The first known object to enter our solar system from deep space
cbc.ca
cbc.ca
True, it doesn't tell us as much about the nature of the universe as the discovery of the Higgs boson, and it doesn't represent a major advance in engineering like gravitational wave detection. But it is the only chance we have ever had to directly view a largeish piece of another solar system, just millions of miles away. The next time probably won't come until we send a probe to Proxima Centauri.
To me, the thought of an asteroid being hurled out of the solar system that created it, then traveling through the cold void for millions or possibly billions of years, and then whipping around the sun (a mere 0.25 AU distant) is just the most incredible thing. The whole world should be having parties in its honor, to wish it well as it leaves us behind. (Instead of just fighting each other over nothing, as we usually do.)
This is an amazing time to be alive.
Well, I don't know about that. Who's to say how many interstellar objects pass through the solar system every year (earlier I read 1-10 a year, but who knows). Of course this is the first one we've actually detected (Roswell et al. jokes here), but our sensors and technology are only getting better. Even if Breakthrough Starshot[1] can launch in 10 years, and takes 25 years to get to the Alpha Centauri system, and we get usable data back in 4.37 years, that's ~40 years we'd have in which to detect another interstellar object here first.
EDIT: Also see the sibling comment[2] by nkurz[3].
[1] https://en.wikipedia.org/wiki/Breakthrough_Starshot
After 8 years Oumuamua will be 6.64 billion km away (at 26.32km/s). A Starshot prototype probe flying at 1500km/s (0.5% of lightspeed c) could reach that distance in 51 days.
Starshot hopes to achieve 20% c eventually.
https://en.wikipedia.org/wiki/%CA%BBOumuamua#Potential_space...
> The Initiative for Interstellar Studies (i4is) has studied potential options for sending a spacecraft to 1I/ʻOumuamua, perhaps using first a Jupiter flyby followed by a close solar flyby at 3 solar radii in order to take advantage of the Oberth effect. More advanced options of using solar, laser electric, and laser sail propulsion, based on Breakthrough Starshot technology, are also considered. The problem is to get to the asteroid in a reasonable amount of time (and so at a reasonable distance from Earth), and yet be able to gain useful scientific information. If the craft goes too fast, it would not be able to get into orbit or land on the asteroid and would simply fly by it, moving at many asteroid diameters per second. The authors conclude that, although challenging, an encounter mission would be feasible using near-term technology.
Of course once 0.05c Starshot becomes feasible, there's a whole solar system to explore!
While this is the only one we've seen so far, the current belief is that similar objects might actually quite common. A parallel newspaper article in the Guardian [1] cites a paper out of UCLA [2], and works through the math:
The other group of astronomers, led by David Jewitt,
University of California Los Angeles, estimated how
many other interstellar visitors like it there might
be in our solar system.
Surprisingly, they calculate that another 10,000 could
be closer to the Sun than the eighth planet, Neptune,
which lies 30 times further from the Sun than the Earth.
Yet these are currently undetected.
Each of these interstellar interlopers would be just
passing through. They are travelling too fast to be
captured by the gravity of the Sun. Yet it still takes
them about a decade to cross our solar system and
disappear back into interstellar space.
If this estimate is correct, then roughly 1,000 enter
and another 1,000 leave every year – which means that
roughly three arrive and three leave every day.
[1] https://www.theguardian.com/science/across-the-universe/2017...
To me this is the most exciting part of the discovery. Previous research was quite pessimistic about our ability to observe these kinds of interstellar comets[1]. Finding the few interstellar comets among the many objects within our solar system requires effort and specialized methods. Since our previous estimates indicated that we would not be able to observe many of these interstellar comets, it did not seem like looking for them was worth the effort. Now that has changed.
Since previous estimates indicated that this discovery should not have been likely, we can be reasonably sure that previous estimates were incorrect. Meaning it now seems worth the effort to begin looking for them.
With the LSST[2] coming online in the next year or so, our ability to observe such objects will be dramatically improved over current telescopes including Pan-STARRS which discovered this one.
[1] (Disclaimer: I am an author of a previous paper which concluded that these kinds of discoveries would be nearly impossible with current telescopes. Never have I been more happy to be wrong) My paper along with several others are referenced in the Nature letter.
On most meteorite and asteroid science in the field, take it all with a grain of salt. There's not much data and they are pretty 'dark' as objects (low albeido, low mass/gravity, long periods, very tiny in a telescope, etc). Mostly, they are guessing at stuff. It's kinda funny how worked up they get over pretty much no data (as compared to other astro disciplines).
That said, extra-solar objects are super cool, bust mostly from an isotopic % standpoint. We then infer a lot from that stuff.
I am the average person when it comes to this subject. It is just that we (the avg people) do not understand what this means.
Some tantalizing points from the paper:
- They constrained the aspect ratio in two dimensions to be 10:1:C, but the third dimension is unconstrained. Depending on which axis the object is rotating around, C could either be 1, or 20. Either of these would be an essentially unique object within the solar system. This is a really weird shape.
- If the object is rotating around its short axis, it must have internal tensile strength (ie, it's a solid object, not just a pile of dust/gravel accreted by gravity). Lower bound on the required tensile strength is 3 Pascal (very little).
