. Either the way the post was written is garbage or the study is borderline useless.

Jul 01, 2019
"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid,"


I take that to mean O. was traveling faster than solar system escape velocity and therefore took a hyperbolic path according to the laws of physics.


Traveling faster than the escape velocity doesn't preclude it from being affected by gravity, which is what is being called out.

It apparently did not follow the path simulated if it were not being affected by anything other than gravity (which is what we would expect from an inert rock). So what gave it a different trajectory? Some unaccounted for acceleration force is at play and that is what the study should have been calling out potential explanations of in this article.

Jul 01, 2019
The title of the article doesnt match the actual text inside of it. There is no ruling out of alien spacecraft inside.

Jul 01, 2019
I attempt to explain the odd acceleration of Oumuamua by positing a modified gravity theory; this theory would also explain the phenomena that current theory attempts to explain with "dark matter" and "dark energy".

ABSTRACT

Galactic rotation rates, the distribution of matter in the early universe shown by the scale of anisotropies in the CMB, and cosmological expansion present problems that current theory attempts to resolve by positing dark matter and dark energy. This paper posits that gravitational force is a dampened wave function dependent upon mass and distance. Therefore gravity reverses at regular dampened intervals. This reversal would also be in effect at smaller scales such as our own solar system, implying that current theory may have overlooked evidence of this in the data from various probes that have been launched.

LINK: https://redd.it/ao8vfo

Jul 01, 2019
as soon as i saw the clickbait headline (res, yes,i admit, more sensible than most)
i knew it would rile up the comicbook inspired into commenting.
i guess, whatever it takes to inveigle the uneducated to attempt to read a real science article.

questions to be answered:
"but seriously this article sucks."
ans: because the article is providing youwith facts
you do not want to read!

?Q: If there are a host of natural explanations, why are none abs: spelled out?"
ans: the authors assumed you know basic 18th century physics as developed by Isaac Newton & Émilie du Châtelet

?Q: How can it accelerate
ans: pick up a "massive" rock
hold it over your feet
let go...

?Q: with no propulsion (no comet like outgassing)
ans: correct. Oumuamua is an asteroid, not a comet

"YOU""have no natural explanations?"
for more facts you will ill refuse to read: The natural history of 'Oumuamua, Nature Astronomy (2019). DOI: 10.1038/s41550-019-0816-x


Jul 01, 2019
as soon as i saw the clickbait headline (res, yes,i admit, more sensible than most)
i knew it would rile up the comicbook inspired into commenting.
i guess, whatever it takes to inveigle the uneducated to attempt to read a real science article.

questions to be answered:
"but seriously this article sucks."
ans: because the article is providing youwith facts
you do not want to read!


Are you joking / high or just stupid?

The article refutes your comment that you are implying reflects the article.

According to Knight,.... While it appeared to accelerate along its trajectory—a typical feature of comets—astronomers could find no evidence of the gaseous emissions that typically create this acceleration.


"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid," Knight said.

Jul 01, 2019
So the article itself is saying it didn't behave like any known asteroid where it's trajectory is decided by gravity and it accelerated like we have observed comets to accelerate but without any other evidence of any comet-like attributes. Yet it states that the study concludes it's got a whole lot of natural explanations for the observations, yet the article provides none. Just statements about how weird it was and how we have no other examples of something behaving similar.

I'm pretty confident by comment is spot on ..this article sucks or the study does. If you're going to say we have concluded a number of natural explanations, then you should at least spell out the best or best few. This article contains no information about what it's thesis is about.

Jul 01, 2019
I'm not one to jump on the "It's Aliens" bandwagon but ...

If there are a host of natural explanations, why are none spelled out?
Do you always says and/or assume if we currently don't know a natural explanation for something then its probably caused by alians? If we don't currently have a natural explination for something, why assume its probably alians? Many things once had no natural explination that were later shown to have a natural explination; Examples include what causes rainbows or lighning and why didn't anyone assume alians caused that? In contrast, there is yet to be a single example of something that once had no natural explination that later was shown to have one involving alians! That past hystory should tell you that one's defualt assumption should always be, until if or when we have some pretty good reason to think otherwise, if we currently don't know a natural explanation for something then its almost certainly not caused by alians!

Jul 01, 2019
This article doth protest too much!

Why is oumuamua like an alien? What needs to be adequately explained?

1) it did a perfect 60 degree NASA style gravity assist relative to the sun's direction of motion, and swung by the most interesting blue planet just as that blue planet was orbiting round that side of the sun.

