There's really no doubt that astronomical cycles have influenced the growth and decay of ice on planet earth for the last 5 million years or so. (tamino.wordpress.com)
Since at least the 1960s, astronauts and satellites have been snapping photos of planet Earth from on high. (scientificamerican.com)
If you're a human from planet earth this can work for you too. (alldayenergydiet.com)