What is the true color of Venus?

[Helio]

There are all kinds of images on-line, but most use UV filters, etc. In the past, a lot of images were false color ones using those early radar maps of the surface.

I'm asking if there are any near true-color images of Venus, even if only partial disk images. So, like other planets (e.g. Neptune), I'm asking how Venus looks, which would be of its outer atmosphere.

About 10 years ago, I never could find any though the outer planets had true, or natural, color images. So are there some now?

 

[YetAnotherBob]

Use a telescope. The true color of Venus is white on white. In visible light, it's a near featureless slightly fuzzy white. You're looking at cloud tops from a large distance away after all. The actual visible light photos are featureless white.

And yes, there are many on line.

Th UV Filters are used so there is some contrast in what you see. Otherwise, there is nothing to look at, just a featureless white disk.

 

[rod]

FYI, early morning 12-July-2020 I enjoyed telescope views of Venus at 40x using my 90-mm refractor along with comet NEOWISE. Here is a note from my stargazing log. "At 0420 EDT, I could easily see NEOWISE with unaided eyes, nice tail. Using the Telrad made positioning the comet in the eyepiece FOV quick, especially a naked eye comet with tail. Other stars in Auriga visible in the telescope eyepiece view along with the comet. I enjoyed views of brilliant crescent shape Venus with Aldebaran and some other Hyades stars visible in the eyepiece at 40x. The color contrast of Venus and Aldebaran very good. Venus brilliant white crescent shape near 36” angular size compared to the red giant Aldebaran color orange-red, like Mars. The telescope views this morning of NEOWISE, Venus and Aldebaran, would make some great photos."

Sometimes I use a polarizing filter or blue filter to enhance Venus appearance and reduce the brightness and glare, at times some cloud banding areas become slightly visible too. Comparing Venus color with Aldebaran with no filters using my telescope, I think was a good color check. Venus and Aldebaran fit in the same FOV at 40x that morning.

 

[Helio]

Yet these are appearances as seen below our color-altering atmosphere. Venus is often high enough where our atmosphere's yellowing effect may not matter enough to make a difference, but are there any true color or "natural color" images from equipped satellites, as was true for some sent to Jupiter and other outer planets?

Venus may actually be a pure white-looking object if seen from space. If the atmosphere reflects light evenly (Mie Scattering) as our water vapor clouds do, then it makes sense that it would also be white, though perhaps there are some color differences due to certain compositional changes from storms, etc.

Alternatively, a spectral comparison of Venus, with extinction adjustments if needed, and the Sun, would be all that is necessary if they are identical.

 

[Helio]

However, as seen beneath our color-altering environment, these are appearances.
Venus is always high enough that the yellowing effect of our atmosphere does not matter enough to make a difference,

That's likely but Venus gets no higher than 46 degrees, and that's a 40% increase in atmosphere (AM1.39). That could make a difference if Venus has, say, a slight yellow tint before entering our atmosphere. An AM0 SED would be handy so we can compare it to the Sun's. Snow, for instance, has a reflectance spectrum of up to about 98% of the Sun's . Depth and flake size are somewhat important.

Venus is bright white as it is covered with sunlight reflecting and scattering clouds.

Well, if the clouds are water vapor, like our clouds, then MIE scattering would indeed produce a white Venus. But we know they aren't water vapor. So would the composition of the upper clouds still reflect in a neutral manner, similar to our clouds? I doubt it, but it may take more than a trivial amount of absorption to give us a shade of yellow, or other color.

Since Venus is so bright, we have to take Color Constancy into account, which says that our eyes will color shift to cause Venus to be more white than it might be under different contrast circumstances. A car's headlight (tungsten), for instance, will have an obvious yellow tint to it during the day, but most of the yellow disappears when we see it at night. Our eye uses sunlight as the white source, causing the lower temperature light to become more yellow.

 

[William Ashley]

There are all kinds of images on-line, but most use UV filters, etc. In the past, a lot of images were false color ones using those early radar maps of the surface.

I'm asking if there are any near true-color images of Venus, even if only partial disk images. So, like other planets (e.g. Neptune), I'm asking how Venus looks, which would be of its outer atmosphere.

About 10 years ago, I never could find any though the outer planets had true, or natural, color images. So are there some now?

What do you mean? True color. First off color is a cultural concept, but with that said are you talking the atmosphere. Yellowish brown (maybe orangey). The surface is not too colorful.

CO2 and sulfur gas are mostly colourless but get a little "greyed". Chlorine is a bit yellowish. Neon is a little orange. The color is basically cloud cover, https://www.sciencedirect.com/topics/earth-and-planetary-sciences/venus-clouds . The sulfiric acid can create a whitish blue cover. https://physics.stackexchange.com/questions/205448/how-do-white-neon-lights-work https://www.physicscentral.com/expl...xtending from the,out of the upper atmosphere.

 

[Helio]

What do you mean? True color. First off color is a cultural concept, but with that said are you talking the atmosphere.

By "true color", I mean that if we could look at it from space, preferably close enough to see surface features, and see it within the normal photopic vision level, so that excessive brightness doesn't distort our color vision, as with the Sun.

Yellowish brown (maybe orangey). The surface is not too colorful.