2) it's velocity was changing as it was leaving yet there was not comet like offgassing visible. This type of velocity change from a spinning oblong or dumbbell shaped object is consistent with a gravity assist engine.

See: "Gravity Assist Engine for Space propulsion" by Arne Bergstrom

https://www.scien...14000745

So the real question is this: Where is it headed, and is it lining up for another near 60 degree NASA style gravity assist with another star?

Everything else is chicken sh*t.


Jul 01, 2019
No evidence means
NO EVIDENCE!

"via paths not dictated by gravity?" you base this on what professionally gathered database?

ask yourself, the internet nutcase insisting he can set O's course without any possibility of error?
would you let him pilot your family aircraft?

you need to learn the difference between momentum & acceleration & how delta-v works & ballistic

using a minimal guesstimate
a mass of 100,000 kilotons, what is the physical amount of reaction mass it would take to accelerate from 24 k/s to over 80 k/s?
Then decelerate that mass back down to 24+ k/s?

how bright would the plume of exhaust be as it passed the Earth's orbit?
in either direction?

as us normal with asteroids skimming the Sun, there was no infrared detected of 'Oumuamua.

which would mean the "Big O" had a magical propulsion system without any heat or other radiation to detect?

now you've made the wild claims, unsupported by the observed evidence.
now you need to produce verifiable evidence.

Jul 01, 2019
Read the article. There would be no plumes or even detectable heat in a spinning gravity assist tidal engine. And no one saw it before apogee.



1) it did a perfect 60 degree NASA style gravity assist relative to the sun's direction of motion, and swung by the most interesting blue planet just as that blue planet was orbiting round that side of the sun.

2) it's velocity was changing as it was leaving yet there was not comet like offgassing visible. This type of velocity change from a spinning oblong or dumbbell shaped object is consistent with a gravity assist engine.

See: "Gravity Assist Engine for Space propulsion" by Arne Bergstrom

https://www.scien...14000745

So the real question is this: Where is it headed, and is it lining up for another near 60 degree NASA style gravity assist with another star?

Everything else is chicken sh*t.


Jul 01, 2019
The article is worth than meaningless. It smacks of scientific whitewash in its tone and cursory treatment of any facts whatsoever. And, begs the question: which country is secretly planning a rocket to try to catch up to it?

Jul 01, 2019
Pretty sure rjwillsj is either responding to a different article or not reading this one at all.

I'm not making any assumptions. I'm just copy and pasting quotes directly from the article posted here.
You can't have the article state multiple aspects of the observation don't fit how we know asteroids move then say we should just assume it is an asteroid without any reason. The reason is what the study was supposed to be giving us here and it did not.

Stop being a raging keyboard jockey for a second and read the article. It is devoid of anything backing it's thesis.

Jul 01, 2019
it's not about what I think it is, or what anyone here thinks it is. It's about an article who's purpose was to explain what this study found to be the most likely natural explanations of what caused the anomalies in the observations but did not. The article is the entity that is assuming there is a contrary opinion to a natural phenomena (it spends a good deal of time going over that). Not me.

If you're upset about someone talking about aliens or making theories about things that are easily explainable without introducing aliens / god / magic then be upset with this article. It did nothing to explain why it's not, only made various statements that actually undermine it's supposed point.

It's like an entire paragraph that actually talked about the study's findings was left out. Hence why I stated that this article was garbage.

Jul 01, 2019
Darth,

Any reply you make to him is purely for the benefit of less informed readers of the comment section. He either doesn't understand or is deliberately trolling to backstop the conventional wisdom regardless of the contents of any particular article.

Jul 01, 2019
This Alien Space Craft

Oumuamua took 20,000years to come close to our sun
Then it's taking 20,000years to leave our sun
Where
It is taking millions of years to pass all the suns on its endless journey

For if we want to believe
Oumuamua is an alien space craft
For one it did not make a refuelling pit stop
It did not even stop to say hello

For
What are these chances?
After stumbling over planet earth
That in these millions of years
Oumuamua is travelling
Of stumbling over a planet
In this infinite vacuum containing living breathing talking life
You can be certain as this vacuum is infinite
Oumuamua has never come across life before and will never come across life ever again

This proves this point
Oumuamua is not a space craft
Oumuamua does not contain aliens
For they would have stopped for a chat
And a pint down at the pub
Dined out in the prestigious restaurants round the world
For if you were living in this rock for millions of years
You'd be out like a shot without hesitation!

