The second-smallest planet in the Solar System after Mercury, and the fourth planet from the Sun, discovering Mars was always a challenge for NASA to assess if there is habitability potential on it.

Mars is often referred to as the "Red Planet", because the reddish iron oxide prevalent on its surface gives it a reddish appearance that is distinctive among the astronomical bodies visible to the naked eye.

“You'd think Mars would be easier to understand. Like Earth, Mars has polar ice caps and clouds in its atmosphere, seasonal weather patterns, volcanoes, canyons and other recognizable features. However, conditions on Mars vary wildly from what we know on our own planet,” NASA said.

NASA had revealed around 2,500 in August, September and October for Mars. Here are some of them:

Photo: NASA's Mars Reconnaissance Orbiter observes many slopes in the middle latitudes of Mars showing icy flows or glaciers.

Photo: This enhanced color image from NASA's Mars Reconnaissance Orbiter shows the surface of a lobate debris apron in the Deuteronilus Mensae region of Mars, on the boundary between the Northern plains and Southern lowlands.

Photo: The layered sedimentary deposits inside the giant canyons of Mars have puzzled scientists for decades.

Photo:This false-color image demonstrates how use of special filters available on the Curiosity Mars rover's Mast Camera (Mastcam) can reveal the presence of certain minerals in target rocks. T