Agreed, if it were a more saturated color then we would all see it. If it is slightly yellowish, then seeing it from below our atmosphere would enhance it due to normal atmospheric scattering that makes object shift their color to the red end of the spectrum.

But I still can't rule out a slight hint of color here and there. Ideally, we could look at SEDs taken along the disk to see surface features (color variations), if any. Perhaps some have because it would easy to do.

CO2 and sulfur gas are mostly colourless but get a little "greyed". Chlorine is a bit yellowish. Neon is a little orange. The color is basically cloud cover, https://www.sciencedirect.com/topics/earth-and-planetary-sciences/venus-clouds . The sulfiric acid can create a whitish blue cover. https://physics.stackexchange.com/questions/205448/how-do-white-neon-lights-work https://www.physicscentral.com/explore/plus/electric-wind-venus.cfm#:~:text=In a surprising discovery, scientists,the upper atmosphere of Venus.&text=The rays extending from the,out of the upper atmosphere.

Thanks for the links. I think it's reasonable to say the Mie scattering dominates the color and makes it appear white, but just how pure is that white? We see many near "true color" or "natural" color images for almost all the planets and even Pluto, so why not Venus? Admittedly, it's not that interesting compared to Jupiter, but it's such an easy target.

 

[Helio]

Hi
Venus may actually be a pure white-looking object if seen from space. If the atmosphere reflects light evenly as our water vapor clouds do, then it makes sense that it would also be white, though perhaps there are some color differences due to certain compositional changes from storms, etc.

Agreed, but its seems odd to me we have so little evidence (images) of its true color. It's strange that the two brightest objects (except our orbiting moon) have been so froth with ambiguity in their true color.

 

[serhiy1635]

There are all kinds of images on-line, but most use UV filters, etc. In the past, a lot of images were false color ones using those early radar maps of the surface.

I'm asking if there are any near true-color images of Venus, even if only partial disk images. So, like other planets (e.g. Neptune), I'm asking how Venus looks, which would be of its outer atmosphere.

About 10 years ago, I never could find any though the outer planets had true, or natural, color images. So are there some now?

I found some pictures of the surface of the Venus . I am not sure wether these photo are without filters. But I assume they might be quite real.

real photos of venus - Google Suche

 

[Helio]

I found some pictures of the surface of the Venus . I am not sure wether these photo are without filters. But I assume they might be quite real.

real photos of venus - Google Suche

Thanks, but those are radar images, IIRC. The radar allowed them to see through the dense cloud. They used false coloring to help distinguish surface features.

It's a safe bet that the majority of images of Venus, including in textbooks, is still of such false coloring radar images. There isn't anything wrong with using them -- I would versus just a white, or mainly white, disk -- but it would be nice to see a true color image now and then, if one is found. I say the same thing regarding the Sun, and I am fine with making it yellow or orange as well. Once a false color image, however, becomes ubiquitous and without any mention that it's a false color image, then people will assume the false color is the true color.

 

[Helio]

Here is some artwork that I did several years ago for a website article (3rd part of 3) on the Sun's true color. [I chose to make it light-hearted but I went too zany with my verbiage, no doubt, and the host later asked me to do a formal presentation instead, but that would only be two paragraphs to prove the Sun "ain't yeller", so I've yet to do it]. I don't think I've seen others do this yet, surprisingly. It was an early attempt to show a reasonably "true color" view of the solar system. The biggest problem was, ironically, in getting an image of the planet closest to us, Venus. The one here is what I found which comes from processing done by Ricardo Nunes.

They are presented to scale, except for the Sun. The asteroid belt divides the scales used.

 

[vincenzosassone]

We see many near "true color" or "natural" color images for almost all the planets and even Pluto, so why not Venus?

Venus, because of its thick atmosphere, in this field is comparable to the gaseose giant. We have the "near true color" of Pluto (and Mercury too) because they don't have the atmosphere, thus we directly see the soil's color. About other terrestrial planet we can say that they have a weak atmosphere, just for this reason they don't have any changement in their "real color". Whereas Venus, like the giant planet, isn't able to show us the surface's soil because of its atmosphere. In fact we have the same problems with other giant planet as Saturn... I hope that i didn't wrong any grammar rule and that my knowledge was true, I'm new here and in this field too.

 

[Helio]

Venus, because of its thick atmosphere, in this field is comparable to the gaseose giant. We have the "near true color" of Pluto (and Mercury too) because they don't have the atmosphere, thus we directly see the soil's color. About other terrestrial planet we can say that they have a weak atmosphere, just for this reason they don't have any changement in their "real color". Whereas Venus, like the giant planet, isn't able to show us the surface's soil because of its atmosphere. In fact we have the same problems with other giant planet as Saturn... I hope that i didn't wrong any grammar rule and that my knowledge was true, I'm new here and in this field too.

Welcome aboard! My interest, however, is simply how Venus looks if we are above our atmosphere and we look at it with our eyes (safely and without filter issues). I'm fairly sure it isn't too bright such that our color cones are a bit overwhelmed, which causes skewing of the colors - almost always toward white for any near-blackbody emissions.

I suspect there could be some light streaking colors like caramel or yellow, though perhaps seasons or storms change these. It may, however, be simply white regardless of region or time. It's just as interesting to me that I'm even asking this question given that it's not some remotely visible object.