Sometimes scientists use enhanced-color images to reveal subtle variations on the surface of Mars. This view from our Mars Odyssey orbiter highlights details in clouds hovering over canyons in the Margaritifer Terra region in December. More from Odyssey: science.nasa.gov/mission/odyssey/ | NASA Mars

The @MarsCuriosity's first colour photograph of a sunset was captured in 2015. To everyone's amazement, the sunset appeared blue! While the rest of the sky is yellow to orange during dusk, the part of the sky near the Sun appears blue in colour. | The Weather Channel