Jul 01, 2019
ahh but jax,
there will be expensive pieces of taxpayer property flying all over the place as the satellite's torque rips it apart.

calling that pretentious excuse for an over-priced centrifuge
a "Tidal-Engine"?
would be as if you swirled a cup of kool-aid in your hand
& then claimed it was exactly
similar to an ocean tide.

do any of you understand that a "Tidal Engine" would not propel a space ship anywhere you'd want to go?

see "vomit comet"

hell, none of the comicbook space drives will even get you off the ground. before the strings to the supporting balloons break!

as for "Big O" being an interstellar probe
it missed!
we missed our cue to
"drop'em & grab your ankles!"

too many people have accepted wild, student bong-fest brain-storming speculations as holey scripture handed down, inscribed on stone tablets.

as any honest author would warn you?
"A "good" story is not necessarily a "true" story!"

Jul 01, 2019
If O. is a alien spacecraft, I can say I am relieved they threw a probe at us that uses a big spring for added propulsion (Darth's link, Figure 2). It sounds like we are being invaded by Wile E. Coyote. :-)

https://www.scien...14000745

I studied this situation very carefully on Saturday mornings when I was 8 years old. All we have to do to fend off an invasion is position a big painting of an enticing-looking planet in front of a black hole and the entire Coyote invasion force will end up in the black hole. :-)

Jul 01, 2019
for those of you whining that
"I am not responding to the article posted"?
you need to re-read my original comments.
where i told you to look up the original published papers from which this article was "interpreted".

however, the impression i'm getting from the scarcity of informed responses is?
that you have no experience working in science or technology.
upon which empirical research is based.

i would suggedt you need to start with basic pilot training.
hardwork will help you gain a basic background in how machines actually work.

or at least a general mechanics course at your local junior college.

video-games ain't training.

the v-g ads promised you a "learning experience"?
i'd say they taking your money was not educational enough?

if a shoe salesman handed you a pair of mukluks.
promising you these are magical shoes
that will make you as graceful as a prima dona on the ballet stage?

& you willingly gave him payment?

frankly & ernestly?
you are pretty hopeless!

Jul 01, 2019
The sole purpose of this article was to get this headline on CNN. "This interstellar visitor was not an alien spacecraft, researchers say"
Mission accomplished, 99% of people never read the article and said, oh, ok, moving on.


Jul 01, 2019
I will answer my own query. As I wrote above, "Now if there was an anomalous acceleration or course change away from that hyperbolic path, that needs to be QUANTIFIED."

It looks like the anomalous acceleration was AFTER heating from the sun and ONLY amounted to one thousandth of the expected velocity. This is completely consistent with outgassing, whether it was detected or not. Don't forget this is a small object a huge distance away.

https://www.salon...partner/

Jul 01, 2019
uh oh!
i_i just_just fell_fell into_into Mark's_Mark's coyote_coyote trapping_trapping
Black_Black Hole_Hole!
ECHO _ Echo _ echo

how appropriate!
the Coyote Trickster Goddess is my deity of choice.

good old free will...

Jul 01, 2019
Darth,

Any reply you make to him is purely for the benefit of less informed readers of the comment section. He either doesn't understand or is deliberately trolling to backstop the conventional wisdom regardless of the contents of any particular article.


Trolling indeed. Not sure which I prefer more.... people on here that try and push pseudoscience or the people so hung up on their own internal debate that they're blind to what's actually being discussed and just vomit that internal dialogue into any related topic.

Pretty sure everyone else got the fact that this article was garbage.

Jul 01, 2019
Gravitational Propulsion on these Infinite Vacuous Seas

Rrwillsj
do any of you understand that a "Tidal Engine" would not propel a space ship anywhere you'd want to go

Are, rrwillsj
A rarity indeed
Even rarity of rarity in rrwillsj style
For even, rrwillsj
Just the mere mention, rrwillsj, of Propulsion
Makes this phys.org quake
For shiver my timbers, rrwillsj
A ship sailing these vacuous seas
Requires propulsion
For it matters, not how tenuous this link with reality, rrwillsj
For it is to be discussing tidal, gravitational
For this is discussing this rarity, Propulsion
Foreth we willeth nevereth travel these vacuous seas without Propulsion
Oumuamua has a gravitational Propulsion engine
That is orbitaly tidally sailing this vacuous sea on the whims of gravity

Gravity, a Propulsion Engine Propelling at this Velocity of Light

Jul 01, 2019
Darth, I get your point, there is not a lot of meat in the article above that could have been titled, "Smart Folks Conclude O is Not Alien." I think rrwillsj went to town on you because he hates when people come to unsupported, unscientific conclusions based on "wild, student bong-fest brain-storming speculations." You can probably tell that nobody here is treating this too seriously and I thought my coyote analogy was at least a little humorous.

