"Long before it's in the papers"
January 27, 2015

RETURN TO THE WORLD SCIENCE HOME PAGE


Movie recreates in detail past visit to far-off moon

Aug. 26, 2014
Courtesy of NASA Jet Propulsion Laboratory
and World Science staff

Us­ing old foot­age, sci­en­tists work­ing with NASA have made a mov­ie said to real­is­tic­ally sim­u­late a vis­it a quarter-century ago to a moon far out in the so­lar sys­tem.

Triton, which is is 2,706 km wide, as seen by Voyager 2. Click to see the movie.


NASA’s Voy­ag­er 2 space­craft flew by the plan­et Nep­tune and its moon Tri­ton on Aug. 25, 1989, giv­ing hu­man­ity its first close-up look at both. Now, Paul Schenk, a sci­ent­ist at the Lu­nar and Plan­e­tary In­sti­tute in Hous­ton, has used the foot­age to build what NASA calls the best glob­al col­or map of the strange moon. The mov­ie is based in turn on that map. Both are on­line here.

The map has enough de­tail to show fea­tures 1,970 feet (600 me­ters) apart. Col­ors were en­hanced to br­ing out con­trast but closely ap­prox­i­mate the nat­u­ral ones, ac­cord­ing to the space agen­cy. The mov­ie shows only the moon’s south­ern hemisphere clear­ly, be­cause the moon did­n’t turn enough dur­ing the vis­it to clearly show both hemisphe­res and most of the north­ern side was in dark­ness that year.

The new proj­ect was in­spired by an­ti­cipa­t­ion of the agen­cy’s New Hori­zons en­coun­ter with Plu­to, com­ing up a lit­tle un­der a year from now, ac­cord­ing to NASA. Among the im­prove­ments are up­dates to the ac­cu­ra­cy of fea­ture loca­t­ions, sharp­en­ing of fea­ture de­tails by re­mov­ing some blur­ring ef­fects of the cam­era, and im­proved col­or pro­cess­ing.

Al­though Tri­ton is a moon of a plan­et and Plu­to is a dwarf plan­et, sci­en­tists say Tri­ton serves as a sort of pre­view for the upcom­ing Plu­to en­coun­ter. Si­m­i­lar­i­ties are ex­pected: the ob­jects have si­m­i­lar over­all make­up, and both came from the out­er so­lar sys­tem. Yet they have very dif­fer­ent his­to­ries: the slightly larg­er Tri­ton fell in­to Nep­tune’s or­bit and Plu­to did­n’t. Nep­tune’s gra­vity causes tid­al forc­es on its moon, heat­ing it up and likely melt­ing its in­te­ri­or, sci­en­tists ex­plain, pro­duc­ing the vol­ca­noes, frac­tures and oth­er fea­tures that Voy­ag­er saw on that bit­terly cold realm.

Voy­ag­er al­so found at­mos­pher­ic plumes, or ejec­tions of ma­te­ri­al, 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. Sci­en­tists will ex­am­ine Plu­to to see if it will join this list. That planned, brief en­coun­ter next July 14 will not be a re­play of Voy­ag­er but more of a se­quel and a “re­boot,” ac­cord­ing to NASA, with a new and more ad­vanced space­craft and a new cast of char­ac­ters. Those are Plu­to and its five known moons, all to be seen up close for the first time.


* * *

Send us a comment on this story, or send it to a friend

Sign up for
e-newsletter
   
 
subscribe
 
cancel

On Home Page         

LATEST

  • St­ar found to have lit­tle plan­ets over twice as old as our own

  • “Kind­ness curricu­lum” may bo­ost suc­cess in pre­schoolers

EXCLUSIVES

  • Smart­er mice with a “hum­anized” gene?

  • Was black­mail essen­tial for marr­iage to evolve?

  • Plu­to has even cold­er “twin” of sim­ilar size, studies find

  • Could simple an­ger have taught people to coop­erate?

MORE NEWS

  • F­rog said to de­scribe its home through song

  • Even r­ats will lend a help­ing paw: study

  • D­rug may undo aging-assoc­iated brain changes in ani­mals

Using old footage, scientists working with NASA have created a movie designed to realistically simulate a visit a quarter-century ago to a moon far out in the solar system. NASA’s Voyager 2 spacecraft flew by the planet Neptune and its moon Triton on Aug. 25, 1989, giving humanity its first close-up look at both. Now, Paul Schenk, a scientist at the Lunar and Planetary Institute in Houston, has used the footage to build what NASA calls the best global color map of the strange moon. The movie is based in turn on that map. Both are online here. The map has enough detail to show features 1,970 feet (600 meters) apart. Colors were enhanced to bring out contrast but closely approximate the natural ones, according to the space agency. The movie shows only the moon’s southern hemisphere clearly, because the moon didn’t turn enough during the visit to clearly show both hemispheres and most of the northern side was in darkness that year. The new project was inspired by anticipation of the agency’s New Horizons encounter with Pluto, coming up a little under a year from now, according to NASA. Among the improvements are updates to the accuracy of feature locations, sharpening of feature details by removing some blurring effects of the camera, and improved color processing. Although Triton is a moon of a planet and Pluto is a dwarf planet, scientists say Triton serves as a sort of preview for the upcoming Pluto encounter. Similarities are expected: the objects have similar overall makeup, and both came from the outer solar system. Yet they have very different histories: the slightly larger Triton fell into Neptune’s orbit and Pluto didn’t. Neptune’s gravity causes tidal forces on its moon, heating it up and likely melting its interior, scientists explain, producing the volcanoes, fractures and other features that Voyager saw on that bitterly cold realm. Voyager also found atmospheric plumes, or ejections of material, 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. Scientists will examine Pluto to see if it will join this list. That planned, brief encounter next July 14 will not be a replay of Voyager but more of a sequel and a “reboot,” according to NASA, with a new and more advanced spacecraft and a new cast of characters. Those are Pluto and its five known moons, all to be seen up close for the first time.