Final answer:
Dr. George R Carruthers invented a UV imaging spectrograph in 1969 for moon missions, which notably captured the first ultraviolet photographs of Earth, revealing the hydrogen atmosphere and other atmospheric phenomena.
Step-by-step explanation:
In 1969, Dr. George R Carruthers invented a ground-breaking spectrograph that was designed for use on the moon. This UV imaging device was remarkable because it enabled the capture of ultraviolet images without the interference of Earth's atmosphere. Its most significant achievement, and perhaps the one it is most known for, was capturing unprecedented images of Earth. This was monumental as it was the first time the Earth had been photographed in ultraviolet light from a distance, allowing for the observation of Earth's hydrogen atmosphere, polar auroras, and the tropical airglow belt.