Night colors--Aurora Borealis, the Moon, and Moscow at night A thin green line of the aurora borealis crosses the top of this image taken from the International Space Station s. The moon appears as a white disc just above the aurora. Airglow appears as a blue-white cusp on the Earth's limb. Russia's capital city Moscow makes a splash of yellow lower left, with its easily recognized radial pattern of highways. Other cities are Nizhni Novgorod (image lower center) 400 km from Moscow, St. Petersburg (image left) 625 km from Moscow, and Finland's capital city Helsinki.