Rendezvous With Rama ?

[toucana]

Oumumua - artist representation

In an intriguing parallel with Arthur C. Clarke’s sci-fi novel Rendezvous With Rama, Seti researchers now plan to use a powerful telescope to study an unusual space object which recently flew into our solar system.

http://www.independent.co.uk/life-style/gadgets-and-tech/news/oumuamua-alien-spacecraft-proof-life-seti-breakthrough-latest-asteroid-ship-a8104771.html

In Clarke’s original 1973 tale, astronomers become excited when a large new asteroid is detected in the outer solar system. It has an abnormal light curve which indicates it is spinning and has a long thin cross section. The astronomers who had long ago exhausted Greek and Latin mythology and are now working through the Hindu pantheon christen it Rama.

The object turns out to be a giant hollow cylinder, a space-ark from an alien civilisation far outside the galactic plane.

In real life, scientists have christened the latest visitor Oumuamua, a Hawaian word meaning ‘scout or messenger’, because it was astronomers from an observatory in Hawaii who first spotted it.

The mysterious needle shaped object is our first visitor from another part of the galaxy to make it into our solar system. It flew past in October and the trajectory indicates it entered our solar system from almost 90 degrees above the orbital plane of our system

It is long and cigar-shape. While it is hundreds of metres long, it's only one tenth as wide – and it is very unusual for asteroids to come in such non-round forms.

The body is travelling quickly through the universe, at up to 196,000mph, and looks as if it will not get wrapped up in our sun's gravity but fly right through and out of the solar system.

The Breakthrough Listen team is using the Green Bank radio telescope in West Virginia, US, to study Oumuamua.

The object is currently about two astronomical units (AU) from Earth, or twice the distance between the Earth and sun.

Lead scientist Dr Andrew Siemion, director of the Berkeley Seti Research Centre in California, said: "Oumuamua's presence within our solar system affords Breakthrough Listen an opportunity to reach unprecedented sensitivities to possible artificial transmitters and demonstrate our ability to track nearby, fast-moving objects.

Even if no evidence of extraterrestrial technology is found, the search could provide important information about gases surrounding Oumuamua or the presence or absence of water, say the researchers.

"On far-off Earth, Dr Carlisle Perera had as yet told no one how he had woken from a restless sleep with the message from his subconscious still echoing in his brain: ‘The Ramans do everything in threes’ - (Rendezvous With Rama)

[TheVat]

Yes, I thought of Clarke right away when I first saw the graphic a couple weeks ago. Am not sure the "non-round form" is quite as unusual as the article suggests. Rocks of that size don't have enough mass to induce them towards the rounder shape. Slivers of irregular shape break off and retain that shape, AFAIK.

[JMP1958]

Of course Rama was 54 km long with a diameter of 20 km and rotated along its long axis fast enough to create a significant artificial gravity effect for its interior. Oumuamua is 180 meters by 30 meters, and tumbles end over end at a rate so slow, that even if it were hollow, standing at the ends would not be, for most practical purposes, much better than being at zero g. ( you would be experiencing 0.0023g, meaning a 160 lb person would weigh a bit under 6 oz)

[toucana]

All hailing frequencies are open captain

The Seti Breakthrough Listen team have scanned Oumuamua with their radio telescope across four major frequency bands ranging from 1 gigaherz to 12 gigaherz capturing 90 TB of data in the first two hours alone.

https://news.sky.com/story/unidentified-space-object-not-alien-ship-say-scientists-after-first-scans-11171075

The scientist says that so far they have detected no evidence of artificial signals emanating from the object - not even in Klingon sadly.

"Infuriating!" screamed the Kzin, "Insulting. They deliberately ignore us. They pointedly turn their backs to invite attack".
"They do not use lasers, they do not use radio,.They do not use hyperwave. What are they using for communications? Telepathy, written messages, big mirrors ?"
"Parrots" Louis suggested.. "Huge parrots specially bred for their oversize lungs. They're too big to fly.They just sit on hilltops and scream at each other." (Ringworld - Larry Niven)

[TheVat]

"In space, no one can hear you....demand a cracker."

[toucana]

The Oumuamua asteroid which intrigued astronomers and delighted Arthur C. Clarke fans in December last year is back in the science news today after two scientists published a new arvix paper about the object under the auspices of the Harvard Smithsonian Center for Astrophysics in which they ask the question, was the Oumuamua object possibly an alien probe after all ?

https://arxiv.org/pdf/1810.11490.pdf

The two scientists named Shmuel Bialy and Abraham Loeb focus on the peculiar orbital behaviour of Oumuamua as it passed through our solar system at high velocity. Basically it sped up and accelerated on its way out in a manner that is rather difficult to explain in terms of the known orbital mechanics of its transit, unless you postulate a possibility that Oumuamua might effectively have been powered by a light sail.

The implications of this suggestion are rather fascinating, because as the authors explain, in order for the numbers to work, the object would require a very low mass to area ratio with a thickness of barely 0.9mm. They describe one possible geometry as that of an extreme oblate spheroid which in simple terms would mean something resembling a large pancake. The authors spend some time analysing the tensile strength of the material that would be required, and whether such an artefact could stand up to spin and tidal forces, and survive damage from collisions with interstellar dust, long enough to complete a voyage of any real significance.

The speed of Oumuamua’s passage through our solar system was so fast that astronomers weren’t able to image it in any meaningful way. The artistic representations of Oumuaumua as an elongated cigar were just that - artistic impressions. It’s real geometry could have been quite seen as quite different had we been able to observe it properly.

When Oumuamua was first detected in our system, it was studied by researchers from the Breakthrough Listen project using a radio telescope, but they captured only Gigabytes of silence. But other scientists now say that the radio silence doesn’t preclude a possibility that Oumuamua might have been a fully functioning probe sent by an alien civilization.

https://www.independent.co.uk/life-style/gadgets-and-tech/news/oumuamua-alien-spacecraft-proof-harvard-paper-latest-discovery-research-a8619116.html

"One possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment", the authors claim, and it might be unused debris that has been thrown out into space from a planetary system.

Such an explanation would account for the various strange characteristics of Oumuamua, including the unusual shape it seems to have.

Oumuamua is now too far away from Earth for scientists to understand any more about it. But more could be found by looking into the solar system for more objects of this type, the authors say. The scientists will have to hope that if Oumuamua was an alien artefact, that its makers , like the Ramans in Arthur C. Clarke’s novel- “Do everything in threes”

[TheVat]

Yeah, I saw Bialy and Loeb paper today, was going to post it here. IIRC, some other scientists have poo-poohed the ET probe idea because of the object's tumble. A probe would likely have some attitude control so that it could effectively train sensors on Earth and any other object it was studying. And also to keep any lightsail properly directed. Such a pronounced tumble is usually indicative of a natural chunk of debris.