<p>This is a really interesting question to many and it deserves an answer post even if folks close it.</p>
<p>In Wikipedia's <a href="http://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects" rel="noreferrer">List of the most distant astronomical objects</a> we can see that the <a href="https://en.wikipedia.org/wiki/Distance_measures_(cosmology)#Light-travel_distance" rel="noreferrer">distances that the light travelled to get to us</a> are all around 13 giga light years, and it's no coincidence that the age of the universe is also about 13 billion years.</p>
<p>We can't really call that the actual distance to the object because the size of the universe is changing and the size of the <a href="https://en.wikipedia.org/wiki/Observable_universe" rel="noreferrer">observable universe</a> is changing as well.</p>
<p>So while we like to say we are seeing really really far away, we should really think about it as seeing really really far back in time, because on the scale of the universe the speed of light is actually incredibly slow :-)</p>
<p>No matter how big of a telescope we build with unbelievable light gathering power, we'll never be able to see &quot;farther&quot; than a certain distance. There's a currently unknowably larger universe out there whose light and gravity has not and probably never will reach us</p>
<p>It's almost certainly based on current understanding, but that's subject to change of course ;-)</p>

CC BY-SA 4.0
2020-11-17T06:53:24.920Z
+1 there is no "farthest" in universe.
Nilay Ghosh
CC BY-SA 4.0
2020-11-17T07:40:05.557Z
In the spirit of quoting rather than linking it is maybe worth saying that the Wikipedia page you link gives a galaxy called GN-z11 as the most distant object actually imaged. It has its own wikipedia page https://en.wikipedia.org/wiki/GN-z11
Steve Linton
CC BY-SA 4.0
2020-11-17T07:49:15.243Z
@SteveLinton *Thanks!* I'm amenable to you adding that as a new answer or just going ahead and adding it to this one. Your answers are always *great* so the former is better in my opinion, but I also always welcome helpful edits to my posts.
uhoh
CC BY-SA 4.0
2020-11-17T03:26:33.657Z
2020-11-17T03:26:33.657Z
uhoh
<p>Supplementary to @uhoh's answer:</p>
<p>According to <a href="https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects" rel="nofollow noreferrer">the wikipedia page</a> he links, the most distant imaged object is a galaxy classed <a href="https://en.wikipedia.org/wiki/GN-z11" rel="nofollow noreferrer">GN-z11</a>.</p>
<blockquote>
<p>GN-z11 is a high-redshift galaxy found in the constellation Ursa Major. The discovery was published in a paper headed by P.A. Oesch and Gabriel Brammer (Cosmic Dawn Center). GN-z11 is currently the oldest and most distant known galaxy in the observable universe. GN-z11 has a spectroscopic redshift of z = 11.09, which corresponds to a proper distance of approximately 32 billion light-years (9.8 billion parsecs). The object's name is derived from its location in the GOODS-North field of galaxies and its high cosmological redshift number (GN + z11). GN-z11 is observed as it existed 13.4 billion years ago, just 400 million years after the Big Bang; as a result, GN-z11's distance is sometimes inappropriately reported as 13.4 billion light-years, its light-travel distance measurement.</p>
</blockquote>
<p>Beyond that distance (or, as it usually more helpful to think of it, further back in time) as @RobJeffries observes, we detect the cosmic microwave background and we can &quot;explore&quot; its exact spectrum and distribution around the sky, but we can't yet detect any specific objects beyond GN-z11.</p>

CC BY-SA 4.0
2020-11-17T16:22:57.713Z
Well, there aren't any objects in the material that emitted the CMB, just atoms, and perhaps the occasional small molecule.
PM 2Ring
CC BY-SA 4.0
2020-11-17T09:00:59.577Z
2020-11-17T16:35:37.867Z
2020-11-17T16:35:37.867Z
Steve Linton
<p>Distance in astronomy is equivalent to looking back in time, because of the finite speed of light.</p>
<p>If it's an object you're interested in, then <a href="https://astronomy.stackexchange.com/questions/496/which-galaxy-is-receding-from-the-milky-way-the-fastest-what-is-known-of-the-me">Which galaxy is receding from the Milky Way the fastest? What is known of the mechanism behind its recession?</a> covers it. There are various high redshift objects around <span class="math-container">$z=11$</span> which are being seen a few hundred million years after the big bang and whose light took more than 13 billion years to reach us.</p>
<p>However, direct exploration by telescopes takes us back to the cosmic microwave background, formed 400,000 years after the big bang. The light from this has been travelling for 13.7 billion years.</p>
<p>If we want to see further, the CMB provides an impenetrable fog from which no more distant electromagnetic waves can emerge. However, there are opportunities to study the cosmic neutrino and gravitational  backgrounds from earlier (and more distant, though not by much) epochs.</p>
<p>Arguably we have &quot;explored&quot; some of these most distant regions by using telescopes to investigate the &quot;primordial&quot; chemical abundances of helium, deuterium and lithium, which tell us about conditions in the first seconds to minutes after the big bang.</p>
<p>If one accepts this indirect exploration, then the fact we observe a matter filled universe is exploring the conditions less than <span class="math-container">$10^{-12}$</span>s after the big bang.</p>

