It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
originally posted by: eriktheawful
It's simple really:
Light travels at 299 792 km/s.
The Andromeda Galaxy is approaching our galaxy at 110 km/s.
So the light from Andromeda is going 2725 times faster than the galaxy itself is actually moving.
We measure it's distance based upon what we see (the light). The Andromeda Galaxy is at about 2.5 million light years away, so indeed, the light we are seeing is from where it was 2.5 million years ago.
So yes, it's actually closer than what we are seeing, because it is approaching us.
But how much closer?
We can calculate that. 1 lightyear is 9,460,730,472,580 km. Multiply that by 2.5 million:
That is how far away it was, 2.5 million years ago. But, because we know it's coming towards our galaxy at 110 km/s, we can figure that out too.
It's velocity is 3,468,960,000 km per year. Multiply that by 2.5 million:
8,672,400,000,000,000 km is how far it has traveled towards us in that 2.5 million years.
Now, subtract that number, from how many kilometers there are in 2.5 million light years:
23,651,826,181,450,000,000 - 8,672,400,000,000,000 = 23,643,153,781,450,000,000 km.
Now, divide the answer by the amount of kilometers in a light year:
23,643,153,781,450,000,000 / 9,460,730,472,580 = 2,499,083.32 lightyears.
So, even though it's had 2.5 million years to approach us, at only 110 km/s, it's still well over 2.4 million lightyears away.
It certainly would not look too much bigger to our eyes or telescopes!
originally posted by: Bedlam
originally posted by: KROandSOTV
What i am asking is,At this point in time NOW how many light years is it from our galaxy it cant be 2.5million light years away or is it.
That depends on whether it's moving toward us or away.
predicted to happen four billion years from now. It is likely the sun will be flung into a new region of our galaxy, but our Earth and solar system are in no danger of being destroyed.
Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy