We recently celebrated the success of the Chandrayan-3 mission as the Vikram lander performed a soft landing on the lunar south pole. With the Pragyan rover now roving around, my X feed (previously Twitter) seems flush with illustrations of the mission and the images relayed back by the probes sent to the moon. I cannot help but notice that most photos are nearly black-and-white. The video of the rover rolling out is in color, but the surroundings are still mostly grey! So, I wondered if the moon's surface is just all those shades of grey or something is amiss.
While I could intuit that the spacecraft would typically want to minimize the amount of data to the minimum that could help retrieve and reconstruct it again, I wondered if things have changed since the first time humans landed on the moon. We've come a long way in how we compress and decompress data for transmission compared to 1969, right? Also, back when some astronauts were strutting around on the moon and taking pictures that didn't require direct transmission - the cameras would be coming back with the astronauts. Those images are in color, but the moon is still a little grey.
Well, the moon's surface is mostly dull - in shades of grey. This rocky gray comes from the dominance of Silicon, Iron, Oxygen, Magnesium, and a few other elements on the moon's surface. Most other planets are also similarly drab-looking with a palette based on the dominant mineral(s). Further scientists have a hypothesis (backed by some experimental evidence) that at the time of the moon's formation, the cooling magma formed the top white layer, and subsequent meteor strikes on it pulled up the darker magma layers. It is commonly agreed that most of the surface's dark and grey matter comes from volcanic activity.
What about the blue moon, blood moon, orange moon? The other colors of the moon - blue, red, yellow, orange - are mostly due to the composition of our earth's atmosphere. I don't know. Suddenly, all this makes me feel more grateful that we are here on earth to experience all this variety of color.