August 24, 2014
NASA Releases New Map Of Neptune’s Moon Triton To Mark 25th Anniversary Of Voyager 2’s Visit
redOrbit Staff & Wire Reports - Your Universe Online
In honor of the 25th anniversary of Voyager 2’s first up-close look at Neptune and Triton, NASA has “restored” footage obtained by the probe and used it to construct the highest-quality global color map of the moon to date.
According to the US space agency, the map was produced by Dr. Paul Schenk, a scientist at the Houston-based Lunar and Planetary Institute (http://www.lpi.usra.edu/) (LPI), and has also been used to develop a movie recreating the historic Voyager 2 encounter that took place on August 25, 1989.
[ Watch the Video: Sailing Past Neptune’s Moon Triton ]
The new map of Triton has a resolution of 1,970 feet (600 meters) per pixel, NASA explained, and the colors have been enhanced to emphasize contrast while still attempting to closely approximate the natural colors of the moon. Originally, the map was produced using orange, green and blue filter images, they noted.
Unfortunately, at the time of Voyager’s arrival at Triton, most of the moon’s northern hemisphere was in darkness and could not be observed by the spacecraft. Due to the speed of the visit, and the slow rotation of the moon, only one of Triton’s hemispheres could been seen at close distance, while the rest of the surface was either dark or blurry.
Among the improvements to the map are more accurate feature locations, the enhancement of feature details, the removal of some of the camera’s blurring effects, and improved color processing.
In addition to the 25th anniversary of the spacecraft’s arrival at Neptune, NASA officials said the new map of Triton was inspired in part by New Horizons’ upcoming encounter with Pluto, which is expected to occur on July 14, 2015. NASA said the flyby “will not be a replay of Voyager but more of a sequel and a reboot, with a new and more technologically advanced spacecraft and, more importantly, a new cast of characters.”
Even though Triton is a moon and Pluto is a dwarf planet, NASA said that Neptune’s moon “serves as a preview of sorts” for next year’s encounter with Pluto and its five known moons, which will be observed for the first time next summer. The agency added that while Triton “may not be a perfect preview of coming attractions, but it serves as a prequel to the cosmic blockbuster expected when New Horizons arrives at Pluto next year.”
While both bodies were formed in the outer solar system, Triton was captured by Neptune, and as a result, its thermal history had been radically different than that of Pluto’s, the space agency explained. The moon’s interior was likely melted by tidal heating, and that resulted in the volcanoes, fractures and other features observed by Voyager on the otherwise bitterly cold and ice-covered surface. Pluto is expected to possess some of the same features.
“Triton is slightly larger than Pluto, has a very similar internal density and bulk composition, and has the same low-temperature volatiles frozen on its surface,” NASA explained. “The surface composition of both bodies includes carbon monoxide, carbon dioxide, methane and nitrogen ices.”
“Voyager also discovered atmospheric plumes on Triton, making it one of the known active bodies in the outer solar system, along with objects such as Jupiter's moon Io and Saturn's moon Enceladus,” the agency added. “Scientists will be looking at Pluto next year to see if it will join this list. They will also be looking to see how Pluto and Triton compare and contrast, and how their different histories have shaped the surfaces we see.”
August 25 also marks the two-year anniversary of Voyager 1 departing the heliosphere and passing into interstellar space, although recent research has called into question if it had actually passed that threshold. Last month, Voyager scientists George Gloeckler and Len Fisk devised a test which they claimed would definitively prove whether or not the probe had actually exited the magnetic bubble surrounding the sun and planets and reached the space between the stars.