O is simply moving too slow for any kind of reasonable interplanetary probe, tumbling nearly chaotically and a comet-like 1/1000 change in velocity after being cooked by the sun at ~0.25 au are not the kind of facts that would lead one to conclude it must be alien technology. It is a funky rock and worth a look on that basis, but that's it. Now don't get me wrong. I estimate there is at least one alien civilization superior to ours in at least one way between 4 light years and 4 billion light years away.

Jul 01, 2019
Mark you are still left with the problem of no heat detected.

if, it could be proven that Oumuamua was possibly the remanent core of an ancient comet?
it would be more believable that over millions, maybe billions of years?
the cometary volatiles would be long-past their sell-by date. sublimating, siphoning-off, vanishing long ago.

consider how close Oumuamua approach to our Sun.
as it reached speeds in excess of 80 km/s?
it did not break up as it was whipped around & flung away.

if there had been any volatiles?
why didn't the Corona boil those off?
which would have blasted off the surface crust & left a residual heat signature.

yet, as usual with observed sun-skimming asteroids, Oumuamua was undetectable by infra-red devices.

afterwards.

a close fly-by to a star, leaves comets warmer than metallic rocks.
the only logical conclusion left without new evidence?
is that "Bif O" is a solid shard of metallic core similar to what you would get by smashing up Ceres.

Jul 01, 2019
I came to no conclusion except that this article came to none, and especially not the conclusion the title made and failed to disprove it's own contrarian points.

If you are going to have an article to make a point against an idea that the article itself makes but you end up never making that point, you fail at every level of a scientific argument and at anything remotely looking like decent writing. It isn't the readers job to do your work for you if you decide to make a point.

We can't even talk about the basic outcome of this study without reading about it elsewhere because it isn't even summarized in the article. So it serves no purpose.

Rrwillsj decided to have an argument about something he already wanted to argue about. Which is fine. Trollish but whatever... Not a valid response to what I said though and hardly an effective war on misinformation when it completely misses the point. Ironic

Jul 01, 2019
Our first every close up view of dark matter, it would have grown the hydrogen/proton shell a long time ago.

Probably fizzed from it's original core, and popped up to our weight space, likely still bound to it's underlying dark matter core of origin hence the irregular course.

Jul 01, 2019
Lies, BIG LIES, and Propaganda, that is that this above main article is. It is meant as a disinformation piece, part of a larger campaign to quash the truth. We know of at least 50+ or more space faring alien spiecies, and have dealings with many of them secretly among several or our 'leading space interested' nations. Whether this 'local' society of species wants the likes o' us among them is another question that has not been answered as yet.

Our neighbors have been watchin' us for quite some time, and i have a feeling that we act a wee' bit juvenile for their liking. We are at least the second incarnation of 'advanced' peoples bioengineered from local 'lower' species from this world. Possibly our difference is that we have soul carriers...with souls. That may be our salvation.... the universal God has taken what is good and written it on our hearts... (New American Bible) translation: a moral code has been written into our mitochondrial DNA and our souls can see.

Jul 02, 2019
Their cloaking device seems to have worked even better than expected...

Jul 02, 2019
I'm backing up Darth Ender - There is no scientific principle saying everything we observe is natural. Never before seen characteristics and orbit maneuvers are what we expect to see supposing Oumuamua is an alien artifact. That's not saying it's aliens, but until the puzzling characteristics (especially its dimensions, orbit and surface properties) are explained, alien technology is a contender. What is the cognitive bias against this? I think people reacting so stridently fear being in the lunatic camp and it clouds their objectivity.

I agree also that the article is dishonest and badly written. Nothing in the text supports the proposition that "it is not aliens."

Jul 02, 2019
I still think the artist's rendering makes it look like a drifting, rock encrusted General Products Hull.
(Larry Niven's Known Space series.)

Jul 02, 2019
"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid,"

So gravitational theory failed, whooptie doo, gravitational theory fails all the time. What this does show, is how entrenched belief can cause folks to have irrational reactions. If gravity doesn't work, it must be aliens. It's just like the religionists blaming unknowns on god. It's quite amusing, there are natural possibilities but belief blinds the acolytes.

