That Interstellar Asteroid Is Pretty Strange

http://blogs.discovermagazine.com/outthere/2017/11/23/interstellar-asteroid-mystery/

by okket • 9 years ago

143 66 9 years ago

blogs.discovermagazine.com

wruza• 9 years ago

Say whatever you want, I know it is Silkie spaceship.

michaelwiliamd• 9 years ago

It’s also our first direct look at an intact visitor (as opposed to dust specks) from another solar system.

Would it not be possible to calculate the origin system based on speed, trajectory, star positions?

rothbardrand• 9 years ago

I don't think so... it slungshot around the sun, which implies that its in a very large sun oriented orbit. (eg: some random object passing bit for the first time would be likely only slightly disturbed by the suns gravity, not coming so close to it... the latter seems to imply it has been caught by the suns gravity.... or just happened to be aimed nearly directly at the sun.)

Taniwha• 9 years ago

No, they distinctly say it is hyperbolic, not an ellipse, so not orbiting the sun

dangerbird2• 9 years ago

The problem is that the star positions change over time via galactic orbit. 'Oumuamua's trajectory appears to originate from Vega, but Vega would have been at a different position in relation to our solar system back when 'Oumuamua was at the same distance from the Sun as Vega.

QAPereo• 9 years ago

Not only is the system in question dynamic, as another pointed out, but also subject to perturbations. Worse, orbital mechanics with many bodies is chaotic, in the strict sense.

singularity2001• 9 years ago

tell me it's no the vanguard of a galactic police squad coming to arrest humans for universal misconduct

DanielleMolloy• 9 years ago

Here is the random astronomer on Reddit claiming that the community didn't rule out that it is an abandoned spaceship yet: https://amp.reddit.com/r/space/comments/7ealls/solar_systems...

"Astronomer here! I will never say this lightly, but we are, swear to God, actually discussing with some seriousness right now what are the odds that this was actually a spaceship. Which I 100% assure you has never happened before in my memory with seriousness."

erikb• 9 years ago

Why the hack do you assume it's abandoned? It can be full of lifeforms even and we are just not able to see them, talk to them, etc. Imo at this point any assumption is closing in too much. We don't have a definiton of "life" that for sure would include extraterrestrial lifeforms that are not actors with masks in star trek, right?

paulmd• 9 years ago

Well, it's tumbling end-over-end which suggests that if it's a spaceship, it's no longer in control.

The discussion around the possibility of it being a spaceship rests on the idea that long thin cigar-shaped objects are the most efficient way to travel in space because it minimizes your need for ablative protection from interstellar dust/etc. But if you're tumbling end-over-end you've thrown that advantage away, so presumably that's not a thing you would intentionally do. And if you are assuming that this spaceship has shields or whatever, then there is no reason they would be restricted to a cylindrical shape.

It could be a discarded booster stage or fuel tank, of course. Maybe they were trying to drop it into the sun and missed. Or a a mass-driver shot (maybe they finally took care of that pesky Russell's Teapot for us...)

The presumptive conclusion is of course that it's a natural phenomenon, but it sure is a weird object, and unless we can find a way to catch it (or any future objects) we will never know. Maybe a starshot probe could catch it?

zodPod• 9 years ago

This has always been my argument too! I understand that scientists want to start with what they know to narrow stuff down but is it not entirely possible that there's life on a planet that just doesn't work like ours? Obviously the organic structures that we're familiar with need a certain series of parameters to survive but that doesn't mean that any other kind of object couldn't end up being a sentient being.

valuearb13• 9 years ago

It’s really traveling far too slowly to be a viable interstellar transport.

i_am_nomad• 9 years ago

What does “viable” mean, though? For us, it might not be viable, but for organisms that live on a different (or even variable) time scale it might be just fine.

tempay• 9 years ago

Is that still the case if it intends to stop in our solar system?

dguaraglia• 9 years ago

"Rendezvous with Rama" theorized such an incident. Shame we spent too much of the last century blowing each other to smithereens rather than developing the technology to figure it out for sure.

api4• 9 years ago

Well hey... It's possible. Not likely but possible.

