How Nasa got Earth to Photobomb Saturn

Editing the result into something beautiful

On 19 July 2013, Nasa did something slightly unusual — but close to our hearts. The agency told Earthlings to look up and smile.

The occasion was a family photo of the inner solar system, taken from Cassini, orbiting Saturn. From this distance, Earth appears as nothing but a pale blue dot, and the other interior planets don’t fare much better. But it was a rare chance to have the whole family in one photo without the optical interference of the Sun, so Nasa didn’t want to miss it.

NASA / JPL Caltech / SSI

For four hours, Cassini snapped more than 300 images using both its wide-angle and narrow-angle cameras aimed at Saturn. The resulting mosaic of shots was edited down the 141 that comprise the image you see above. Mars, Venus, Earth, Saturn and most of their accompanying moons in one photo, shining in the heavens.

Like most family portraits, a bit of Photoshopping was required to get everyone looking their best. As well as narrowing down the selection to just half of the shots captured, it also boosted the brightness of Earth, Venus, Mars, and Saturn’s moons Enceladus, Epimetheus and Pandora by a factor of eight and a half, and Tethys by a factor of four.

The background starfield was brightened by factors ranging from six to sixteen, and the outer rings were brightened between two and eight times relative to the super-bright inner rings. Nasa tactfully says of this touching-up process: “This version was processed for balance and beauty.”

Here’s a fully annotated version, click here for bigger: