On approach in July 2015, 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 Pluto taken during approach have been combined to create this view of a full rotation. Click the image for a full-size version. Image credits: NASA/JHUAPL/SwRI.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 5 million miles (8 million kilometres) on 7 July to 400,000 miles (about 645,000 kilometres) 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 2015. 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.On approach to the Pluto system in July 2015, the cameras on NASA’s New Horizons spacecraft captured images of the largest of Pluto’s five moons, Charon, rotating over the course of a full day. The best currently available images of each side of Charon taken during approach have been combined to create this view of a full rotation of the moon. Click the image for a full-size version. Image credits: NASA/JHUAPL/SwRI.Charon — like Pluto — rotates once every 6.4 Earth days. The photos were taken by the Long Range Reconnaissance Imager (LORRI) and the Ralph/Multispectral Visible Imaging Camera from 7-13 July, as New Horizons closed in over a range of 6.4 million miles (10.2 million kilometres). 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 2015, 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.
Pluto’s “icy heart” is a bright, two-lobed feature on its surface that was discovered by NASA’s New Horizons team in 2015. The heart’s western lobe, informally named Sputnik Planitia, is a deep basin generally thought to have been created by a smaller body striking Pluto at extremely high speed, but a new study suggests a different origin.
A subsurface ocean lies deep within Saturn’s moon Dione, according to new data from the Cassini mission. Two other moons of Saturn, Titan and Enceladus, are already known to hide global oceans beneath their icy crusts. Researchers believe that Dione’s crust floats on an ocean several tens of kilometres deep located 100 kilometres below the surface.
Global stereo mapping of Pluto’s surface is now possible (requires red/blue glasses for viewing in 3-D), as images taken from multiple directions are downlinked from NASA’s New Horizons spacecraft. Stereo images will eventually provide an accurate topographic map of most of the hemisphere of Pluto seen by New Horizons, which will be key to understanding the dwarf planet’s geological history.
