Shining back at the Moon

When sunlight hits Earth, a part of it is reflected into space by clouds, ice, and Earth’s surface. The ratio of reflected light to incoming light is called the albedo. In climate models, it is an important parameter as it indicates how much energy enters Earth’s system.

One way to calculate albedo is to use the Moon as a projection screen, by measuring the light that is reflected from the Moon, scientists can calculate how much comes from the Sun and how much is reflected from Earth. The Moon, however, needs to be at a specific moment in its orbit: the new Moon phase. During this period, less of the visible part of the Moon is illuminated by the Sun, and more will be lit up by the light reflected from Earth.

Many images of our Moon have been taken from ground using telescopes on Earth, but our atmosphere disturbs these observations. As taking images from space removes our atmosphere from the equation, Andreas will take hundreds of images of the Moon from the International Space Station’s Cupola observatory.