<p>Yes. A t<a href="http://www.planetary-astronomy-and-imaging.com/en/image-surface-venus/" rel="nofollow noreferrer">hermal image from the surface can be detected</a>, even by amateurs.</p>

<p>The ground is heated to about 700K, and thermal emission at a wavelength of 1 micron is just about observable by skilled amateurs, with the right equipment. <a href="http://www.danielegasparri.com/venus_nightside_gasparri_.pdf" rel="nofollow noreferrer">Mountains, which are cooler by about 30K, can be seen at this wavelength</a></p>

<p>From orbit, more details can be seen. <a href="http://www.planetary.org/multimedia/space-images/venus/akatsuki-sees-venus-surface.html" rel="nofollow noreferrer">Akatsuki used the 1 micron band to observe the surface in 2015</a></p>

<p>At other wavelengths, cloud patterns are revealed. <a href="https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA00112" rel="nofollow noreferrer">Galileo took images at 2.3 microns during its flyby</a>. They show sulphuric acid clouds at 50km above the surface (10km below the visible cloud layer) and at about 270K, with gaps exposing the lower atmosphere, glowing at 500K. </p>

CC BY-SA 3.0
2017-04-23T06:52:45.730Z
2017-04-23T06:52:45.730Z
James K
<p><a href="https://astronomy.stackexchange.com/a/20817/7982">@JamesK's answer</a> is excellent. I just want to add another, more recent observation, with photos.</p>
<blockquote>
<p>In the case of Venus, does any of it's 800 degree surface temperature generated IR make it through it's atmosphere...</p>
</blockquote>
<p>From Space SE's <a href="https://space.stackexchange.com/q/58230/12102"></a> there are images of Venus at night (that's the side where they flyby happened) and at a modeled 735 K <em>average</em> temperature there was significant contrast from different surface features at different temperatures. The camera's bandpass was centered on very near infrared, but contained wavelengths shorter than 750 nm which they felt could be barely visible:</p>
<blockquote>
<p>The image below shows an image of Venus taken by Parker Solar Probe during a gravitational assist flyby on the left, and a topographical representation of the same surface on the right, with high altitudes shown as dark and low altitudes as bright shades, the idea being that the lowlands are hotter and so glow more brightly due to thermal radiation.</p>
<p>The modeled surface temperature of the night side here is 735 Kelvin.</p>
<p>While much of the light captured by the camera through its circa ~800 nm long wavelength cutoff can be called &quot;near infrared&quot; the authors estimate about 1/3 of the signal detected is below 750 nm, thus the <em>first in visible light</em> headlines.</p>
<p><a href="https://i.sstatic.net/M1sEU.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/M1sEU.jpg" alt="Figure 1. (a) Wide-Field Imager for Parker Solar Probe-I (WISPR-I) image of the nightside of Venus from Venus gravity assist (VGA) 3, showing thermal emission from the surface on the disk and O2 nightglow emission at the limb." /></a></p>
<blockquote>
<p>Figure 1</p>
<p>(a) Wide-Field Imager for Parker Solar Probe-I (WISPR-I) image of the nightside of Venus from Venus gravity assist (VGA) 3, showing thermal emission from the surface on the disk and O2 nightglow emission at the limb. Black to white represents 0 DN s−1 to 40 DN s−1 with the scale saturated at 40 DN s−1. The image is contaminated by numerous roughly horizontal dust streaks, from material ablating off the Parker Solar Probe heat shield. (b) Topographical map from Magellan, using an inverse black and white scale to match the WISPR image, with bright regions being low elevation and dark regions being high elevation. (c) WISPR-I and -O images of Venus from VGA4. The same part of the Venusian surface is observed as in (a). Red numbers in all panels mark common features for ease of reference. A movie of the VGA4 images is available in the online article.</p>
</blockquote>
<p>source: Wood et al. 2022 <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL096302" rel="nofollow noreferrer">Parker Solar Probe Imaging of the Night Side of Venus</a></p>
</blockquote>

CC BY-SA 4.0
2024-06-16T00:10:50.310Z
2024-06-16T00:10:50.310Z
uhoh
<p>This <a href="https://earthscience.stackexchange.com/questions/10158/which-physical-parameters-can-we-actually-measure-to-confirm-the-existence-of-th">question</a> got me thinking about this.   </p>

<p>I know that we measure the Earth's surface temperature by satellite (perhaps somewhat inaccurately, but it's done all the same).   Using Venus as an example, can we see see evidence of Venus' 800 degree surface from space or is Venus' temperature deduced more by modeling and the Russian ship that landed there.   </p>

<p>All things with heat give off a thermal signature and that signature isn't a single wavelength but a range of wavelength.   I assume, by measuring the overall color emitted and/or the peak wavelength, it's a fairly straight forward calculation to work out the temperature.</p>

<p>But when you have an atmosphere, and this is the main part of of my question.   I assume, an atmosphere is to some degree transparent, so you'd be seeing in a sense, heat through a medium and inside as well as on the upper surface.  But the heat you see diminishes depending on how opaque/transparent that atmosphere is to the specific wavelength.</p>

<p>Are there any good ballpark estimates to how thick (or how dense or pressurized), we can see temperature signatures through an atmosphere?     In the case of Venus, does any of it's 800 degree surface temperature generated IR make it through it's atmosphere, where it would be observable by spacecraft, giving a good measurement of it's surface temperature, or was it's surface temperature deduced by different types of models and that mistreated Soviet spacecraft that didn't last long once it had landed.</p>

<p>I imagine some atmospheric gases are more transparent than others.</p>

<p>Just to clarify - a specific "yes/no we can detect IR from Venus' surface" and a more general answer as to how far we can see heat through an atmosphere, are both fine.   </p>

CC BY-SA 3.0
2017-04-21T14:03:31.320Z
This is rather broad, since "IR camera" could mean anything from about 800 nm to 50 microns.  Further,  atmospheric transmission depends on the composition of said atmosphere.  Venus, Mars, and Terra have rather different compositions :-) .
Carl Witthoft
<planetary-atmosphere>
Can IR sensitive cameras read signals from Venus's surface emissions?
userLTK
# Can IR sensitive cameras read signals from Venus's surface emissions?