It could be a dormant long term hibernation ship en route somewhere. Computing it's trajectory would be a way to look at this. Very long term deep hibernation would be one very plausible way to go to the stars.

It could also be a ship that malfunctioned and died millions or even billions of years ago. If it were traveling very fast it could play stellar gravity ping pong for a long time until eventually settling into an orbit, hitting something, or being ejected from the galaxy. Picture some insectoid alien mummies playing silent vigil in cold intergalactic space until the heat death of the universe and bust out the theramin.

Whatever it is I wish NASA could cook up a flyby. A light small prove could probably get tossed on a high enough energy trajectory to catch it and take some pics. Surely the first extrasolar object is interesting.

Edit: elsewhere several people pointed out that a tumbling object like this might not be an interstellar ship/probe but a spent expendable acceleration stage for one.

valuearb13• 9 years ago

If it's a spent stage, then the parent vehicle is also traveling very close to 26 KM/sec and is already here.

sailingparrot3• 9 years ago

Occam’s Razor says it’s unlikely that the very first object we ever see from interstellar space just happens to be a spaceship.

Well, isn't this kind of self fulling thing?

Because we assume first that this is an interstellar asteroid, then the following statement is "proven":

Researchers had long theorized that space should be full of comets and asteroids ejected from other solar systems during their early days. Their models showed that planetary formation is a messy business, with many small objects kicked out as big proto-planets form. `Oumuamua is the first proof that they were right

And at this point, yes, it appears very unlikely that the first interstellar object we meet would be artificial.

But if we start by saying we don't know what it is, then the above theory is just speculation, and might be false (what if planeraty formation is a clean process?). If the theory above can be false, then it could make sense that the first interstellar object we encounter would be artificial, no?

It seems to me that Occam's Razor doesn't tell us much in this instance.

nuclx• 9 years ago

What I thought. The absence of a priori knowledge prohibits the application of Occam's Razor in this case.

hyperpallium• 9 years ago

Unfortunately, Occam's Razor can say whatever you want by fiddling the apriori probabilities. Here, the probability you need is how likely that theory is to be true - just because it could be false doesn't mean it's 50-50.

If all the models show planet formation is messy, it seems reasonable to estimate its probability as much greater than 0.5 (note that even if it's 0.9999, they still could be wrong).

sailingparrot3• 9 years ago

Totally agree. My point is just that I find it a bit weird/circular to use Oumuamua as the `first proof` for a theory that is subsequently used with Occam's Razor to demonstrate that Oumuamua is likely not something else.

AdamJacobMuller2• 9 years ago

Exactly what I was thinking reading this article.

Perhaps Oumuamua is a piece of evidence that fits this theory, but, is it really the first one? If it is the first one, it hardly proves the theory. At this point (from what I can see) we have a sample size of 1 (Oumuamua). Now, we also haven't been watching for very long (10 years or so where we could track this sized object) and aren't watching too much of the sky, but, this still doesn't prove anything.

hectorlorenzo• 9 years ago

These actually sound like last famous words.

joering2• 9 years ago

What's really shocking is the drawing from the article [1]

This Astroid was Discovered when already passed by the Earth!!

And was actually very close to it! While I am pretty certain Astronomers knew it won't hit us, the amount of time it took to discover it would be way too late for us to even hold hands and kiss our children goodbye!

http://blogs.discovermagazine.com/outthere/files/2017/11/eso...

grkvlt2• 9 years ago

Well, if it had hit Earth, it would have happened without astronomers (or anyone else) knowing about it beforehand. As you point out, it was discovered after it had passed us, so there was no advance warning at all, however this is quite common with asteroids.

valuearb13• 9 years ago

The earth gets hit by similarly sized asteroids every 30,000 to 100,000 years, albeit not quite at this velocity. Average impact velocity for asteroids from our system is 17 Km/sec, so about 2/3s the speed of this visitor. Either way, it's not even close to an extinction event.

