NASA has created a beautiful simulation of how Mars might have looked billions of years ago. It's a fascinating view that looks eerily like Earth. According to NASA:
Billions of years ago when the Red Planet was young, it appears to have had a thick atmosphere that was warm enough to support oceans of liquid water - a critical ingredient for life. The animation shows how the surface of Mars might have appeared during this ancient clement period, beginning with a flyover of a Martian lake. The artist's concept is based on evidence that Mars was once very different. Rapidly moving clouds suggest the passage of time, and the shift from a warm and wet to a cold and dry climate is shown as the animation progresses. The lakes dry up, while the atmosphere gradually transitions from Earthlike blue skies to the dusty pink and tan hues seen on Mars today.
So keep that in mind as you watch the video pan over an ancient Martian lake, fast forward through time, and send the skies shifting from blue to red. Because that familiar barren surface the video ends on may very well be a pick into Earth's own dry, dusty future. [NASA Goddard]