If we look from Earth with the naked eye at Mars, many may say that it appears to be a red color. After all, it is known as the “red planet”. Well, the truth is that Mars does not actually look red from down here on Earth. It appears as a brownish, tan color. Mars really is reflecting a lot of red spectrum light, and red, being a longer wavelength than blue, eats through the atmospheric distortion and is less scattered than the shorter wavelengths are. Therefore, a good deal of that red actually reaches our eyes on Earth, and the filtering effects of the atmosphere do not cancel the red entirely. After that red is filtered through our atmosphere, what color information that manages to fight it’s way through leaves Mars with the tan coloured planet we see from Earth.

Now, there are times when Mars can indeed appear red, or redder, to the naked eye from Earth. Depending on the atmospheric conditions and just where Mars lies in relation to the earth’s horizon when it is being viewed, those tan Martian colors we see on Earth can be amplified to appear far deeper than they actually are. After all, sometimes the Moon looks red from Earth, all depending upon the atmospheric “seeing” conditions!

SAMPLE

This known ability of the atmosphere to alter the color of celestial objects is something that is VERY important and is often overlooked by the public when considering the true naked eye color of Mars or other planets, as seen from Earth.

This is likewise the case for Jupiter, another common telescopic target. When talking about determining color of a celestial object through telescopic observations, remember that we are talking about naked-eye observations through the eyepiece of an unfiltered (or limited filtered) telescope system, with no frame-stacking, no color filters or color-channel shifting enhancements. Now, through a small unfiltered telescope, you are not going to see any true color characteristics if you look at Jupiter. You are going to see a high-albedo bright dot, depending on atmospheric seeing conditions, as well as some smaller dots that are Jupiter‘s largest Moons.

SAMPLE

Here is a great color telescopic shot of the limb of the Moon with Saturn beyond it. You can see that this is a color image, but Saturn’s color doesn’t exactly leap out at you, does it? Much of it’s color is not readily detectable without filters or enhancements to color.

SAMPLE

See much color in Saturn here? I don’t! This is Saturn at 250x magnification from Earth. SAMPLE

There are telescopic views of Jupiter from Earth for example where we can see a feature known as the “Great Red Spot”. Here is a Voyager image of the Great Red Spot

And here is a telescopic view from Earth of Jupiter, where you can see the Great Red Spot shows to be brown here. SAMPLE
The Great Red Spot is visible during last half of clip - but it is not red, it is tan, because the red of the spot has been atmospherically filtered and looks brown from Earth. The same goes for the deep browns of the stripes on Jupiter, that appear far less vibrant and more tan than they really are, after our atmosphere has filtered some of the color out.

Just to highlight how prevalent the use of modern technology is in celestial planet-gazing nowadays, here is an interesting example.

This is the “MarsWatch” website, where amateur astronomers around the world can submit their telescopic images of Mars. There are pages and pages of these on this site alone, and you can see that virtually all of these telescopic images have been “frame-stacked” and color-filtered by the astronomer who took them. Trying to find real “true” color images ofMars that have any detail at all that have not been filtered is VERY hard to do. All the big observatories typically filter, and just about every amateur with a telescope large enough and the gear to image the eyepiece stack their footage to create enhanced stills, and they use filters to help highlight surface colors.
Here is a “Mars Filter” for a telescope that many astronomers use for example, because it enhances the contrast of that planet’s browns (like sunglasses can!) All this alters the true color as seen from Earth by the naked eye!

Here is another example of a series of Jupiter images. Note the frame-stacking and coloring enhancements admitted to. SAMPLE

Jupiter again, notice the color correction this image went through. SAMPLE

Trying to find unstacked, unfiltered views of planets through telescopes is very hard, because they need filters to eat through the bright albedo and make out details. many in the public do not realize that the amateur telescope images they see on the internet are typically stacked and color corrected/filtered to make for the best detail, not for the most accurate color representation!