For the fourth year in a row, iridescent clouds of frozen CO2 are lighting the Martian sky. The clouds appear in the same place, at the same time of year.

That color has led to them being nicknamed "mother-of-pearl" clouds. While Mars' atmosphere is 95% carbon dioxide, few of its clouds are at a high enough atmosphere and low enough temperature to ...

Known as "nacreous clouds" or "mother-of-pearl clouds," these clouds are a very rare phenomenon. Captured on Jan. 12, when the sun was located just below the horizon, the unforgettable appearance ...

Amid the flowing clouds are red and green hues. Though these high fliers also can be observed at the edge of space above Earth, there are distinct differences between Mars' mother-of-pearl clouds ...

"Sometimes these clouds even create a rainbow of colors, producing iridescent, or 'mother-of-pearl,' clouds," NASA said. The colors in the new images are faint and were created as the clouds ...

It shows colourful "mother-of-pearl" clouds, so-called because of the pretty pastel colours you can see in them. They're made up of frozen carbon dioxide, which you may know as dry ice ...

These noctilucent clouds, consisting of water-ice and carbon-dioxide ice, appear higher in the atmosphere and are especially noted for their 'mother-of-pearl' iridescence. Curiosity's ongoing ...

"Sometimes these clouds even create a rainbow of colors, producing iridescent, or 'mother-of-pearl,' clouds," NASA said. The colors in the new images are faint and were created as the clouds scattered ...