View Full Version : Star Probe

4th Nov 2018, 18:45

The first known interstellar object to travel through our solar system could be a gigantic alien solar sail sent to look for signs of life, according to a new study.

The mysterious asteroid Oumuamua (https://www.standard.co.uk/topic/oumuamua) has been analysed by astronomers from the Harvard (https://www.standard.co.uk/topic/harvard) Smithsonian Centre for Astrophysics (CfA) after it was found to be unexpectedly speeding up. NASA​ said earlier this year (https://www.standard.co.uk/news/interstellar-object-oumuamua-is-unexpectedly-speeding-up-leaving-nasa-scientists-baffled-a3875736.html) observations from their Hubble Space Telescope confirmed the object had an “unexpected boost in speed and shift in trajectory as it passes through the inner solar system”.

Scientists have now concluded that the asteroid “might be a lightsail of artificial origin” using solar radiation to propel itself forward.

The study (https://arxiv.org/pdf/1810.11490.pdf) said: “Considering an artificial origin, one possibility is that Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment. Alternatively, a more exotic scenario is that Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilisation.”

Professor Abraham Loeb, who carried out the study with Shmuel Bialy, told Universe Today (https://www.universetoday.com/140391/could-oumuamua-be-an-extra-terrestrial-solar-sail/): “Oumuamua could be an active piece of alien technology that came to explore our Solar System, the same way we hope to explore Alpha Centauri using Starshot and similar technologies The alternative is to imagine that Oumuamua was on a reconnaissance mission.”

Before he died, Professor Stephen Hawking said the most likely shape for an interstellar spacecraft would be a "cigar or needle" as this would “minimise friction and damage from interstellar gas and dust”......

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/968x645/setialienspacecraft_72e95111686273838cc2b555fb6041f69f00fbea .jpg

4th Nov 2018, 21:05
As long as it doesn't thump into the Caribbean we should be all right.

4th Nov 2018, 21:52
Like a child sipping a stone off the water

4th Nov 2018, 21:52
Oumuamua is Hawaiian for baguette.

4th Nov 2018, 21:55
Oumuamua is Hawaiian for baguette.
Is it sponsored by Subway?

4th Nov 2018, 22:03
Maybe it contains nuts !! :eek:

4th Nov 2018, 22:03
Star probe, that reminds me that I must make an appointment with my GP and his rubber gloves. :eek:

I have to admit that is an unusual shape for an asteroid. Rendezvous with Rama; Arthur C. Clarke springs to mind.

Loose rivets
4th Nov 2018, 22:04
using solar radiation to propel itself forward.

Which way is it going?

"cigar or needle" as this would “minimise friction and damage from interstellar gas and dust”......

Well, if anyone should know about the energy is such relative speeds (what else would they be but relative?) it is Professor Hawking. But flat, or needle sharp, I still don't want to run into average space particulate matter at anything over 10 thousand miles an hour, let alone .5 c.

Sending something to us? If you hold your arms out wide, and that's the galaxy, then how far have radio waves reached from Earth since we started transmitting? On that scale, about the size of a full stop/period on an A4/Letter page. Depressing isn't it? I hate being in a time prison.

4th Nov 2018, 22:51
Oumuamua is Hawaiian for baguette.

More likely from Umbongoland.

5th Nov 2018, 07:21
Von Neumann Machines - or Self Replicating Probes....


“........And indeed, these probes would be remarkably efficient. A recent study (http://io9.com/anything-self-replicating-is-likely-to-experience-repli-909883465) published in the International Journal of Astronomy pointed out that extraterrestrial intelligences (ETIs) could use the slingshot effect to propel SRPs from star to star. And yes, that's the same method used to propel the Voyager spacecrafts through our solar system from planet to planet. For it to work on a galactic scale, however, SRPs would use slingshot maneuvers around stars, gaining a boost in velocity by extracting energy from each star's motion around the galactic center. The slingshot effect would carry little-to-no extra cost and result in a 100-fold increase in efficiency; models show that this technique could be used to send probes to every solar system in the galaxy in as little as 10 million years......”

5th Nov 2018, 07:33
I’ve seen something like this before! :eek:


Loose rivets
6th Nov 2018, 01:10
A page of ramble and I hadn't addressed the OP's post. Oh, dear, but a lot of the thread is about making our, or our creations' way, about the galaxy. Trying to find investors with a multi-thousand year return time will be tricky. But who knows, they may sign on the dotted line a moment before being put in a cryo-chamber.

Pushing against the ultimate speed limit is, IMHO, futile. Spreading a form of intelligence throughout the galaxy? I'm just not sure what the motivation would be. The concepts of the need for policing etc., are fascinating but it occurs to me that this experiment has already taken place.

When I wrote The Perfect Code, I needed two things: an exquisite self-replicating mechanism for carrying a mind . . . and instantaneous travel. Well, on our planet, humans are part of the way back to perfection, but have a long way to go.

The math on the evolution of species? No need for me to do that, Fred Hoyle concluded there was not the slightest chance of the spontaneous creation of a self designing code and all its mechanisms in the available three and a half billion years. You doubt Hoyle? His publications on this subject are a hard, for me a very hard read. His science is superb, and it's a pity he's remembered by some as the bloke who believed in a solid state universe for so long. Oh, and coining Big Bang. He wasn't daft, his arguments were based on a very definite mechanism for the cosmological constant in his Field equation.

I postulate the creation of perfection first, the descent into reverse evolution to protect itself just part of a yarn. It used to drive Send Clowns potty, but it's the nub of my real thoughts. Darwin agonised over the eye, but had he known the recent findings of the glial cell functions, he might well have let his competitor's publication be the only one.

The 5th force. As I've mentioned before, I made it up and used it so much I almost called the book, simply, 5th. Might just as well have done. The Universe has a terribly slow natural speed limit and I doubt it will ever be bypassed, but who knows, the restriction is when we try to travel through spacetime, but if the fields are there in a structured form, maybe they can be displaced in a way that's instant - using the very energy contained in the fields. We couldn't make something do it by force, or with a force; the ability to command it to happen would have to be a basic part of the design of spacetime. We just need the key.

On my daily hike on the Naze cliffs I almost always think about gravity. 40 years of puzzling over it, and I can almost taste the mechanism. I picked a stone up today. Inside, the fire of gluon activity had probably been raging for billions of years. 96% or more of that stone is that energy. I think it's an energy that may be being fed, and the fuel is the inflow of spacetime - and of course that inflow is the prime, but not only, factor giving us the pseudo-force we call gravity.

Watch this space


6th Nov 2018, 08:01
We don’t get anything back except for knowledge by spending hundreds of billions exploring the solar system - but still we do it. The plans are already there for nano-sized starships within the next few decades, I think we will do that as well.

Will we eventually send Von Neumann probes? I think equally probable.

As for human exploration, the problem is our ephemeral lifespan. But if a means of ever uploading our consciousness into cybernetic hosts is so,fed then that issue goes away - and you can eithe4 sleep or slow down the speed of thought so the journey time spent seems much shorter.

There is a good Sci-Fi series based on the concept - The Bobiverse......


6th Nov 2018, 08:37
I'm sure they had a good laugh on the way past. Thought about stopping but...

7th Nov 2018, 08:01

Could ‘Oumuamua be an alien lightsail?

When the object now known as ‘Oumuamua was first discovered (https://earthsky.org/space/a2017u1-comet-asteroid-interstellar-beyond-solar-system) a year ago, it caught astronomers by surprise. It’s an oddly elongated, tumbling object whose orbit indicated it came from outside our solar system. Although interstellar objects – natural objects like comets or asteroids that move between solar systems – had been expected, no object like this one had been seen before. So what was it? Scientists and others immediately began speculating and devising theories. Asteroid? Comet? Shard of a destroyed planet? On November 1, 2018, a new paper was released that raises again the possibility that ‘Oumuamua might be artificial – something like a lightsail or solar sail (https://en.wikipedia.org/wiki/Solar_sail), a spacecraft whose propulsion method is the radiation pressure (https://en.wikipedia.org/wiki/Radiation_pressure) or “wind” from stars.

Shmuel Bialy (https://itc.cfa.harvard.edu/people/shmuel-bialy) and Abraham Loeb (https://www.cfa.harvard.edu/~loeb/) at Harvard Smithsonian Center for Astrophysics are co-authors on the new paper (preprint here (https://arxiv.org/pdf/1810.11490.pdf)).

7th Nov 2018, 13:23
If it were of artificial design, I wonder what advantage tumbling through the ether has ? To my simple mind this would make the risk of collision with small particles/debris greater, than in a 'streamlined' position. I suppose tumbling might reduce exposure to radiation emitted from stars etc, sharing the dosage over the whole body.

7th Nov 2018, 13:40
One of the points in the paper is that th “tumbling” is an artefact of the tracking radar/telescope and a similar signature would be given from the ticking of a light sail across the solar wind.

”...... have shown that the observed non-gravitational acceleration of ‘Oumuamua, may be explained by Solar radiation pressure. This requires a small mass-to-area ratio for ‘Oumuamua of (m/A) ≈ 0.1 g cm−3.........

While our scenario may naturally explains the peculiar acceleration of ‘Oumuamua, it opens up the question what kind of object might have such a small mass-to-area ratio? The observations are not sufficiently sensitive to provide a resolved image of ‘Oumuamua, and one can only speculate on its possible geometry and nature. Although periodic variations in the apparent magnitude are observed, there are still too many de- grees of freedom (e.g., observing angle, non-uniform reflectively, etc.) to definitely constrain the geometry. The geometry should not necessarily be that of a planar sheet, but may acquire other shapes, e.g., involving a curved sheet, a hollow cone or ellipsoidal, etc.......

Known Solar System objects, like asteroids and comets have mass-to-area ratios orders of magnitude larger than our estimate for ‘Oumuamua. If radiation pressure is the accelerating force, then ‘Oumuamua represents a new class of thin interstellar material, either produced naturally,through a yet unknown process in the ISM or in proto-planetary disks, or of an artificial origin.

Considering an artificial origin, one possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment. Lightsails with similar dimensions have been designed and constructed by our own civilization, including the IKAROS project and the Starshot Initiative.......

This would account for the various anomalies of ‘Oumuamua, such as the unusual geometry inferred from its lightcurve, its low thermal emission, suggesting high reflectivity, and its deviation from a Keplerian orbit without any sign of a cometary tail or spin-up torques”......

7th Nov 2018, 18:05
Sounds like the opening scene in Larry Niven's The Mote in God's Eye.
A very good read if you ever get the chance.

Loose rivets
7th Nov 2018, 20:10
As for human exploration, the problem is our ephemeral lifespan.

Unless of course we reawaken after this lifetime with even just a hint of memory from this existence.