<p>It appears the <strong>Earth's <a href="http://en.wikipedia.org/wiki/Magnetosphere#Magnetotail" rel="nofollow noreferrer">magnetotail</a></strong>, which is a part of its <strong><a href="http://en.wikipedia.org/wiki/Magnetosphere" rel="nofollow noreferrer">magnetosphere</a></strong>, is on the Earth's nightside; lengthwise exceeds 6,300,000 kilometers (3,900,000 miles); and is the furthest known observable feature of Earth.</p>

<p>I am unable to explain why is it commonly not included in the "spheres" of Earth Science.</p>

<p><img src="https://i.sstatic.net/CwcSD.jpg" alt="Diagram of Earth&#39;s magnetosphere, indicating direction of solar wind and highlighting the bow shock, magnetosheath, magnetopause, polar cusp, plasmasphere, plasma mantle, magnetotail lobes, plasma sheet, and neutral point."></p>

<p><strong>Note:</strong> <em>The gravitational pull of Earth in theory spans the known Universe, though it's unlikely to have any observable affect, unlike the Earth's magnetotail.</em> </p>

CC BY-SA 3.0
2014-04-30T20:15:44.727Z
2014-04-30T20:50:48.943Z
2014-04-30T20:50:48.943Z
blunders
<p>Guessing that the Earth's magnetic field is the furthest observable Earth Science related phenomenon from Earth itself, though not completely sure. </p>

CC BY-SA 3.0
2014-04-30T20:03:02.203Z
I think http://en.wikipedia.org/wiki/Triton_(moon) would be sad that you didn't think of it as part of Earth Science.
Neo
CC BY-SA 3.0
2014-04-30T20:05:22.310Z
You've crossed into a rather different scientific discipline. The Earth's magnetotail is of much greater interest to planetary science (a subdivision of astrophysics) than it is to the earth sciences.
David Hammen
CC BY-SA 3.0
2014-04-30T20:20:32.943Z
@DavidHammen: Interesting, so you're saying Earth Science is only concerned with what impacts Earth, and does not include what Earth impacts, right? If so, please cite an authoritative source. Thanks!
blunders
CC BY-SA 3.0
2014-04-30T20:27:07.360Z
@DavidHammen, I disagree with your assessment that Planetary Science is only a subdivision of astrophysics, when in fact, it is one of the biggest attractions at AGU. Furthermore, high impact journals also agree: EPSL (Earth and Planetary Sciences) lumps them together. Finally, most studies of Earth's magnetic field come from Earth Science departments.
Neo
CC BY-SA 3.0
2014-04-30T20:27:51.917Z
@Neo: Unable to find any reasoning behind your reference to [Triton](http://en.wikipedia.org/wiki/Triton_%28moon%29), which is the largest moon of the planet Neptune, and appears to be 4.549 billion kilometers (2.827 billion miles; 4.216 light hours) from Earth. Please explain your comment and cite an authoritative source. Thanks!
blunders
CC BY-SA 3.0
2014-04-30T20:35:22.027Z
@blunders I was merely pointing out that Triton is very far away, observable, and is studied by Earth Sciences. For example, there are icy satellite "tectonists" who use methods developed in earth sciences on these moons (or other way around). An example of that is Francis Nimmo, who has done many studies in this field.
Neo
CC BY-SA 3.0
2014-04-30T20:38:28.130Z
@blunders (and Neo): I never said that planetary science is only a subdivision of astrophysics. There is no clearcut boundary between the sciences. Look at fluid dynamics. You'll see papers from physicists, chemists, oceanographers, biologists and other life scientists, aerospace engineers. The boundaries are blurred at best. That said, do meteorologists and climatologists care about the Earth's magnetotail extending beyond the Moon? Not really. They have more than enough problems dealing with the impacts of a butterfly in Brazil flapping its wings.
David Hammen
CC BY-SA 3.0
2014-04-30T20:45:22.127Z
@Neo: I see, thanks for the explanation. Seems as though you're saying that any comparable source of observable phenomenon that is able to be correlated with Earth-based phenomenon is Earth Science. Is that correct? If so, guess I'd have to agree, since otherwise you'd have to discount the knowledge learned as not being part of Earth Science, which makes no sense. Is Triton the furthest away example you're able to cite real Earth Science based research on? If so, please think about posting that as an answer. Thanks!
blunders
CC BY-SA 3.0
2014-04-30T20:57:09.060Z
@blunders yes, that is exactly what I am saying. Though I don't know if triton is the furthest, just the furthest I could immediately think of.
Neo
CC BY-SA 3.0
2014-05-01T16:20:27.177Z
This question begs the question "What is Earth Science?"  *That* is a question for meta, not here.
Richard
CC BY-SA 3.0
2014-05-01T17:24:43.253Z
@Richard: If you don't feel a given answer is Earth Science related that your choice, but the question is not about what Earth Science is; on an unrelated note, [thanks for starting the ES.SE proposal on Area51 two years ago](http://area51.stackexchange.com/proposals/36296/earth-science).
blunders
CC BY-SA 3.0
2014-05-01T17:35:54.683Z
@blunders The question is very directly asking for an extent or inclusion list for "Earth Science".  In point: *"if Earth's magnetic field is part of Earth Science,* [snip] *why is it commonly not included in the "spheres" of Earth Science?"*  Even the title question is, essentially, "how far does Earth Science extend?"  I think this is asking pretty directly to delineate what constitutes "Earth Science".  That's why I believe this belongs on meta.
Richard
CC BY-SA 3.0
2014-05-01T17:37:01.973Z
@blunders And, as a side note, *thank you* for joining!  It's the community that makes the site, not me.
Richard
CC BY-SA 3.0
2014-05-01T17:43:42.360Z
@Richard: Yes, I know it's about the community, not you... :-) ...but as you know, proposals just don't magically appear either.
blunders
CC BY-SA 3.0
2014-05-01T17:44:34.083Z
@Richard: This is not a list question, since there is only one right answer at a given time. Also, there is no requirement that the answer state correct forever, nor is there any requirement that questions ask only questions that remain correct over time. As for the "inclusion" issue, I'll remove it, since it in my opinion is unlikely to get an answer; in fact, I removed almost all the text to keep it simple.
blunders
<geomagnetism><moon>
What is the furthest observable phenomenon from Earth that is Earth Science?
blunders
# What is the furthest observable phenomenon from Earth that is Earth Science?

