Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Image: NASA
A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.
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And you can download it right here, for Mac, Windows, Linux, OS/2, and other open operating systems. About:
Mars24 is a Java application which displays a Mars sunclock, a graphical representation of the planet Mars showing its current sun- and nightsides, along with a numerical readout of the time in 24-hour format. Other displays include a plot showing the relative orbital positions of Mars and Earth and a diagram showing the solar angle and path for a given location on Mars.
Created at NASA's Goddard Institute for Space Studies.
And for iOS, this looks promising. Haven't tried it, and it's not a NASA product, so YMMV.