We seldom see this perspective which is what makes it so fascinating, so I selected it for one of my first blog images. The distance to the moon is about 30 of earth’s diameters and this photo was taken from about 2.2 million miles away.
As 2001 Mars Odyssey receded from Earth, it captured a departing view of its home planet and the Moon. This view is in thermal infrared wavelengths, so brightness and darkness represents more or less heat being emitted from the globes. The dark spot on Earth is the cold south pole; the bright spot above it is the warm land surface of Australia. Mars Odyssey was more than 3.5 million kilometers (2.2 million miles) from Earth and the Moon when it took this photo, and achieved a resolution of about 900 kilometers. From this distance and perspective the camera was able to acquire an image that directly shows the true distance from Earth to the Moon. Earth’s diameter is about 12,750 kilometers (7,922 miles), and the distance from Earth to the Moon is about 385,000 kilometers (239,000 miles), corresponding to 30 Earth diameters.
Credit: NASA / JPL / U. Arizona