April 25, 2024

We Asked a NASA Scientist: Are There Rainbows on Mars [Video]

A rainbow in the desert (in the world.).
Are there rainbows on Mars? There are an entire lot of other conditions on Mars that we have right here on Earth!

Thats a terrific question. There are water clouds in the thin atmosphere of Mars, so why not rainbows? You might have even seen an image from the Perseverance rover with an arc across the sky. That was not a rainbow; it was a lens flare. We saw that lens flare even in brilliantly lit laboratory images.

By NASA
January 23, 2022

In a rainbow, sunlight enters a spherical droplet, reflects off the back, and comes back towards you. Snow does not make rainbows since it has a complicated shape. You do not get liquid beads that can make rainbows; theres just not adequate water.
The beads are 20 times smaller sized across than a human hair, 10 times smaller sized than Earths cloud beads, and far smaller than rain. They would need to be more than 10 times larger to make a rainbow with a thousand times more water.
While there arent rainbows on Mars, there are lots of Earth-like weather phenomena. There are still clouds on Mars when the season is right, both water ice like we have on Earth and clouds of dry ice co2. And there are dust devils, dust storms and winds that blow the clouds and dust around. So, weather is still a huge part of what the rovers are looking at on Mars. However Im sorry to dissatisfy you. Mars has some Earth-like weather condition, but no rainbows.

There are water clouds in the thin atmosphere of Mars, so why not rainbows? You do not get liquid droplets that can make rainbows; theres simply not sufficient water.
While there arent rainbows on Mars, there are numerous Earth-like weather condition phenomena. Mars has some Earth-like weather, however no rainbows.