<p>Apart from Auroras, UV emissions can be used to study the exospheres of planets and large moons, as well as some of the atmospheric constituents. The exosphere is the outermost layer of planetary or planetary-moon atmospheres and its study can help understand the escape processes and evolution of these atmospheres. For example, The UV spectrometer on the Mariner 10 spacecraft discovered the exosphere of Mercury and that it contained Hydrogen and Helium (other elements were discovered later) The Mariner 9 discovered the steady escape of Hydrogen from Mars. The Ozone layer in the Earth's atmosphere is being studied extensively in UV as well.</p>

CC BY-SA 4.0
2024-06-05T09:20:23.623Z
2024-06-05T09:20:23.623Z
Netra Shanbag
<p>UV spectrum of planets mainly aids in the study of their atmospheres and magnetospheres. The spectrum <a href="https://link.springer.com/article/10.1007/s11214-014-0077-z" rel="nofollow noreferrer">includes</a>:</p>
<blockquote>
<ol>
<li><p>Strong resonance transitions of the most abundant atmospheric and exospheric elements, e.g., hydrogen, helium, and oxygen have emission
lines in the UV spectral range short of 1500 Å.</p>
</li>
<li><p>For solar planets, interactions among solar wind, the magnetospheres, the exospheres, ionospheres, and atmospheres give rise
to diagnostic UV emission on a global scale.</p>
</li>
<li><p>Many of the primary astrophysical interaction processes occur in the energy equivalent temperature from 10<sup>4</sup> to 10<sup>6</sup> Kelvin, producing
transitions in the UV.</p>
</li>
</ol>
</blockquote>

CC BY-SA 4.0
2024-06-04T07:18:34.057Z
2024-06-05T02:10:29.543Z
2024-06-05T02:10:29.543Z
Ritesh Singh
<p>I've never read any UV planetary research, but I imagine it tells the atmosphere gases because they'd fluoresce under UV. In theory, the frequencies emitted would tell what atoms re-emitted the photons.</p>
<p>You certainly see it at the poles, unless auroras are synchrotron radiation. I'm not an expert.</p>

CC BY-SA 4.0
2024-06-05T19:04:20.137Z
2024-06-05T19:04:20.137Z
Miss Understands
<p>Recently I was browsing through Ultraviolet images clicked by Cassini, Galileo and Hubble Space Telescope on OPUS and though they all seemed quite attractive, I couldn't quite figure out what all possible data can one obtain from UV images of planets-especially gas giants. One possibility is that of aurorae occurring at the poles. What else can we determine?
Likewise if we photograph comets and/or asteroids in UV spectrum, what all information, can it provide us?</p>

<asteroids><comets><planetary-science><gas-giants>
How can ultraviolet planetary images help us in research?
Dhruv Nayak
# How can ultraviolet planetary images help us in research?

(Asked by: username_0 on 2024-05-30)

Recently I was browsing through Ultraviolet images clicked by Cassini, Galileo and Hubble Space Telescope on OPUS and though they all seemed quite attractive, I couldn't quite figure out what all possible data can one obtain from UV images of planets-especially gas giants. One possibility is that of aurorae occurring at the poles. What else can we determine?
Likewise if we photograph comets and/or asteroids in UV spectrum, what all information, can it provide us?

**Tags:** asteroids, comets, planetary-science, gas-giants

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## 3 answers

### Answer by username_1 on 2024-06-05. Score: 3 | Accepted answer

Apart from Auroras, UV emissions can be used to study the exospheres of planets and large moons, as well as some of the atmospheric constituents. The exosphere is the outermost layer of planetary or planetary-moon atmospheres and its study can help understand the escape processes and evolution of these atmospheres. For example, The UV spectrometer on the Mariner 10 spacecraft discovered the exosphere of Mercury and that it contained Hydrogen and Helium (other elements were discovered later) The Mariner 9 discovered the steady escape of Hydrogen from Mars. The Ozone layer in the Earth's atmosphere is being studied extensively in UV as well.


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### Answer by username_2 on 2024-06-04. Score: 3

UV spectrum of planets mainly aids in the study of their atmospheres and magnetospheres. The spectrum [includes](https://link.springer.com/article/10.1007/s11214-014-0077-z):

> 1. Strong resonance transitions of the most abundant atmospheric and exospheric elements, e.g., hydrogen, helium, and oxygen have emission
>    lines in the UV spectral range short of 1500 Å.
> 2. For solar planets, interactions among solar wind, the magnetospheres, the exospheres, ionospheres, and atmospheres give rise
>    to diagnostic UV emission on a global scale.
> 3. Many of the primary astrophysical interaction processes occur in the energy equivalent temperature from 104 to 106 Kelvin, producing
>    transitions in the UV.


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### Answer by username_3 on 2024-06-05. Score: 2

I've never read any UV planetary research, but I imagine it tells the atmosphere gases because they'd fluoresce under UV. In theory, the frequencies emitted would tell what atoms re-emitted the photons.

You certainly see it at the poles, unless auroras are synchrotron radiation. I'm not an expert.


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