CC BY-SA 4.0
2020-11-17T08:34:40.900Z
2020-11-17T08:34:40.900Z
ProfRob
<p>By using powerful telescopes on land and space, what's the farthest point humans have explored or viewed?</p>

CC BY-SA 4.0
2020-11-16T16:52:48.693Z
Does this answer your question? https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects
planetmaker
CC BY-SA 4.0
2020-11-16T21:53:39.660Z
The CMB is yet more far away, although it is not viewed by telescopes.
peterh
CC BY-SA 4.0
2020-11-17T01:30:22.293Z
Can you add some more details?
WarpPrime
CC BY-SA 4.0
2020-11-17T03:27:32.413Z
@fasterthanlight sometimes a new user asking their first question on a challenging topic like this simply can't add further details. Instead, a short answer can help put things into perspective.
uhoh
CC BY-SA 4.0
2020-11-17T06:59:18.367Z
@planetmaker there is no process by which a Stack Exchange question can be closed as duplicate of a Wikipedia article. The whole idea here is to cite sources within answers. "Does this answer your question?" mimics the message that close-as-duplicate voting generates, so we should try use other words if possible, and avoid confusing rhetorical questions especially immediately under the first question asked by a new user.
uhoh
CC BY-SA 4.0
2020-11-17T08:21:14.547Z
Does this answer your question? [Which galaxy is receding from the Milky Way the fastest? What is known of the mechanism behind its recession?](https://astronomy.stackexchange.com/questions/496/which-galaxy-is-receding-from-the-milky-way-the-fastest-what-is-known-of-the-me)
ProfRob
CC BY-SA 4.0
2020-11-17T11:04:29.293Z
Some links: [1](https://www.space.com/18502-farthest-galaxy-discovery-hubble-photos.html), [2](https://www.nasa.gov/feature/goddard/2018/hubble-uncovers-the-farthest-star-ever-seen), [3](https://imagine.gsfc.nasa.gov/features/cosmic/farthest_info.html).
Nilay Ghosh
<telescope><distances>
What's the farthest point humans have explored?
Stan Melling
# What's the farthest point humans have explored?

(Asked by: username_0 on 2020-11-16)

By using powerful telescopes on land and space, what's the farthest point humans have explored or viewed?

**Tags:** telescope, distances
> **Comments:**
> **username_1**: Does this answer your question? https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects  
> **username_2**: The CMB is yet more far away, although it is not viewed by telescopes.  
> **username_3**: Can you add some more details?  
> **username_4**: @fasterthanlight sometimes a new user asking their first question on a challenging topic like this simply can't add further details. Instead, a short answer can help put things into perspective.  
> **username_4**: @planetmaker there is no process by which a Stack Exchange question can be closed as duplicate of a Wikipedia article. The whole idea here is to cite sources within answers. "Does this answer your question?" mimics the message that close-as-duplicate voting generates, so we should try use other words if possible, and avoid confusing rhetorical questions especially immediately under the first question asked by a new user.  
> **username_5**: Does this answer your question? [Which galaxy is receding from the Milky Way the fastest? What is known of the mechanism behind its recession?](https://astronomy.stackexchange.com/questions/496/which-galaxy-is-receding-from-the-milky-way-the-fastest-what-is-known-of-the-me)  
> **username_6**: Some links: [1](https://www.space.com/18502-farthest-galaxy-discovery-hubble-photos.html), [2](https://www.nasa.gov/feature/goddard/2018/hubble-uncovers-the-farthest-star-ever-seen), [3](https://imagine.gsfc.nasa.gov/features/cosmic/farthest_info.html).  

