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Nailing the nature of "Oumuamua" is probably a comet, but …



The image of an extraterrestrial spacecraft from the film “Close Encounters of the Third Kind”.
Zoom / I mean, maybe right? May be? Probably not. Almost certainly not.

Shortly before Halloween, the chairman of the astronomy department at Harvard openly stated that an interstellar object rushing through our solar system may simply be part of an extraterrestrial spacecraft. And then … crickets.

Three days later, an astrophysics blog, Centauri Dreams, talked about cognoscenti. He presented a sound study of an academic document in which this obsessive opportunity was raised, supported by quotes and comments by co-author (as well as head of the department) Avi Loeb. It was good in November before exits, such as CNN, Time, and The washington post picked up the story, replete with inevitable sarcastic quotes and funny headlines. An object named "Oumuamua, had a number of strange and seemingly contradictory properties; perhaps these properties appear the way they do, because our observations are not so great. There are other possibilities.

I read an article by Loeb, which by then was quickly accepted for publication by respected Astrophysical journalA few days later, Loeb and I sat down at the longest and most famous story of Loeb – the most serious and detailed interview he gave on this topic. Built-in audio player after the colon at the end this sentence has hourly editing, including all the main points:

If you do not use sound in a spoken word, we have the transcript in both plain text and PDF format (which is probably a little easier to read).

"I do not say that they are aliens, but …"

Avi Loeb is clearly pacing one of the most unusual claims in astronomy. This, of course, requires extraordinary evidence – a requirement for which Lobe’s beloved title does not give him any exceptions. But we also need to avoid an upside-down answer to the knee jerk, which goes something like this: “Just because the chairman of astronomy at Harvard says this could to be an alien ship, that doesn't mean is an one; and in fact it means this not one because irony! Oh, and complacency too.

My interview with Loeb should not allow this debate in favor of aliens for you, me or anyone (Loeb himself needs much more evidence to get closer to the consideration of the case). But the story of "Oumuamua" is inherently fascinating. Digging into it, non-astronomers can not find out nothing or three about how the universe works. If you follow this path, you should keep in mind that foreign technologies were considered, and then ultimately omitted, as explanations of many astronomical phenomena. “Umuamua will probably join this list someday. But much is learned by pursuing claims, both in the field of astronomy and in the curious outsiders who follow this process.

If you listen to our interview (or read our probably OK-ish protocol), you will understand this discussion at a more subtle level than most people who score on it. And really cool? For the reasons that we discuss at the end of our conversation, the big issues here can be resolved immediately after 2022, when the new new telescope goes online.

For those in a hurry, I'll give a brief summary of our interview, labeled with time stamps to help you zip up the parts that interest you most.

There is something about & # 39; Oumuamua

Our story begins on October 19 last year (by tag Five to twelve audio interview is higher if you want to listen to more detailed information than is contained in this brief record). It was then that an object called “Oumuamua” was first discovered by the Pan-STARRS system of Hawaii, which tracks and detects near-earth objects.

Astronomers soon discovered that “Umuamua traveled too fast to link our Sun, which meant that it originated in a distant star system. This made it the first interstellar object finally identified in our solar system. The astronomical community, correctly intrigued, pointed to the apparatus in relation to the rebound. Thus, the masses of observational data were obtained before “Umuamua disappeared in sight in January.

The artist made an impression on the strange asteroid “Oumuamua”. Src = "https://cdn.arstechnica.net/wp-content/uploads/2017/11/1I_eso_artistimpression-640x400.jpg" width = "640" height = "400" srcset = "https: //cdn.arstechnica. net / wp-content / uploads / 2017/11 / 1I_eso_artistimpression-1280x800.jpg 2x
Zoom / The artist made an impression on the strange asteroid “Oumuamua”.

“Umuamua was strange on several fronts from the very beginning. Interesting is that he travels on the “local standard of rest” (timestamp 15:36) among our local collection of stars. For reasons explained by Loeb, this is a fascinating attribute — and an incredible (though not impossible) for a natural object.

