Last month NASA took took a picture (above) of Earth from a very unique perspective. The image shows the illuminated dark side of the moon crossing the Earth. It was captured by the Deep Space Climate Observatory (DSCOVR) using its Earth Imaging Camera (EPIC), 1.5 million miles from Earth. The primary mission of the DSCOVR satellite is to monitor solar winds in real time.
This image is interesting for two reasons. First it shows the dark side of the moon. We can not see this side the of the moon from Earth. We literally have to travel behind the moon to see this face. This is because of the manner in which the moon orbits the Earth. The moon is tidally locked to the Earth. This means that for every one orbit around the Earth, the moon rotates around its axis once as well. Translation: we always we the same face of the moon from Earth. Humans did not see the far side of the moon until 1959, when the Soviet Luna 3 probe first photographed it.
The second reason that this image is awesome is that it was collected from a Lagrange point, specifically L1.
The image above shows the five Lagrange points of the Earth and the Sun. At a Lagrange point, the gravitational pull from the Earth and the sun cancel each other out. In this case the DSCOVR satellite is located at L1 in the image above. The reason that this precise satellite position was chosen was to maintain a stable position between the Earth and the Sun.
The images of the animation below were taken between 3:50 pm and 8:45 pm EDT on Jul 16, 2015. The DSCOVR satellite will capture images of the dark side of the moon traversing in front of the moon about twice a year.