Mars rover Curiosity, which is now roughly half way to its final destination, has taken a brief pause to look up at the sunsetting sky and take a photo of Earth. In the photo above, Earth is roughly 99 million miles away -- and if you squint, you can also see the Moon. According to NASA, if you were walking on the surface of Mars, the Earth and Moon would be visible to the naked eye and would appear as "bright evening stars." This is only one of a handful of times that Earth has been imaged from more than a few thousand miles away. It's always rather humbling to see Earth -- that mote of dust suspended in a sunbeam -- just sitting there, tiny and insignificant, dwarfed by the grandest of black expanses.