And "very close to it" is a misnomer. It came within 24 million kilometers of Earth, about 60 times farther away than the moon is.

jfindley• 9 years ago

Are there yet any credible theories for why we see so few of these? AIUI, if we're correct about how planets form, there should be far more of these than we're seeing. Is it that we're probably wrong about how planets form, or there's something strange about our part of the galaxy, something else or do we just have no clue?

dr_zoidberg• 9 years ago

The general consensus amongst astronomers is that these objects are far too faint to be seen. As more sensitive instruments are developed/deployed, we should begin seeing more of them.

sailingparrot3• 9 years ago

Estimate is that there might be about ~10 of these object passing through every year, so it's not a lot to start with. In addition asteroids are relatively small and hard to spot since they are inert. We managed to spot this one because we were lucky it came so close to earth.

splittingTimes• 9 years ago

So why exactly can we not get a better look at it as it is leaving? With all our earth- and spacebound telescopes [1] (some are sitting at Earth-Sun Lagrange points) I would imagine we could. Being too far away behind the sun seems an unlikely argument to me.

===

[1] https://en.wikipedia.org/wiki/List_of_space_telescopes

grkvlt2• 9 years ago

The only working telescope at a Lagrange point is Gaia [0] at Earth-Sun L2, but it is an astrometry instrument, designed to measure the position and brightness of various stars, rather than generic deep-space imaging. The Herschel Space Observatory [1] is also at the Earth-Sun L2 point, and has a 3.5m IR telescope, but ran out of coolant in 2013 and is now defunct. Interestingly, these are both ESA missions, not NASA.

0. https://en.wikipedia.org/wiki/Gaia_(spacecraft)

1. https://en.wikipedia.org/wiki/Herschel_Space_Observatory

rsynnott• 9 years ago

NASA was involved in Herschel to an extent.

kirykl• 9 years ago

Seems like this is the same problem/discussion a distant civilization would have with Voyager

oscargrouch• 9 years ago

Or it would become a sentient being somehow while in deep space and haunt us back in 2271.

V'GER ..

kk_cz• 9 years ago

Voyager is much smaller, though. Can someone with relevant knowledge tell us if this object would be still detected if it was the same size as Voyager 1?

scruple• 9 years ago

Would we have detected a Voyager-size or Voyager-like object entering our solar system? I really, really doubt it.

arnaudsm• 9 years ago

Relevant XKCD : https://xkcd.com/1919/

Santosh833• 9 years ago

Is there any possibility we could launch a really fast space probe that could overtake this object and report back, maybe within the next decade or so? Do we have the technology now to pull alongside this rock (and it's going to be slowing down)?

api4• 9 years ago

Probably. Strap a big overpowered upper stage behind a little lightweight payload and you can fire something pretty fast.

valuearb13• 9 years ago

Unfortunately it's almost impossible at this point. The object passed pedigree a while ago and is headed back out, earth is in a very poor position for an intercept. The calculations I've seen say even if you use the largest possible booster, the SLS (which doesn't exist now, won't exist for another 3 years, if ever) it couldn't even get a small probe to catch up for a very long time, if ever.

There may be options in using Jupiter for slingshot maneuvers to overcome our bad positioning, and using super advanced hall effect motors, or project slingshot type probes. But it seems pretty slim at this point.

UPDATE: The reddit thread has this comment "Not a chance. Velocity relative to the sun is presently > 39 km/sec and relative to the earth is > 64 km/sec. This is far faster than anything we have ever launched or even could plausibly launch in the near future".

Which explains why you need Jupiter to redirect your probe so you can have it go only 40Km/sec to catch up, rather than 65 Km/sec direct from earth.

wiml• 9 years ago

I've seen a couple of suggestions for ways we could theoretically catch it. One is high-Isp rocket motors, which I think would have to be nuclear-thermal like NERVA. If we had one of those already lying around, it might be possible to catch up.

The other possibility I've seen discussed are extremely lightweight probes — chip-scale probes weighing less than a gram — accelerated by zillion-gigawatt laser arrays on Earth (or maybe in low Earth orbit). Since those probes don't have to carry their own fuel, they can reach much higher speeds, a sizable fraction of the speed of light, and could catch up to 'Oumuamua even if it took us a few years to develop the technology.

Neither of those are technologies we have (though we did build and test some NERVA prototypes back in the day) but they are things that we, as a civilization, could plausibly develop.

That Interstellar Asteroid Is Pretty Strange

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