Interstellar space rock screams through Solar System Astronomers have spotted an object that they believe came from another star system. The 400-metre-wide object – dubbed A/2017 U1 – was first spotted on October 19 after it slingshotted around the Sun. Analysis of its trajectory suggests it passed beneath Earth's orbit by about 24 million kilometers on October 14. Whatever it …
Another article I read (phys.org) said " - appears to have originated from outside the solar system, coming from somewhere else in our galaxy."
Here's the link to the NASA article. Ah yes, as quoted by phys.org, "...coming from somewhere else in our galaxy."
There's a penalty for reading too quickly...
Planet looks useful, may need to re-start with mew terraforming package as 'current' inhabitants have made such a mess.
Recommend fresh start -- current surface humanoid surface dwellers not vital for regeneration --oh and the Dolphins say ''Hi' to everyone, took yer bloody time'
According to The State Of The Art, we already had a GCU come visit about forty years ago without anyone noticing, so I don't know why we'd expect to recognise one now ;)
... means that it was on a hyperbolic orbit. Mathematically, this means that it is not gravitationally bound to the Sun, and will escape from the Solar System in due course. The Voyager and Pioneer spacecraft are also on hyperbolic orbits, by design. None of these things came from outside the galaxy.
The Voyager and Pioneer spacecraft are also on hyperbolic orbits, by design. None of these things came from outside the galaxy.
Out of interest, I wonder what the eccentricity values are for Voyager and Pioneer? (just for the sake of comparison with this thing)
I'd expect something coming from interstellar space to swing wide around the sun. The story doesn't say how close it came, but judging by the handbrake turn it did that was practically a direct hit!
Very odd that the first interstellar object we saw made such a close pass. Or is it that the close pass makes it easier to detect?
We only spotted it after it passed the Sun, and the article states that astronomers are only counting on a few weeks to study it - after that it will be too dark.
This thing is not a comet, it's a rock.
To me that means that there are probably many more rocks like that flying around in the most awesome game of billiards ever invented, and we don't have a clue about where or how many.
There's likely all kinds of orbits for those things - but we won't see any of them if they stay beyond Jupiter's orbit.
As stars lose mass, their planets presumably have a tendency to wander off into inter-stellar space. So presumably there are quite a few Jupiter sized bodies floating around the galaxy. I seem to recall someone seriously claiming that our own solar system evolved with a fifth gas giant in a much closer orbit to the sun which was then expelled, resulting in the more stable planetary order we have today.
H G Wells did a short story on such an event called "the Star". It's travel through the solar system did not disturb us much, apart from minor re-arrangement of the continents and throwing the Moon into a much wider orbit. Nothing to worry about, really.
From the images, it passed very close to the Sun - deep within the orbit of Mercury. Statistically, given the size of the Universe, that looks really unlikely. If it was an alien spacecraft, it may have used the close passage for a gravity assist maneuver - keep into a mind we only saw it on its way out, and the incoming path is extrapolated. If it was just a space rock, either we were really lucky, or there are orders of magnitude more such objects passing through the Solar system, but somehow we failed to see any until now.
There are probably quite a few going by, but statistically they usually pass at some ungodly distance like Neptune's orbit or even much further (and far outside the ecliptic too!). This rock practically hit us! None of the other inner planets were even in the same solar hemisphere, just us sitting ducks.
Y'know, a 15 million kilometer pass could have easily been zero/zero/zero with (or, without?) a very slight delta-v change a few years ago.
Just sayin...
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> "...there is no up or down in space..."
Sure there is, but you only notice it when you oppose what down wants to do with you. It's still there tho, pulling you towards the strongest local down-hole, relentlessly. If you escape the earth down, the sun down still has you, and this rock may have got away from the sun down but it won't escape the galaxy down. And our galaxy won't escape that other galaxy.
Basically, going down is what everything does, sooner or later.
Is it good, bad, or indifferent that the dinosaurs died out? Will it be good, bad, or indifferent if humans die out? I'm with good/indifferent in both cases. If you like diversity, you probably don't like species to hang around too long or infest multiple planets.
OK, but did anyone actually hear it?
Hubble got a pretty good shot of the bridge. No sound, but guesses can be made.
Looks like Space Nazis being troubled by Antifa to me. I would have expected Moties.
Also, from Jimboinfocenter::
Average orbital speed 26 km/s (58,000 mph) (peaking at 87.8 km/s at perihelion)
I would have expected a bit more somehow.
@Destroy All Monsters :
"...I would have expect a bit more [speed] somehow."
That's 26 km/s at infinity. Look at it from the sun (really, the solar system barycenter) a few centuries back, and it would be barrelling toward you at 26.07 +/- 0.10 km/s. A few centuries from now, it'll be going away at the same speed. As it went by the Sun, it went much faster. Further details at (warning, I'm author of the linked page)
https://projectpluto.com/temp/2017u1.htm#speed .
Given we only noticed this one because it passed so close to the sun, one can assume there are many more of them zooming through our solar system all the time. We might regret the peaceful ol' times when NEOs and rogue comets were all we had to worry about...
Hard hats might become fashionable.
@aqk - no. See https://www.projectpluto.com/temp/2017u1.htm#alt_ideas . Yours is debunked idea #2. (If it's any consolation, some professional astronomers had the same thought at first.)
BTW, definitely this galaxy, at 26 km/s incoming speed. From anyplace else, we'd be talking hundreds of km/s (and probably wouldn't have noticed it).
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