3
$\begingroup$

If the solar system were suddenly placed in the middle of a large void... would everything still function as normal?

Would we even notice any difference here on Earth apart from the night sky?

...and speaking of the night sky, would that even look much different to how it is already? I imagine just less colourful and and more sparse, but seeing whole galaxies instead of individual stars?

Or would moving the solar system into a void just mean the end of the world as we know it?

$\endgroup$
  • $\begingroup$ Hungry void, or just an ordinary 1 particle per couple per couple cubic meter void? I don't think anyone's even considered the possibility of matter destroying voids yet. We would not do well there, if they exist. $\endgroup$ – Wayfaring Stranger Jul 19 '19 at 1:17
1
$\begingroup$

The solar system could continue to exist outside a galaxy, and apart from a lack of stars in the night sky, I see no reason why anything much would change. It would be very unlikely to form there, even if some chance provided a sufficiently dense gas cloud. The cloud would be made up of almost nothing except hydrogen and helium (since there would not have been previous generations of stars to enrich it) so (a) it would be hard for a star as small as the Sun to form and (b) there would certainly be no solid planets.

A void is just a region with a relatively low density of galaxies. Relatively low does not mean zero, so the solar system could continue to exist, or even form, in a galaxy in a void with no problems, but in most parts of most voids it could not form.

$\endgroup$
3
$\begingroup$

If you took away the Milky Way except for the Solar system (but kept the MW's satellite galaxies), the "naked eye" night sky would feature the Andromeda Galaxy, 2.5 million light-years away, the Large Magellanic Cloud (LMC), 160,000 light-years away and the Small Magellanic Cloud (SMC), 200,000 light years away.

$\endgroup$
2
$\begingroup$

Actually the further away the Solar System is from anything else the better for life. There would be less radiation and fewer mass extinction events from supernovas. We would not see galaxies instead of stars; their brightness would not increase. In fact if we were located in one of the great intergalactic voids the night sky would be completely dark to the naked eye.

$\endgroup$
  • $\begingroup$ to be honest it was actually intergalactic voids I was referring to, but going by the answers received it appears I wasn't very clear with wording my question! — nonetheless would the sky really appear completely dark in such a case? I heard that you would still see lots of tiny points of light, but instead of them being stars they would be entire galaxies $\endgroup$ – Pel Jul 13 '19 at 11:29
  • 2
    $\begingroup$ Yes, completely dark. Only 8 galaxies are visible to the naked eye and half of them only under ideal circumstances. In the middle of an intergalactic void the closest galaxy would be orders of magnitude too far away to be visible. In fact merely moving the solar system outside of the local group would have the same effect. $\endgroup$ – KevinRethwisch Jul 13 '19 at 14:04
  • $\begingroup$ One of the biggest is the Bootes void, which was discovered in 1981; it is 250 million light-years across, and until recently only two dozen galaxies had been found in it. That's a very void void. "If the Milky Way had been in the center of the Bootes void," says astronomer Greg Aldering of the University of Minnesota, "we wouldn't have known there were other galaxies until the 1960s." -- web.archive.org/web/20071119011039/http://findarticles.com/p/… $\endgroup$ – KevinRethwisch Aug 12 '19 at 5:13
1
$\begingroup$

As far as we can tell, the solar system is in such a void already. The region of space outside of the solar system is thought to be pretty sparse but that is hard to tell. We know the nearest star is Alpha Centauri which is over 4 light-years away. If the solar system was moved to an even less dense area if would not be noticeable. There may be planetary bodies nearby to our solar system but we currently have no way of finding these.

$\endgroup$
  • $\begingroup$ You're undoubtedly right, but the answer would be the same: No noticeable impact other than a boring night sky. Maybe fewer new comets, since they are hypothesized as being partly caused by disturbances in the f/o/r/c/e/ Oort Cloud due to other stars. $\endgroup$ – Mark Olson Jul 10 '19 at 0:45
  • $\begingroup$ What if the void means: in a non-expanding universe, no galaxy to turn with. Would really everything be the same? $\endgroup$ – Koray Jul 10 '19 at 9:15
  • $\begingroup$ i had no reason to think Void meant no expansion... $\endgroup$ – jmh Jul 10 '19 at 19:44
  • 1
    $\begingroup$ Could you provide a reference for "As far as we can tell, the solar system is in such a void already"? Our solar system is part of the Local Group, within the Virgo Cluster, within the Lanakea supercluster. You can't be in a supercluster and also be in a void: they are mutually exclusive. $\endgroup$ – Chappo Hasn't Forgotten Monica Jul 13 '19 at 4:38
  • 1
    $\begingroup$ @Koray Universe expansion is very weak, so it only affects things on the very large scale. There's no expansion inside a solar system, a galaxy, or even inside a cluster of galaxies, the gravitational attraction inside those systems overwhelms the expansion. So you only see expansion between galaxy clusters, and at larger scales. $\endgroup$ – PM 2Ring Jul 17 '19 at 13:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.