<p>The aurora depicted in the artist's conception is of ultraviolet light.  It would not be seen with the naked eye.</p>

<p>"NASA's Hubble Space Telescope observed a pair of auroral belts encircling the Jovian moon Ganymede. <a href="http://hubblesite.org/image/3505/news_release/2015-09" rel="noreferrer">The belts were observed in ultraviolet light</a> by the Space Telescope Imaging Spectrograph and are colored blue in this illustration. They are overlaid on a visible-light image of Ganymede taken by NASA's Galileo orbiter. The locations of the glowing aurorae are determined by the moon's magnetic field, and therefore provide a probe of the moon's interior, where the magnetic field is generated. The amount of rocking of the magnetic field, caused by its interaction with Jupiter's own immense magnetosphere, provides evidence that the moon has a subsurface ocean of saline water."</p>

CC BY-SA 4.0
2020-01-16T10:41:54.490Z
There's a similar question with an answer that says the opposite: https://astronomy.stackexchange.com/a/34725/9809
user31389
CC BY-SA 4.0
2020-01-16T13:08:21.890Z
@user31389  That is a question I asked.  I had added the comment to my question, "'Follow-up observations will be difficult because the auroras were only visible in ultraviolet light,' https://www.astrobio.net/history/ganymedes-auroras-point-to-ocean-below-its-icy-surface-2/"
Bob516
CC BY-SA 4.0
2021-04-08T12:15:40.633Z
How ultraviolet is it? [You don't have to come from another planet to see ultraviolet light](https://www.theguardian.com/science/2002/may/30/medicalscience.research) :-)
uhoh
CC BY-SA 4.0
2019-05-14T15:51:02.387Z
2019-05-14T15:51:02.387Z
Bob516
<p>If one was orbiting in the Jovian system, as depicted in this artist conception,</p>

<p><a href="https://i.sstatic.net/2FufF.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/2FufF.jpg" alt="enter image description here"></a></p>

<p>could the aurora be seen unassisted? </p>

<p><a href="http://hubblesite.org/image/3501/news_release/2015-09" rel="nofollow noreferrer">Hubblesite-Illustration Credit: NASA, ESA, and G. Bacon (STScI)</a></p>

CC BY-SA 4.0
2019-01-07T01:44:44.723Z
Can you credit and add a link to the source of the image (unless of course you are the artist). I'm wondering if the artist is representing UV light as blue/violet here.
uhoh
CC BY-SA 4.0
2019-01-07T02:24:59.707Z
On the next page of the Hubblesite I did find, "The belts were observed in ultraviolet light by the Space Telescope Imaging Spectrograph and are colored blue in this illustration."
Bob516
CC BY-SA 4.0
2019-01-07T02:28:52.123Z
bingo! In that case you can consider writing an answer to your own question, and that is always okay in Stack Exchange. After a few days to see if other answers are also posted, it would be fine to accept your answer if you like as well. You can also ask a follow up question "Why is Ganymede's aurora only visible in ultraviolet while Earth's is bright green and red?"
uhoh
<hubble-telescope><naked-eye><aurora>
Could Ganymede's aurora be seen with the naked eye?
Bob516
# Could Ganymede's aurora be seen with the naked eye?

(Asked by: username_0 on 2019-01-06)

If one was orbiting in the Jovian system, as depicted in this artist conception,

[![enter image description here](https://i.sstatic.net/2FufF.jpg)](https://i.sstatic.net/2FufF.jpg)

could the aurora be seen unassisted?

[Hubblesite-Illustration Credit: NASA, ESA, and G. Bacon (STScI)](http://hubblesite.org/image/3501/news_release/2015-09)

**Tags:** hubble-telescope, naked-eye, aurora

> **Comments:**
> **username_1**: Can you credit and add a link to the source of the image (unless of course you are the artist). I'm wondering if the artist is representing UV light as blue/violet here.  
> **username_0**: On the next page of the Hubblesite I did find, "The belts were observed in ultraviolet light by the Space Telescope Imaging Spectrograph and are colored blue in this illustration."  
> **username_1**: bingo! In that case you can consider writing an answer to your own question, and that is always okay in Stack Exchange. After a few days to see if other answers are also posted, it would be fine to accept your answer if you like as well. You can also ask a follow up question "Why is Ganymede's aurora only visible in ultraviolet while Earth's is bright green and red?"  

---

## 1 answers

### Answer by username_0 on 2019-05-14. Score: 6 | Accepted answer

The aurora depicted in the artist's conception is of ultraviolet light. It would not be seen with the naked eye.

"NASA's Hubble Space Telescope observed a pair of auroral belts encircling the Jovian moon Ganymede. [The belts were observed in ultraviolet light](http://hubblesite.org/image/3505/news_release/2015-09) by the Space Telescope Imaging Spectrograph and are colored blue in this illustration. They are overlaid on a visible-light image of Ganymede taken by NASA's Galileo orbiter. The locations of the glowing aurorae are determined by the moon's magnetic field, and therefore provide a probe of the moon's interior, where the magnetic field is generated. The amount of rocking of the magnetic field, caused by its interaction with Jupiter's own immense magnetosphere, provides evidence that the moon has a subsurface ocean of saline water."

> **Comments:**
> **username_2**: There's a similar question with an answer that says the opposite: https://astronomy.stackexchange.com/a/34725/9809  
> **username_0**: @username_2  That is a question I asked.  I had added the comment to my question, "'Follow-up observations will be difficult because the auroras were only visible in ultraviolet light,' https://www.astrobio.net/history/ganymedes-auroras-point-to-ocean-below-its-icy-surface-2/"  
> **username_1**: How ultraviolet is it? [You don't have to come from another planet to see ultraviolet light](https://www.theguardian.com/science/2002/may/30/medicalscience.research) :-)  

---