(Asked by: username_0 on 2014-04-30)

Guessing that the Earth's magnetic field is the furthest observable Earth Science related phenomenon from Earth itself, though not completely sure.

**Tags:** geomagnetism, moon

> **Comments:**
> **username_1**: I think http://en.wikipedia.org/wiki/Triton_(moon) would be sad that you didn't think of it as part of Earth Science.  
> **username_2**: You've crossed into a rather different scientific discipline. The Earth's magnetotail is of much greater interest to planetary science (a subdivision of astrophysics) than it is to the earth sciences.  
> **username_0**: @username_2: Interesting, so you're saying Earth Science is only concerned with what impacts Earth, and does not include what Earth impacts, right? If so, please cite an authoritative source. Thanks!  
> **username_1**: @username_2, I disagree with your assessment that Planetary Science is only a subdivision of astrophysics, when in fact, it is one of the biggest attractions at AGU. Furthermore, high impact journals also agree: EPSL (Earth and Planetary Sciences) lumps them together. Finally, most studies of Earth's magnetic field come from Earth Science departments.  
> **username_0**: @username_1: Unable to find any reasoning behind your reference to [Triton](http://en.wikipedia.org/wiki/Triton_%28moon%29), which is the largest moon of the planet Neptune, and appears to be 4.549 billion kilometers (2.827 billion miles; 4.216 light hours) from Earth. Please explain your comment and cite an authoritative source. Thanks!  
> **username_1**: @username_0 I was merely pointing out that Triton is very far away, observable, and is studied by Earth Sciences. For example, there are icy satellite "tectonists" who use methods developed in earth sciences on these moons (or other way around). An example of that is Francis Nimmo, who has done many studies in this field.  
> **username_2**: @username_0 (and Neo): I never said that planetary science is only a subdivision of astrophysics. There is no clearcut boundary between the sciences. Look at fluid dynamics. You'll see papers from physicists, chemists, oceanographers, biologists and other life scientists, aerospace engineers. The boundaries are blurred at best. That said, do meteorologists and climatologists care about the Earth's magnetotail extending beyond the Moon? Not really. They have more than enough problems dealing with the impacts of a butterfly in Brazil flapping its wings.  
> **username_0**: @username_1: I see, thanks for the explanation. Seems as though you're saying that any comparable source of observable phenomenon that is able to be correlated with Earth-based phenomenon is Earth Science. Is that correct? If so, guess I'd have to agree, since otherwise you'd have to discount the knowledge learned as not being part of Earth Science, which makes no sense. Is Triton the furthest away example you're able to cite real Earth Science based research on? If so, please think about posting that as an answer. Thanks!  
> **username_1**: @username_0 yes, that is exactly what I am saying. Though I don't know if triton is the furthest, just the furthest I could immediately think of.  
> **username_3**: This question begs the question "What is Earth Science?"  *That* is a question for meta, not here.  
> **username_0**: @username_3: If you don't feel a given answer is Earth Science related that your choice, but the question is not about what Earth Science is; on an unrelated note, [thanks for starting the ES.SE proposal on Area51 two years ago](http://area51.stackexchange.com/proposals/36296/earth-science).  
> **username_3**: @username_0 The question is very directly asking for an extent or inclusion list for "Earth Science".  In point: *"if Earth's magnetic field is part of Earth Science,* [snip] *why is it commonly not included in the "spheres" of Earth Science?"*  Even the title question is, essentially, "how far does Earth Science extend?"  I think this is asking pretty directly to delineate what constitutes "Earth Science".  That's why I believe this belongs on meta.  
> **username_3**: @username_0 And, as a side note, *thank you* for joining!  It's the community that makes the site, not me.  
> **username_0**: @username_3: Yes, I know it's about the community, not you... :-) ...but as you know, proposals just don't magically appear either.  
> **username_0**: @username_3: This is not a list question, since there is only one right answer at a given time. Also, there is no requirement that the answer state correct forever, nor is there any requirement that questions ask only questions that remain correct over time. As for the "inclusion" issue, I'll remove it, since it in my opinion is unlikely to get an answer; in fact, I removed almost all the text to keep it simple.  

---

## 1 answers

### Answer by username_0 on 2014-04-30. Score: 3 | Accepted answer

It appears the **Earth's [magnetotail](http://en.wikipedia.org/wiki/Magnetosphere#Magnetotail)**, which is a part of its **[magnetosphere](http://en.wikipedia.org/wiki/Magnetosphere)**, is on the Earth's nightside; lengthwise exceeds 6,300,000 kilometers (3,900,000 miles); and is the furthest known observable feature of Earth.

I am unable to explain why is it commonly not included in the "spheres" of Earth Science.

![Diagram of Earth's magnetosphere, indicating direction of solar wind and highlighting the bow shock, magnetosheath, magnetopause, polar cusp, plasmasphere, plasma mantle, magnetotail lobes, plasma sheet, and neutral point.](https://i.sstatic.net/CwcSD.jpg)

**Note:** *The gravitational pull of Earth in theory spans the known Universe, though it's unlikely to have any observable affect, unlike the Earth's magnetotail.*


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