HiRise, The Earth and Moon as Seen from Mars (PSP_005558_9040):

“This is an image of Earth and the Moon, acquired at 5:20 a.m. MST on 3 October 2007, at a range of 142 million kilometers, which gives the HiRISE image a scale of 142 km/pixel and an Earth diameter of about 90 pixels and a Moon diameter of 24 pixels. The phase angle is 98 degrees, which means that less than half of the disks of the Earth and Moon have direct illumination. We could image Earth/Moon at full disk illumination only when they are on the opposite side of the sun from Mars, but then the range would be much greater and the image would show less detail.”

Earth and Moon from Galileo probe, 1990 januari 02. (NASA)

Bernard Foing, If We Had No Moon:

“The Earth has a large moon, making it unique in the inner solar system. Mercury and Venus have no moons, and Mars has only two small asteroid-sized objects orbiting it. In this essay, the father of the SMART-1 lunar mission, Bernard Foing of the European Space Agency, looks at the effect the Moon has had on the Earth, and explores how different our world would be if we had no planetary companion. Would life have evolved differently, or even appeared on Earth without the Moon?”

(Via BoingBoing.)