---

## 3 answers

### Answer by username_4 on 2020-11-17. Score: 5

This is a really interesting question to many and it deserves an answer post even if folks close it.

In Wikipedia's [List of the most distant astronomical objects](http://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects) we can see that the [distances that the light travelled to get to us](https://en.wikipedia.org/wiki/Distance_measures_(cosmology)#Light-travel_distance) are all around 13 giga light years, and it's no coincidence that the age of the universe is also about 13 billion years.

We can't really call that the actual distance to the object because the size of the universe is changing and the size of the [observable universe](https://en.wikipedia.org/wiki/Observable_universe) is changing as well.

So while we like to say we are seeing really really far away, we should really think about it as seeing really really far back in time, because on the scale of the universe the speed of light is actually incredibly slow :-)

No matter how big of a telescope we build with unbelievable light gathering power, we'll never be able to see "farther" than a certain distance. There's a currently unknowably larger universe out there whose light and gravity has not and probably never will reach us

It's almost certainly based on current understanding, but that's subject to change of course ;-)

> **Comments:**
> **username_6**: +1 there is no "farthest" in universe.  
> **username_7**: In the spirit of quoting rather than linking it is maybe worth saying that the Wikipedia page you link gives a galaxy called GN-z11 as the most distant object actually imaged. It has its own wikipedia page https://en.wikipedia.org/wiki/GN-z11  
> **username_4**: @SteveLinton *Thanks!* I'm amenable to you adding that as a new answer or just going ahead and adding it to this one. Your answers are always *great* so the former is better in my opinion, but I also always welcome helpful edits to my posts.  

---

### Answer by username_7 on 2020-11-17. Score: 3

Supplementary to @uhoh's answer:

According to [the wikipedia page](https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects) he links, the most distant imaged object is a galaxy classed [GN-z11](https://en.wikipedia.org/wiki/GN-z11).

> GN-z11 is a high-redshift galaxy found in the constellation Ursa Major. The discovery was published in a paper headed by P.A. Oesch and Gabriel Brammer (Cosmic Dawn Center). GN-z11 is currently the oldest and most distant known galaxy in the observable universe. GN-z11 has a spectroscopic redshift of z = 11.09, which corresponds to a proper distance of approximately 32 billion light-years (9.8 billion parsecs). The object's name is derived from its location in the GOODS-North field of galaxies and its high cosmological redshift number (GN + z11). GN-z11 is observed as it existed 13.4 billion years ago, just 400 million years after the Big Bang; as a result, GN-z11's distance is sometimes inappropriately reported as 13.4 billion light-years, its light-travel distance measurement.

Beyond that distance (or, as it usually more helpful to think of it, further back in time) as @RobJeffries observes, we detect the cosmic microwave background and we can "explore" its exact spectrum and distribution around the sky, but we can't yet detect any specific objects beyond GN-z11.

> **Comments:**
> **username_8**: Well, there aren't any objects in the material that emitted the CMB, just atoms, and perhaps the occasional small molecule.  

---

### Answer by username_5 on 2020-11-17. Score: 2

Distance in astronomy is equivalent to looking back in time, because of the finite speed of light.

If it's an object you're interested in, then [Which galaxy is receding from the Milky Way the fastest? What is known of the mechanism behind its recession?](https://astronomy.stackexchange.com/questions/496/which-galaxy-is-receding-from-the-milky-way-the-fastest-what-is-known-of-the-me) covers it. There are various high redshift objects around $z=11$ which are being seen a few hundred million years after the big bang and whose light took more than 13 billion years to reach us.

However, direct exploration by telescopes takes us back to the cosmic microwave background, formed 400,000 years after the big bang. The light from this has been travelling for 13.7 billion years.

If we want to see further, the CMB provides an impenetrable fog from which no more distant electromagnetic waves can emerge. However, there are opportunities to study the cosmic neutrino and gravitational backgrounds from earlier (and more distant, though not by much) epochs.

Arguably we have "explored" some of these most distant regions by using telescopes to investigate the "primordial" chemical abundances of helium, deuterium and lithium, which tell us about conditions in the first seconds to minutes after the big bang.

If one accepts this indirect exploration, then the fact we observe a matter filled universe is exploring the conditions less than $10^{-12}$s after the big bang.


---

