The Day the Earth Smiled: Sneak Preview
Date: 19 Jul 2013
In this rare image taken on 19 July 2013, the wide-angle camera on NASA's Cassini spacecraft has captured Saturn's rings and our planet Earth and its moon in the same frame. It is only one footprint in a mosaic of 33 footprints covering the entire Saturn ring system (including Saturn itself). At each footprint, images were taken in different spectral filters for a total of 323 images: some were taken for scientific purposes and some to produce a natural color mosaic. This is the only wide-angle footprint that has the Earth-moon system in it.
The dark side of Saturn, its bright limb, the main rings, the F ring, and the G and E rings are clearly seen; the limb of Saturn and the F ring are overexposed. The "breaks" in the brightness of Saturn's limb are due to the shadows of the rings on the globe of Saturn, preventing sunlight from shining through the atmosphere in those regions. The E and G rings have been brightened for better visibility.
Earth, which is 1.44 billion km (898 million miles) away in this image, appears as a blue dot at center right; the moon can be seen as a fainter protrusion off its right side. An arrow indicates their location in the annotated version. (The two are clearly seen as separate objects in the accompanying composite image: PIA14949.) The other bright dots nearby are stars.
This is only the third time ever that Earth has been imaged from the outer solar system. The acquisition of this image, along with the accompanying composite narrow- and wide-angle image of Earth and the moon and the full mosaic from which both are taken, marked the first time that inhabitants of Earth knew in advance that their planet was being imaged. That opportunity allowed people around the world to join together in social events to celebrate the occasion.
This view looks toward the unilluminated side of the rings from about 20 degrees below the ring plane.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on 19 July 2013 at a distance of approximately 1.212 million km (753,000 miles) from Saturn, and approximately 1.445858 billion km (898.414 million miles) from Earth. Image scale on Saturn is 69 km (43 miles) per pixel; image scale on the Earth is 86,620 km (53,820 miles) per pixel. The illuminated areas of neither Earth nor the moon are resolved here. Consequently, the size of each "dot" is the same size that a point of light of comparable brightness would have in the wide-angle camera.
Credit: NASA/JPL-Caltech/Space Science Institute