- There is essentially no dust/ice on the object - less than 1 kg within 2.5". So it's not a comet, and would have to be asteroidal. This conflicts with our current understanding of what objects would be in interstellar space. Current models have almost all objects ejected from our system being icy comets. This object would be analogous to a Manx comet, ie a rocky asteroid in a highly elliptical long period orbit.
- The shape of the observed light curve deviates from the best-fit triaxial ellipsoid in a way that suggests large flat or concave sections. It would take unrealistically large albedo variations to produce the same deviation without flat/concave sections.
And of course, of all the planets in the solar system, it made its closest approach to Earth, an astronomical "near miss" at just 0.16 AU :)
That is presumably because there’re lots of these objects, but we can only detect the ones closest to us.
- tensile strength (it should be cartwheeling, there is a physics theorem which means everything tends to this configuration)
- large flat or concave sections.
- others are reporting it's mostly metallic.
I'll say it: did anyone consider an alien spaceship? The paper seems to deduce "asteroidal" by ruling out other things, rather than by a positive measurement of rock spectra, unless I've misread it.
So you're saying it's a bio-ship! ldenneau confirms it's aliens!
Perhaps someone has discovered warp drives (is gravitational wave detection the first step) and the Federation have sent a ship to observe us.
Anyways, given all the EM radiation we're tossing out into the void, some species' probe out there is going to pick up our existence sooner or later.
And at ~395 earth-moon distances it's difficult to imagine how effective a 400-meter object, disguised as an asteroid, would be at seeing much detail on earth.
But it is tantalizing and fun to imagine--the appearance of a gravity boost... Flat surfaces... Near to earth... Lack of any ice or outgasing, a solid object, many characteristics not seen in other known-asteroids, rotating on its long axis... :)
Ah, but it's a carrier for the small, stealthy probes!
Is there a point where you, as a sober professional, start to entertain outlandish theories about something like this? Has this crossed that threshold?
That's what they want you to think!
https://www.popsci.com/interstellar-object-solar-system#page...
See some interesting back-and-forth on this here: https://www.reddit.com/r/space/comments/7ealls/solar_systems...
So maybe we can expect it to spin (and/or see it doesn't and speculate on the reasons for that)
What about elastic bands 100s of kms long? Probably no material strong enough, elastic or not.
You harpoon the object, then let it pull the probe, giving lots of slack according to the engineering tolerances of the harpoon in the object (don't want it to come loose), the tether (don't want it to snap), the reel (don't want it to spin apart or get stuck or any one of a number of things), and the probe (don't want it damaged under extreme acceleration).
With enough tether and a low-enough-friction reel with magnetic bearings (think of the ungodly RPMs), you can accelerate the probe at almost any speed you'd like, within reason, although it would be best to accelerate as quickly as possible without risking. And remember that you only need to get the whole harpoon/tether/reel (HTR, or HiTchhikeR; you saw it here first) mechanism in range of the object as it passes by, so it can be bulkier than you would put on a probe moving under its own power. Or you could start off as usual, maybe with a gravity assist, which would allow for a less sophisticated HTR.
Then if you want to be clever, you can turn all those RPMs into stored energy. But that might not be worth the trouble.
A harpoon impacting an object going 26km/s would experience something like 12,000gs even if you gave it a 1km-long buffer.
So your harpoon would have to be rocket-assisted. The problem now is how long does your need to be? The tensile strength to carry the weight of the tether itself may make this impossible.
Certainly, for now and a while to come.
Edit:
Looked at the paper and saw this in the abstract:
>None of the approximately 750,000 known asteroids and comets is thought to have originated outside our Solar System, but formation models suggest that orbital migration of the giant planets ejected a large fraction of the original planetesimals into interstellar space1.
Very interesting that this has been the thought of affairs for objects in our solar system. I have never contemplated it and just assumed we must have been visited before by such objects.
Can't help but think of the Chindi!
https://futurism.com/the-sun-just-killed-the-fastest-moving-...
[1] https://www.amazon.com/Three-Body-Problem-Cixin-Liu/dp/07653...
Plus there's the issue of actually getting into position in time to setup all the maneuvers required to match the speed.
But we didn't do that, and that means, well, let's just say things are going to get rather interesting.
F you artists concept. Drawing fantasy pictures in news messages is not ok.
+ I'm no grammar guy, nor a native speaker, but "artists's" is wrong, isn't it?
In fact, the possessive "'s" is a leftover from Old English, where the inflectional suffix "es" marked the genitive case.
You are aware that astronomers and universities and even NASA regularly collaborate with such artists to create photorealistic simulations of planets, moons, and similar objects, and that lots of information and striving for accuracy goes into making those pictures right?
Plus, when they say "artist" they don't mean they asked some Picasso to make a drawing of the object for art's sake, but tasked someone (graphic designer etc) to make a realistic depiction of it given the data they know.
People take away this artistic images and believe the world is like this, but it isn't. Same with WW2 movies, people believe war is like in these movies, it isn't. But in one case it's hollywood, in the other case it's a news outlet.