We’ve all seen incredible images of the Earth and moon. But, we’ve never seen them like NASA’s Deep Space Climate Observatory (DSCOVR) satellite did on July 16. Between 3:50 p.m. and 8:45 p.m., the DSCOVR satellite took a series of images as the moon moved across the sunlit face of the Earth.
You are looking at the fully illuminated “dark side” of the moon.
These epic images call for an epic camera. And the DSCOVR satellite has it covered. The images making up the animation above were captured with NASA’s Earth Polychromatic Imaging Camera (EPIC). It’s a four megapixel CCD camera and telescope aboard the satellite.
The most prominent dark side features seen above are Mare Moscoviense in the upper left and the Tsiolkovskiy crater in the lower left. You can also see a small sliver of shadowed area on the right edge. You see the weird green sliver near the shadow? That’s a camera artifact from the moon shifting position between the camera exposures.
The DSCOVR satellite sits one million miles away from Earth as it continuously observes the sun and the illuminated side of Earth. For comparison, the moon orbits the Earth at a distance of 238,900 miles (average).
How can DSCOVR stay in the same position? It sits at a unique orbiting position known as Lagrangian point 1 (L1). I’ll let the official DSCOVR website explain:
At L1, the gravitational forces between the sun and Earth balance the centrifugal forces of a satellite to provide a stable orbit point requiring fewer orbital corrections for the spacecraft to remain in its operational location for a longer period of time.
Here’s an image of the L1 orbit point.
This orbital point is incredibly handy for solar wind monitoring, which is one of DSCOVR’s primary missions. Besides keeping tabs on solar wind and helping NOAA better forecast solar storms, DSCOVR will also provide detailed observations of Earth. DSCOVR’s EPIC instrument will monitor ozone, vegetation, cloud height and aerosols in the Earth’s atmosphere.
Now that DSCOVR has reached its final orbit, EPIC will begin regular observations of Earth next month according to NASA. The space agency plans to release color images of Earth on a daily basis through a dedicated website. The images will be available 12 to 36 hours after they are captured.