The Curiosity Rover and its tracks appear in an image taken by NASA's Mars Reconnaissance Orbiter (MRO), from its orbit over 400 kilometers above the surface of Mars. MRO has been orbiting Mars since 2006, monitoring Mars' surface and weather. The image below was taken by MRO's HiRISE camera, which boasts the largest reflecting telescope placed on board any deep space mission. This gives HiRISE the ability to make out features of less than a meter across on the surface.
This isn't the first time HiRISE has taken a picture of Curiosity. You may recall seeing a picture of Curiosity and its parachute descending down to the Martian surface; that was taken by HiRISE as well. Pictures like this one strike me as particularly remarkable, because we can literally see the influence humanity has had on the surface of another planet with an instrument that we placed in orbit around said planet. If the "pale blue dot" picture makes us feel small within the expanse of space, this should make us feel the weight of our impact within it.
I highly recommend checking out the HiRISE image catalog for more extraordinary pictures of Mars.