Exploring Space: Observing Galaxies 1.5 Million Light Years Away

  • Thread starter IllogicalDreamr
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In summary, The conversation is about the concept of observing objects in space and how they appear as they were in the past. The person is wondering if it is possible for life to have evolved in a galaxy that is 1.5 million light years away, since we would be seeing it 1.5 million years in the past. There could be changes happening in the galaxy currently that we would not be aware of until 1.5 million years later. Janus explains that at that distance, we would not be able to detect life and that changes in the galaxy may not be noticeable at our level of detail. The person finds it fascinating that 1.5 million years is a relatively short time for a galaxy.
  • #1
IllogicalDreamr
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This is my first post(Oh, second post. =P) here. I usually lurk the boards because I feel I don't know enough about the topics here to discuss anything.

This one thing has been bothering me.

I've read before that when we obverse things in space we are not seeing them as they are now, but as they were in the past.

So, say we observe a random galaxy that is 1.5 million light years away. We are seeing it 1.5 million years in the past, right? So if we were to go to that galaxy, it would look nothing like as we were observing it from Earth? Wouldn't it be possible that life could have evolved in that galaxy? We wouldn't be able tell since we're observing it in the past.

I'm not entirely sure if I'm perceiving this correctly or not. If someone could explain it to me I'd appreciate it alot.
 
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  • #2
As far as the galaxy itself goes, generally, they don't change very fast, so We really wouldn't notice much change, especially at the level of detail we can attain at that distance. Speaking of which, at that distance, we would not be able to detect life anyway, so we don't know if that galaxy even had life 1.5 million years ago, given the images we now have.

But yes, some changes could occur that would not be aware of for 1.5 million years. For example there could be a supernova in that galaxy today and we would have to wait 1.5 million years before we saw it.
 
  • #3
Janus said:
As far as the galaxy itself goes, generally, they don't change very fast, so We really wouldn't notice much change, especially at the level of detail we can attain at that distance. Speaking of which, at that distance, we would not be able to detect life anyway, so we don't know if that galaxy even had life 1.5 million years ago, given the images we now have.

But yes, some changes could occur that would not be aware of for 1.5 million years. For example there could be a supernova in that galaxy today and we would have to wait 1.5 million years before we saw it.

Thank you for answering, Janus.

I find it very interesting that 1.5 million years is really nothing to a galaxy. And that we would have to wait 1.5 million years to know if something even did happen in the galaxy. O_O
 

FAQ: Exploring Space: Observing Galaxies 1.5 Million Light Years Away

How can we observe galaxies 1.5 million light years away?

In order to observe galaxies 1.5 million light years away, we use powerful telescopes and advanced imaging techniques. These telescopes are equipped with large mirrors and advanced sensors that can detect light from distant galaxies. Additionally, we can also use space-based telescopes that are not affected by the Earth's atmosphere and can provide clearer images of these galaxies.

What is the significance of observing galaxies 1.5 million light years away?

By observing galaxies 1.5 million light years away, we can gain a better understanding of the universe and its evolution. These galaxies are considered to be relatively close to us in astronomical terms, and studying them can give us insights into the formation and structure of galaxies. It can also help us learn about the different stages of a galaxy's life and how it interacts with its environment.

How do we measure distances of galaxies 1.5 million light years away?

We use a variety of techniques to measure the distance of galaxies 1.5 million light years away. One method is called parallax, where we measure the apparent shift in the position of a nearby star against the background of distant galaxies. We can also use the properties of stars, such as their brightness and spectral type, to estimate the distance of a galaxy. Additionally, we can use the redshift of galaxies to determine their distance, which is a measure of how much their light has been stretched due to the expansion of the universe.

Can we see the galaxies 1.5 million light years away in real time?

No, we cannot see the galaxies 1.5 million light years away in real time. Since light travels at a finite speed, it takes 1.5 million years for the light from these galaxies to reach us. This means that we are seeing these galaxies as they were 1.5 million years ago, not as they are today. However, with the advancement of technology, we are able to observe these galaxies in more detail and with higher resolution than ever before.

What can we learn from observing galaxies 1.5 million light years away?

By observing galaxies 1.5 million light years away, we can learn about the structure, composition, and evolution of the universe. We can also study how galaxies interact with each other and their surrounding environment. Additionally, observing these galaxies can help us test theories and models about the formation and evolution of the universe. It can also give us clues about the presence of dark matter and dark energy, which are still mysteries in the field of astrophysics.

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