On approach in July this year, the cameras on NASA’s New Horizons spacecraft captured Pluto rotating over the course of a full “Pluto day.” The best available images of each side of the dwarf planet taken during approach have been combined to create this view of a full rotation.
Pluto’s day is 6.4 Earth days long. The images were taken by the Long Range Reconnaissance Imager (LORRI) and the Ralph/Multispectral Visible Imaging Camera as the distance between New Horizons and Pluto decreased from 8 million kilometres (5 million miles) on 7 July to 645,000 kilometres (400,000 miles) on 13 July. The more distant images contribute to the view at the 3 o’clock position, with the top of the heart-shaped, informally named Tombaugh Regio slipping out of view, giving way to the side of Pluto that was facing away from New Horizons during closest approach on 14 July. The side New Horizons saw in most detail – what the mission team calls the “encounter hemisphere” – is at the 6 o’clock position.
These images and others like them reveal many details about Pluto, including the differences between the encounter hemisphere and the so-called “far side” hemisphere seen only at lower resolution. Dimples in the bottom (south) edge of Pluto’s disc are artifacts of the way the images were combined to create these composites.
Charon – like Pluto – rotates once every 6.4 Earth days. The photos were taken by LORRI and Ralph/MVIC from the 7 to the 13 July, as New Horizons closed in over a range of 10.2 million kilometres (6.4 million miles). The more distant images contribute to the view at the 9 o’clock position, with few of the signature surface features visible, such as the cratered uplands, canyons, or rolling plains of the informally named Vulcan Planum. The side New Horizons saw in most detail, during closest approach on 14 July, is at the 12 o’clock position.
These images and others like them reveal many details about Charon, including how similar looking the encounter hemisphere is to the so-called “far side” hemisphere seen only at low resolution – which is the opposite of the situation at Pluto. Dimples in the bottom (south) edge of Charon’s disc are artifacts of the way the New Horizons images were combined to create these composites.