Jul 02, 2019
oh deer, you still /cant" get it.

a clickbait headline over an article interpreted by an non-science major student in a work/study program.
& edited by someone who had taken a science course in the 80's
based on the instructor's required text published in the 70's.

but then going to the original research papers & actually reading those sources?
would be too much effort to ever expect of you...

Jul 02, 2019
I'm not one to jump on the "It's Aliens" bandwagon but seriously this article sucks.
If there are a host of natural explanations, why are none spelled out?


Seriously!? You are complaining about the article, never considering the science behind?

I am not going to bother looking into the paper for you, you need to do that for yourself, but from teh abstract:

"Here we review our knowledge and find that in all cases, the observations are consistent with a purely natural origin for 'Oumuamua."

t's about an article who's purpose was to explain what this study found to be the most likely natural explanations of what caused the anomalies in the observations but did not.


No, it is decidedly not. It is a (click-bait, by market intention) press release that is intended to inform scientists and the paying public that there is an interesting paper that they may want to look into.

- tbctd-

Jul 02, 2019
- ctd-

Sure, other scientists and the public wantt to have summaries - but that is what the abstract is for - and ELIF - but that is not yet encouraged much (some journals have started with "ELI graduate" summaries).

If you want to read about science on a science site, you need to take time to learn how both how these things work, and learning about the science market ecosystem helps too as in all other social areas. Think of it as good for your blood pressure. :-)

Jul 02, 2019
On the larger issue, all the odd properties of 'Oumuamua, as well as the expected, has been answered in various ways by noting already observed - albeit admittedly rare - objects that correspond. The aspect ratio was not well measured and could be explained by either being within the usual distribution or by an ice covered object that was smaller than naive estimates would predict. The rotation could be explained by the same high albedo or by having the object dispersed by the Sun (which has happened with comets at least once). The acceleration could be explained by unseen jets (has happened before) or by a dispersed object behavior.

And lastly, the obsession with unusual objects and pattern search for 'others' are well within what we are used to see too. None of this is conclusive evidence, but we know that there is nothing that is outside of bounds.

While on the other hand extraordinary claims need extraordinary evidence, but there is precisely nothing extraordinary here.

Jul 06, 2019
Changing its velocity vector's direction and increasing its speed without visible off-gassing is an extraordinary claim.

Anyhow, the real question is what star is it headed towards and would the present Newtonian mechanics line it up the putative rendez-vous at roughly the 60 degree angle to maximize another gravity assist?

Jul 06, 2019
Changing its velocity vector's direction and increasing its speed without visible off-gassing is an extraordinary claim.

Actually, it's not. As the paper points out:
The search for gas emission from 'Oumuamua was not comprehensive owing to the challenging observing circumstances. There were no observations that could have made sensitive enough detections of water outgassing to test for comet-like activity.

Jul 06, 2019
I don't see a link to the paper, so here's the arxiv version (probably a pre-print): https://arxiv.org...1910.pdf

Jul 07, 2019
'Nuff said. Ouamuamua is an alien probe from another galaxy who came to this Solar System looking for intelligent life. They found none. They have also been monitoring radio waves to see if plants or animals knew of their arrival. They ascertained that wolves were able to determine that their rock was actually a space ship from the Andromeda galaxy who came to check out the neighborhood to move approximately 10 billion of their own population to planet Earth.
They were counting on the humans living on Earth to regard their spaceship as a "rock", and the trick worked.
It is well known that humans of Earth fully expect that a real alien spaceship would resemble the starship USS Enterprise with at least one Klingon on board. Such is not the case, and an alien spaceship would have a better chance of not revealing its reality if in the form of a large rock. The Plan worked and humans are none the wiser. The first alien immigrants will be arriving in ~200 years. Get ready.

Jul 10, 2019
I skimmed through the ARXIV paper and thought it looked well done. Maybe the lesson here for the author is if you are going to refute an alien hypothesis you still need to explain why in far more detail than its proponents presented their cases.

BTW, from the paper, the "anomalous" acceleration (4.92±0.16)×10−6 M/s^2 or about 5 microns per second squared. Some outgassing after being cooked by the sun at ~0.25 AU is hardly surprising. Remember the inverse squared law? At 0.25 AU the sun is 16 times stronger than on Earth. This is inside the perihelion of Mercury, so ya, O got cooked and probably let off a little gas.

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