Tag Archives: Neptune

Flying Past Neptune’s Moon Triton 

Image Credit: Voyager 2, JPL, NASA; Digital composition: Paul Schenk (LPI, USRA)

 What would it look like to fly past Triton, the largest moon of planet Neptune? Only one spacecraft has ever done this – and now, for the first time, images of this dramatic encounter have been gathered into a movie. On 1989 August 25, the Voyager 2 spacecraft shot through the Neptune system with cameras blazing. Triton is slightly smaller than Earth’s Moon but has ice volcanoes and a surface rich in frozen nitrogen. The first sequence in the video shows Voyager’s approach to Triton, which, despite its unusual green tint, appears in approximately true color. The mysterious terrain seen under the spacecraft soon changed from light to dark, with the terminator of night soon crossing underneath. After closest approach, Voyager pivoted to see the departing moon, now visible as a diminishing crescent. Next July, assuming all goes well, the robotic New Horizons spacecraft will make a similar flight past Pluto, an orb of similar size to Triton.

APOD NASA 26-Aug-14

Voyager’s Neptune 

Neptune-South-Pole-Voyager-2_2327x1670
Composite Image Credit & Copyright: Assembly/Processing – Rolf Olsen,
Data – Voyager 2, NASA Planetary Data System

Cruising through the outer solar system, the Voyager 2 spacecraft made its closest approach to Neptune on August 25, 1989, the only spacecraft to visit the most distant gas giant. Based on the images recorded during its close encounter and in the following days, this inspired composited scene covers the dim outer planet, largest moon Triton, and faint system of rings. From just beyond Neptune’s orbit, the interplanetary perspective looks back toward the Sun, capturing the planet and Triton as thin sunlit crescents. Cirrus clouds and a dark band circle Neptune’s south polar region, with a cloudy vortex above the pole itself. Parts of the very faint ring system along with the three bright ring arcs were first imaged by Voyager during the fly-by, though the faintest segments are modeled in this composited picture. Spanning 7.5 degrees, the background starfield is composed from sky survey data centered on the constellation Camelopardalis, corresponding to the outbound Voyager’s view of the magnificent Neptunian system.

NASA APOD 15-May-14

Despina, Moon of Neptune

neptune_despina_transit_combo_despinabrightened

Image Credit: NASA, JPL – Processed Image Copyright: Ted Stryk

Despina is a tiny moon of Neptune. A mere 148 kilometers across, diminutive Despina was discovered in 1989, in images from the Voyager 2 spacecraft taken during its encounter with the solar system’s most distant gas giant planet. But looking through the Voyager 2 data 20 years later, amateur image processor and philosophy professor Ted Stryk discovered something no one had recognized before — images that show the shadow of Despina in transit across Neptune’s blue cloud tops. His composite view of Despina and its shadow is composed of four archival frames taken on August 24, 1989, separated by nine minutes. Despina itself has been artificially brightened to make it easier to see. In ancient Greek mythology, Despina is a daughter of Poseidon, the Roman god Neptune.

APOD NASA 16-Jan-2014