Craters and Shadows at the Lunar Terminator

Why does the right part of this image of the Moon stand out? Shadows. The terminator line — the line between light and dark — occurs in the featured image so that just over half the Moon’s face is illuminated by sunlight. The lunar surface appears different nearer the terminator because there the Sun is nearer the horizon and therefore causes shadows to become increasingly long. These shadows make it easier for us to discern structure, giving us depth cues so that the two-dimensional image, when dominated by shadows, appears almost three-dimensional. Therefore, as the Moon fades from light to Read more »

Jupiter Cloud Animation from Juno

How do Jupiter’s clouds move? To help find out, images taken with NASA’s Juno spacecraft during its last pass near Jupiter have been analyzed and digitally extrapolated into a time-lapse video. The eight-second time-lapse video, digitally extrapolated between two images taken only nine minutes apart, estimates how Jupiter’s clouds move over 29 hours. Abstractly, the result appears something like a psychedelic paisley dream. Scientifically, however, the computer animation shows that circular storms tend to swirl, while bands and zones appear to flow. This overall motion is not surprising and has been seen on time-lapse videos of Jupiter before, although never Read more »

Orbital ATK Rocket Rolls Out for May 21 Launch

An Orbital ATK rocket rolls out to launch Pad-0A at NASA’s Wallops Flight Facility on May 17, 2018, in advance of a May 21 launch from Wallops Island, VA. The Antares will launch a Cygnus spacecraft on a cargo resupply mission to the International Space Station. via NASA