<p>Millimeter and sub-mm observations (110-300 GHz = 2.7-1.0 mm) are sensitive to the thermal emission and provide a brightness temperature of airless bodies like the Moon or asteroids. The radio emission is from just below the surface/skin of the body (down to <span class="math-container">$\sim10\lambda$</span> so ~1 cm in this case) and so is also sensitive to the thermal inertia and conductivity of the surface and regolith. A paper discussing sub-mm observations of the Moon (which is freely available) is <a href="https://cab.inta-csic.es/users/jrpardo/paper43.pdf" rel="noreferrer">Pardo et al. 2005</a>.</p>

<p>A major issue with observation in the mm/sub-mm is atmospheric absorption due to precipitable water vapour (PWV) as seen in the plot below which shows the atmospheric transmission in the mm/sub-mm at the summit of Mauna Kea (~4100 meters):
<a href="https://i.sstatic.net/omdDN.png" rel="noreferrer"><img src="https://i.sstatic.net/omdDN.png" alt="Atmospheric transmission in the sub-mm at Mauna Kea"></a></p>

<p>Note that the worst case shown (in red) with 5mm PWV is already a very dry atmosphere that is rarely found even at other high mountain sites; sea level sites could easily have 50+mm of PWV. This could make these type of measurements very challenging.</p>

CC BY-SA 4.0
2019-09-20T12:41:55.837Z
2019-09-20T12:41:55.837Z
astrosnapper
<p>I would like to test a telescope with a Moon observation.
It is a low spectrometer-imager at 110-300 GHz with a resolution of 4 arcmin@150 GHz.</p>

<p>Is there any scientific target that concerns the Moon with such an observation?</p>

<the-moon><interferometry><spectrometry>
mm-wavelengths Moon map, scientific case
Raizen
# mm-wavelengths Moon map, scientific case

(Asked by: username_0 on 2019-09-20)

I would like to test a telescope with a Moon observation.
It is a low spectrometer-imager at 110-300 GHz with a resolution of 4 arcmin@150 GHz.

Is there any scientific target that concerns the Moon with such an observation?

**Tags:** the-moon, interferometry, spectrometry


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## 1 answers

### Answer by username_1 on 2019-09-20. Score: 6

Millimeter and sub-mm observations (110-300 GHz = 2.7-1.0 mm) are sensitive to the thermal emission and provide a brightness temperature of airless bodies like the Moon or asteroids. The radio emission is from just below the surface/skin of the body (down to $\sim10\lambda$ so ~1 cm in this case) and so is also sensitive to the thermal inertia and conductivity of the surface and regolith. A paper discussing sub-mm observations of the Moon (which is freely available) is [Pardo et al. 2005](https://cab.inta-csic.es/users/jrpardo/paper43.pdf).

A major issue with observation in the mm/sub-mm is atmospheric absorption due to precipitable water vapour (PWV) as seen in the plot below which shows the atmospheric transmission in the mm/sub-mm at the summit of Mauna Kea (~4100 meters):
[![Atmospheric transmission in the sub-mm at Mauna Kea](https://i.sstatic.net/omdDN.png)](https://i.sstatic.net/omdDN.png)

Note that the worst case shown (in red) with 5mm PWV is already a very dry atmosphere that is rarely found even at other high mountain sites; sea level sites could easily have 50+mm of PWV. This could make these type of measurements very challenging.


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