The Real Night Sky?

Question

Given the fact that light from the nearest star (excluding the Sun) is 4 light years old, what we see as a night sky is a mirage (or a peek into the past) dating back in some areas to billions of years ago.

What does the night sky look like right now; in realtime if such a thing is at all possible?

Answer 1

Real-time night sky viewing as you described is not possible, since light travels at a precise speed. As you said, the light from the stars is anything from a few years to several billion years old.

If it were possible to see the stars in real time, then light would have to travel at an infinitely large speed. Since that is not the case, we can only see the "snapshots" of the stars that are as old as their distance in light-years. (e.g. if a star is 100 LY away, the light you see today was emitted 100 years ago).

Answer 2

The vast majority of stars that are visible without telescopes are within a thousand light-years or two from us. This means we are seeing them as they were at most 2000 years ago. Since the typical star lasts billions of years, the night sky would appear almost exactly the same if we saw it as it is rather than the mixed time version we actually see. The only exceptions would be stars that are red giants that have undergone supernovae. It is possible that one or two have done so, but even this is rather unlikely.

When you use a telescope, there are two populations of objects you might be interested in. The first are in our galaxy and are either stars or gasseous nebula. Again, the life span of the stars is in the billions of years range. The nebula have much shorter lifespans. The farthest you can get in our galaxy is only abut 100,000 lightyears, so again, it doesn't make too much difference except that some of the planetary nebula would have expanded a bit. The second population consists of other galaxies.

For amateur telescopes, the galaxies visible are usually within a couple hundred million lightyears and so would not be very different than what we see, except that the spirals would have rotated and the specific positions would have changed some (but not that much because the distances are great enough that it wouldn't be a huge effect). It is only in the professional scopes that any major changes would be noticed.

Answer 3

When you see the stars in the night, you are actually seeing the light from the star that was emitted from there even thousands of years back respectively with reference to their distance from the observer. The nearest star is the Proxima Centuri and is 4.6 light years away from the earth. That is the light starting from that star will take 4.6 years to reach earth. The light travels approximately 300000000 metres per second and the distance travelled by light in one year is called a light year.

When you look at the sky in the night you are observing the image or view of different stars at different ages simultaneously. The image that you see cannot be considered as real as some of those stars, even might have got dead or extinct.

Answer 4

If that was possible, the sky would look pretty much the same. After all, the sky looked the same in biblical times as it does now, and we are just now seeing the stars that are thousands of light years away as they really were back then. It takes more than a mere few thousand years for the stars to change noticeably.

Answer 5

The night sky 'looks' exactly as we see it. Looking is dependent on light. What I guess you mean is "what would the night sky look like if there were no time delay before the light reached our eyes and we could see the current placement of the stars in the sky?" Unfortunately this is not possible, however it is probably possible to calculate the current position of the brighter stars based on their relative position and distance from earth. We would also need to know in what direction each of them was moving when the light left them tens, hundreds or millions of years ago. Based on their tragectory and speed and distance from us we could work out where they would be right now (provided of course they they haven't changed velocity during that time).

Answer 6

It's hard to tell without knowing the future of every star in the sky. Red supergiants like Betelgeuse or Antares may be changed dramatically but I'd say what we can see with the naked eye would be pretty much the same. Most of what we see is well under 2000 ly and that's not long compared to the life cycle of a star.

Answer 7

easily, all you spot contained in the evening sky is amazingly a lot as you spot it. because the distances are so vast and and the existence of maximum stars see you later, any alterations from our attitude are minute. that's authentic that some very distant products ought to no longer nevertheless exist, yet that fairly in ordinary words applies to such issues as Hubble pictures of a procedures deeper area than you could locate with the unaided eye. All even the most important telescope can do is improve the mild accomplishing it, yet what it may do is keep those photons till an photo is outfitted up giving us pictures of the Universe billions of years in the past. remember, on a cosmic scale, each and everything takes position slowly, and movements of heavenly bodies can frequently be envisioned with a intense degree of precision. regardless of the indisputable fact that, some issues at the instantaneous are not really common. that is substantially commonly used operating example, that the acceptance Betelgeuse in Orion is on the point of crumple and transforming into an excellent nova. regardless of the indisputable fact that, on the point of in cosmological words ought to surely be yet another million years, so do not carry your breath.

Answer 8

To the naked eye very much the same... a few stars might go missing or suddenly show up in new places or get brighter or dimmer as their proper motion moves them along... but not much time would have gone by for what we see. Andromeda would be a little brighter I believe.

For distant viewing with telescopes we might have dimmer skies (certainly in the IR) and probably wouldn't have quasars.

Answer 9

In reality, you can take a box, have someone put something in it, and have them close it, and you observe it, not knowing whats in it, and sleep after thinking about what COULD be in it. Your dreams should reveal what's in the box.

Answer 10

It's daytime here