Live data from Hacker News

The first known object to enter our solar system from deep space

cbc.ca

71–80 of 114 posts

Re: The first known object to enter our solar system from deep space

#71

Very interesting! So all known "stuff floating around in our solarsystem" like Hale-Bopp et al have been deemed originating from here? Or have that conclusion just been taken for granted? 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…

It’s apparently to do with the orbit - they identified this as extrasolar purely by the fact its orbit would be extremely unlikely to have arisen from our solar system’s protoplanetary disk.

[deleted]

Re: The first known object to enter our solar system from deep space

#72
post #13
post #4

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…

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 thro…

> 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/

Re: The first known object to enter our solar system from deep space

#73

Earlier quoted context omitted.

Co-author here. We obtained spectroscopic measurements of 'Oumuamua, and its surface closely matches D-type asteroids and comet nuclei, which are dark, reddish and organic-rich.

Of course an asteroid, hollowed out somewhat, makes for a good spaceship. Especially if you're trying to be covert. Perhaps someone has discovered warp drives (is gravitational wave detection the first step) and the Federation have sent a ship to observe us.

Gravitational wave detection is nowhere near the first step to any sort of warp drive. In fact it is looking the like the nail in the warp drive coffin. I, and no doubt many others here, was hoping the new detectors would be picking up all sorts of tiny wave sources buzzing around us, a civilization of warp drives just beyond our previous limits of observation. But no, no tiny warp signatures. We are still alone. If ET is in our local galaxy he isn't using warp drives, only reducing their possibility.

Re: The first known object to enter our solar system from deep space

#74

"This artist's concept shows [...]" 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?

Artist’s is fine (“artist his”), artists’s would be artists’. Depends on how many people worked on the art piece :)

For the record, the expansion "... his" is considered "folk etymology": a reanalysis from the Early Modern English period in the language's history. Notice for example how it doesn't make sense for feminine words: "Mary's house".

In fact, the possessive "'s" is a leftover from Old English, where the inflectional suffix "es" marked the genitive case.

Re: The first known object to enter our solar system from deep space

#75

Earlier quoted context omitted.

If you wanted to disguise a probe, it seems the ideal form would be a black body, not to disguise it as an asteroid, I would guess. Unless they're playing mind games. 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…

> 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. Ah, but it's a carrier for the small, stealthy probes!

And waterbears.

Re: The first known object to enter our solar system from deep space

#76
post #51
post #2

What a pity they did not call it Rama ;-) https://en.wikipedia.org/wiki/Rendezvous_with_Rama

Would be interesting if it changed course.

"interesting" is an understatement. We'd instantly have a new space/weapon race.

Re: The first known object to enter our solar system from deep space

#77

Earlier quoted context omitted.

For comparison, the Earth's radius is 0.00004 AU. This is like a mosquito passing your car at a closest distance of 2 miles.

~395 earth-moon distances away and 1/20th the size of the object that killed the dinosaurs

1/20th the size, but 4 time the speed. Assuming the density of the 2 objects were the same, and because energy is proportional to the square of speed, it would cary a similar amount of energy.

Re: The first known object to enter our solar system from deep space

#78

Earlier quoted context omitted.

0.16 AU, according to the paper.

For comparison, the Earth's radius is 0.00004 AU. This is like a mosquito passing your car at a closest distance of 2 miles.

...but I still have mosquitos hitting my windshield. Hopefully there are not many more objects like that asteroid inbound...

Re: The first known object to enter our solar system from deep space

#79
post #13

Earlier quoted context omitted.

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 thro…

> 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…

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

Re: The first known object to enter our solar system from deep space

#80
post #56
post #13

Earlier quoted context omitted.

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 thro…

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

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