(Asked by: username_0 on 2017-04-20)

This [question](https://earthscience.stackexchange.com/questions/10158/which-physical-parameters-can-we-actually-measure-to-confirm-the-existence-of-th) got me thinking about this.

I know that we measure the Earth's surface temperature by satellite (perhaps somewhat inaccurately, but it's done all the same). Using Venus as an example, can we see see evidence of Venus' 800 degree surface from space or is Venus' temperature deduced more by modeling and the Russian ship that landed there.

All things with heat give off a thermal signature and that signature isn't a single wavelength but a range of wavelength. I assume, by measuring the overall color emitted and/or the peak wavelength, it's a fairly straight forward calculation to work out the temperature.

But when you have an atmosphere, and this is the main part of of my question. I assume, an atmosphere is to some degree transparent, so you'd be seeing in a sense, heat through a medium and inside as well as on the upper surface. But the heat you see diminishes depending on how opaque/transparent that atmosphere is to the specific wavelength.

Are there any good ballpark estimates to how thick (or how dense or pressurized), we can see temperature signatures through an atmosphere? In the case of Venus, does any of it's 800 degree surface temperature generated IR make it through it's atmosphere, where it would be observable by spacecraft, giving a good measurement of it's surface temperature, or was it's surface temperature deduced by different types of models and that mistreated Soviet spacecraft that didn't last long once it had landed.

I imagine some atmospheric gases are more transparent than others.

Just to clarify - a specific "yes/no we can detect IR from Venus' surface" and a more general answer as to how far we can see heat through an atmosphere, are both fine.

**Tags:** planetary-atmosphere

> **Comments:**
> **username_1**: This is rather broad, since "IR camera" could mean anything from about 800 nm to 50 microns.  Further,  atmospheric transmission depends on the composition of said atmosphere.  Venus, Mars, and Terra have rather different compositions :-) .  

---

## 2 answers

### Answer by username_2 on 2017-04-23. Score: 4

Yes. A t[hermal image from the surface can be detected](http://www.planetary-astronomy-and-imaging.com/en/image-surface-venus/), even by amateurs.

The ground is heated to about 700K, and thermal emission at a wavelength of 1 micron is just about observable by skilled amateurs, with the right equipment. [Mountains, which are cooler by about 30K, can be seen at this wavelength](http://www.danielegasparri.com/venus_nightside_gasparri_.pdf)

From orbit, more details can be seen. [Akatsuki used the 1 micron band to observe the surface in 2015](http://www.planetary.org/multimedia/space-images/venus/akatsuki-sees-venus-surface.html)

At other wavelengths, cloud patterns are revealed. [Galileo took images at 2.3 microns during its flyby](https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA00112). They show sulphuric acid clouds at 50km above the surface (10km below the visible cloud layer) and at about 270K, with gaps exposing the lower atmosphere, glowing at 500K.


---

### Answer by username_3 on 2024-06-16. Score: 1

[@JamesK's answer](https://astronomy.stackexchange.com/a/20817/7982) is excellent. I just want to add another, more recent observation, with photos.

> In the case of Venus, does any of it's 800 degree surface temperature generated IR make it through it's atmosphere...

From Space SE's  there are images of Venus at night (that's the side where they flyby happened) and at a modeled 735 K *average* temperature there was significant contrast from different surface features at different temperatures. The camera's bandpass was centered on very near infrared, but contained wavelengths shorter than 750 nm which they felt could be barely visible:

> The image below shows an image of Venus taken by Parker Solar Probe during a gravitational assist flyby on the left, and a topographical representation of the same surface on the right, with high altitudes shown as dark and low altitudes as bright shades, the idea being that the lowlands are hotter and so glow more brightly due to thermal radiation.
>
> The modeled surface temperature of the night side here is 735 Kelvin.
>
> While much of the light captured by the camera through its circa ~800 nm long wavelength cutoff can be called "near infrared" the authors estimate about 1/3 of the signal detected is below 750 nm, thus the *first in visible light* headlines.
>
> [![Figure 1. (a) Wide-Field Imager for Parker Solar Probe-I (WISPR-I) image of the nightside of Venus from Venus gravity assist (VGA) 3, showing thermal emission from the surface on the disk and O2 nightglow emission at the limb.](https://i.sstatic.net/M1sEU.jpg)](https://i.sstatic.net/M1sEU.jpg)
>
> > Figure 1
> >
> > (a) Wide-Field Imager for Parker Solar Probe-I (WISPR-I) image of the nightside of Venus from Venus gravity assist (VGA) 3, showing thermal emission from the surface on the disk and O2 nightglow emission at the limb. Black to white represents 0 DN s−1 to 40 DN s−1 with the scale saturated at 40 DN s−1. The image is contaminated by numerous roughly horizontal dust streaks, from material ablating off the Parker Solar Probe heat shield. (b) Topographical map from Magellan, using an inverse black and white scale to match the WISPR image, with bright regions being low elevation and dark regions being high elevation. (c) WISPR-I and -O images of Venus from VGA4. The same part of the Venusian surface is observed as in (a). Red numbers in all panels mark common features for ease of reference. A movie of the VGA4 images is available in the online article.
>
> source: Wood et al. 2022 [Parker Solar Probe Imaging of the Night Side of Venus](https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL096302)


---