June (timestamp 23:22), Nature published a rigorous analysis of the “Uumauama trajectory”. Its authors determined — with 30 standard deviations of trust — that an object accelerated when it retreated from the Sun. This was interpreted as evidence that it was a comet, and not an asteroid (another likely candidate). Thus, comets are accelerated in this way, driven by gases emitted by the heat of the Sun, which create their signature tails.

However, several observations contradicted this. (time stamp 25:44). For example, no tail was ever observed on the Uummuamua. There was also no coma (fuzzy comet head). There were no signs of water on it, and comets usually carry water. And “the reflectivity of the surface of Umuamua goes far beyond those associated with comets.

These and other quirks can be explained or justified by themselves. But for Loeb, the last straw was the September paper of the Roman Rafikov University of Cambridge (timestamp 28:39). It argues that the rotational speed of Uumauama (which was quite sharp — another oddity) remained constant throughout the entire observation period, while degassing should have greatly disturbed the spin.

Loeb came to the conclusion that degassing could not lead to the acceleration of the Uumamuama. He considered alternative forces and settled on one thing that astronomers understand quite well: the pressure of radiation emitted by the sun. But this is a much weaker force than degassing. If he was in charge, “Umuamua should have been a lot smaller than the estimated piece of mountain astronomers with a quarter mile plus. In particular, Loeb tied it as a diameter of up to 20 meters. And here clincher is less than a millimeter.

Close encounters of one kind or another.

No known natural process can produce anything remotely subtle in space. But it sounds very much like a sunny sail. And Loeb spent many long hours modeling the physics of solar sails, helping to lead the project “Breakthrough Starshot” by Yuri Milner (timestamp 18:55). Yes, the cliche about the owners of the hammer, taking the wrong nails for nails, instantly striking, and Loeb recognizes this (30:07). But, as you know, the Hammers accurately identify the nails.

The most exotic opportunity contained in the work of Loeb (33:55) lies in the fact that “Umuamua was on a target reconnaissance mission (not necessarily highlighting the Earth, but perhaps, generally traveling around the inhabited zones of star systems). This is based on inherited calculations regarding the relative abundance of interstellar objects and other factors.

Loeb and I then discuss the online archive, where he and his coauthor, postdoctoral student Shmuel Bialy, first publish their newspaper (36:58) and the extraordinary speed with which Astrophysical journal as accepted and published (40:35). Then I introduce Loba to the slaughter of some of his critics, to which he responds (44:51). This leads to a discussion of Loeb’s philosophy about the roles and responsibilities of scientists.

The unusual approach of the object suggests that it appeared outside our solar system. "Src =" https://cdn.arstechnica.net/wp-content/uploads/2018/06/Screen-Shot-2018-06-28-at-1.51 .22-PM-640x379.png "width =" 640 "height =" 379 "srcset =" https://cdn.arstechnica.net/wp-content/uploads/2018/06/Screen-Shot-2018-06- 28-at-1.51.22-PM.png 2x
Zoom / The unusual approach of the object suggests that it appeared outside our solar system.

We close the fascinating prospect that a large telescope, which debuted in 2022, can quickly answer questions that elude current equipment (56:56). This returns to an abundance of interstellar objects such as Oumuamua. If they are as rare as above, more powerful new equipment will find only a handful of new ones. But if they are common enough to make Umuamua discovery unsurprising, a new telescope should quickly detect thousands of them.

This argument is too involved to fully explore here (I'm a podcaster, not a journalist). Therefore, I urge you to listen to this section. This is all, but gives a controversial explanation for Loeb sale by date, and this date is a few more years away.

Personally, I can't wait to follow events as I get closer. Listen to this section and you will know the main problems, as I do. Be that as it may, there is at least a small chance that 2022 will bring sharp suggestive evidence that “Umuamua is an artificial relic. And whatever the result, wouldn't it be great to follow this story as it unfolds?

This interview is the latest episode of my podcast After On. If you like it, the full archive of my episodes can be found on my website or through your favorite podcast application by searching for “After On”. The wider series is built on deep-sea interviews with world thinkers, founders and scientists, and it is usually technical and scientific.


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