[Cal___]

I think it's a shame that this story hasn't gotten more attention.

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.

[nkurz]

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.

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.

So now that we now to look for them, it may be possible that we'll be able to find others, at least before the probe reports back from Proxima Centauri.

[1] https://www.theguardian.com/science/across-the-universe/2017...

[2] http://www2.ess.ucla.edu/~jewitt/papers/2017/JLR17.pdf

[nathanielc]

> So now that we now to look for them, it may be possible that we'll be able to find others, at least before the probe reports back from Proxima Centauri.

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.

[2] https://www.lsst.org/

[eru]

Seems very similar to when they found the first exoplanets. The first few were big news, and now they are routine.

[Balgair]

SO worked with Dave and his lab while in grad school. On this stuff, Dave is right, trust him.

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.

[sandworm101]

If so many are passing through, and have been doing so for millions/billions of years, then at least a few thousand must have been captured. Line up the right planet and even a high-inclination object can be slowed enough to be trapped. It would be an interesting exercise to calculate what percentage of high-inclination objects might actually be alien.

[pqh]

Would it still be travelling too fast to be captured if it hit the sun directly?

[macintux]

Is something technically captured by a gravity well if it just happens to hit the object at the center? I assume not.

[isoprophlex]

At the very least, I'd say that... after collision, assuming complete coalescence into the object, they will share identical orbital parameters

[JshWright]

It would cease to exist in that case...

[eru]

No, but that's exceedingly unlikely. Even the sun is a very tiny target.

[Cyphase]

> The next time probably won't come until we send a probe to Proxima Centauri.

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

[2] https://news.ycombinator.com/item?id=15746491

[3] https://news.ycombinator.com/user?id=nkurz

[Tepix]

Breakthrough Starshot could use I1/Oumuamua as a test object once they got some prototypes ready:

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.

[Cyphase]

Oh yea, I was going to mention this; thanks for the reminder.

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!

[Tepix]

Sure, it will zip past a 500m object in a fraction of a second. Then again it will also zip by a planet in less than a second at 60,000km/s (20% c). They might as well solve that problem in the next 8 years.

[kobeya]

You might like the book Rendezvous with Rama.

[Timothycquinn]

I liked the whole Rama series. When I heard of the suggested dimensions of this object, I immediately thought of Rama.

[ISL]

Everything in threes.

[cperciva]

It might not tell us as much about the nature of the universe, but good observations of this and future visitors could tell us a lot about the nature of other solar systems. So far we've generally assumed that solar systems are pretty similar in how they form, without much evidence beyond a few simple models; seeing debris from other solar systems could do a lot to confirm or refute that hypothesis.

[rokhayakebe]

it's a shame that this story hasn't gotten more attention.

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.

[logiclion]

What it means is that we are a tiny speck of dust floating on a tiny rock in space and an object that has come from a distance that is so far away numbers wouldn't do it justice has just flew by earth closer than the distance between the earth and sun (1 AU). Some quick facts (from wikipedia), 100 years ago it was 561 AU away (Neptune is ~30 AU), its max speed was 196,000mph and when discovered it was going 'only' 100,000mph. Space/Astronomy is a beautiful thing when it comes to relative perspective to us humans.

[autokad]

what upsets me most is that I dont think I'll be around by time we get the technology and funding to capture one of these things and study/learn from it

[laydn]

Could this be the first of a series of "objects" to come our way? Part of a large ejection of some sort?

[bdamm]

While considering the exotic, how about a test of our response time? We didn’t see it until it was past us.