Skip to main content

NASA's decades-old Voyager 2 mission is a preview of new mission to Pluto

By Shelby Lin Erdman, CNN
updated 9:53 PM EDT, Tue August 26, 2014
NASA's New Horizons spacecraft is the first probe sent to Pluto, and it's scheduled to arrive in July 2015. This is an artist's concept of the spacecraft flying past Pluto. NASA's New Horizons spacecraft is the first probe sent to Pluto, and it's scheduled to arrive in July 2015. This is an artist's concept of the spacecraft flying past Pluto.
HIDE CAPTION
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
Pluto on the horizon
<<
<
1
2
3
4
5
6
7
8
>
>>
STORY HIGHLIGHTS
  • NASA's New Horizons mission hurtles toward Pluto in historic 3 billion mile expedition
  • New Horizons is set to reach the "dwarf planet" in July 2015
  • NASA marks anniversary of Voyager 2 mission to Neptune and its moon Triton
  • NASA: Voyager 2 mission offers a preview of sorts of New Horizons journey

(CNN) -- NASA's New Horizons explorer is hurtling through space on its way to the outermost reaches of the solar system for a rendezvous with the small, icy "dwarf planet" of Pluto and its five moons.

It's a staggering decade-long, 3 billion mile journey that started with the New Horizons launch in 2006. The space probe is expected to reach Pluto next summer, the only spacecraft to visit it. It's also only the fifth probe to ever journey so far from the sun across such vast reaches of space, according to NASA officials.

New Horizons is reminiscent of another historic undertaking: NASA's Voyager 2 mission to Neptune. Monday marks the 25th anniversary of Voyager's fly-by of Neptune and its moon Triton on August 25, 1989. The mission gave humanity its first close-up glimpse of the eighth planet from the sun and its largest satellite.

Marking the 25th anniversary, NASA has released a global color map of Triton using Voyager's extraordinary footage of the moon and a video of the fly-by. The space agency says the map's colors are a close approximation of the moon's natural colors.

NASA released a global color map of Neptune\'s moon, Triton, to mark the 25th anniversary of Voyager\'s fly-by of the planet and its moon.
NASA released a global color map of Neptune's moon, Triton, to mark the 25th anniversary of Voyager's fly-by of the planet and its moon.

NASA says the image of Triton and video provides a sneak peek of what scientists expect when New Horizons reaches Pluto.

"Although Triton is a moon of a planet and Pluto is a dwarf planet, Triton serves as a preview of sorts for the upcoming Pluto encounter," NASA said on its website.

But the space agency also says it expects great differences in the large moon and the dwarf planet.

"Although both bodies originated in the outer solar system, Triton was captured by Neptune and has undergone a radically different thermal history than Pluto. Tidal heating has likely melted the interior of Triton, producing the volcanoes, fractures and other geological features that Voyager saw on that bitterly cold, icy surface."

Pluto, which is slightly smaller than Triton, will likely be very different from Neptune's large moon, but researchers expect the dwarf planet to have similar features to Triton, including internal density and bulk composition, and similarly low temperatures on its frozen surface.

Voyager also discovered atmospheric plumes on Triton, according to NASA.

The discovery, said NASA researchers, made it "one of the active known bodies in the outer solar system, along with ... Jupiter's moon Io and Saturn's moon Enceladus."

Scientists are hoping the New Horizons mission will help establish whether Pluto or its largest moon, Charon, falls into this category.

A sequence of 12 images shows Charon orbiting Pluto in July 2014.
NASA

Space agency officials caution, however, when New Horizons makes its closest fly-by of Pluto on July 14, 2015, "it will not be a replay of Voyager, but more of a sequel and a reboot."

New Horizons is more technologically advanced than Voyager, and it's also exploring a whole new planetary system, so researchers expect to make new discoveries.

Monday, August 25, also marks another milestone anniversary for NASA: Two years ago, Voyager 1 reached interstellar space, defined by Voyager Project Scientist Dr. Ed Stone as "the space between the stars."

ADVERTISEMENT
Part of complete coverage on
Space
updated 3:29 PM EDT, Sat September 20, 2014
This image from the Hubble Space Telescope indicates that a huge ring of dark matter likely exists surrounding the center of CL0024+17 that has no normal matter counterpart.
Scientists are closer to seeing a vast, invisible universe as a spectrometer in Earth orbit picks up possible clues of dark matter.
updated 9:21 AM EDT, Wed September 10, 2014
The Soviets sent stray dogs up to conquer space. This is what happened next
updated 5:20 AM EDT, Thu August 28, 2014
Scientists believe that a hot gas bubble was formed by multiple supernovas.
updated 11:47 AM EDT, Wed August 27, 2014
Robonaut is the next generation dexterous robot
Life aboard the International Space Station.
updated 9:53 PM EDT, Tue August 26, 2014
NASA's New Horizons mission hurtles toward Pluto in historic 3 billion mile expedition.
updated 4:44 PM EDT, Wed August 6, 2014
Rosetta spacecraft arrives at its destination, Comet 67P after a 10-year journey around the solar system.
After a 10-year chase the Rosetta spacecraft is now orbiting a comet
updated 4:16 PM EDT, Fri July 25, 2014
"Here comes the sun" indeed, and it was just barely all right.
updated 12:53 PM EDT, Wed July 23, 2014
Seems NASA's fascination with the moon is in the past. It's focused on something far more menacing: incoming asteroids
updated 11:56 PM EDT, Mon July 14, 2014
Scientists looking for signs of life in the universe -- as well as another planet like our own -- are a lot closer to their goal than people realize.
updated 3:39 PM EDT, Mon August 25, 2014
The U.S. Army brainchild "Project Horizon" was born. Its proposal to leap beyond the Soviets opened with the line: "There is a requirement for a manned military outpost on the moon."
updated 3:43 PM EDT, Mon August 25, 2014
solar flare july 2014
From Earth, the sun appears as a constant circle of light, but when viewed in space a brilliant display of motion is revealed.
updated 1:31 PM EDT, Thu July 17, 2014
The full moons of this summer -- July 12, August 10 and September 9 -- are supermoons, as NASA calls them.
updated 11:51 AM EDT, Sun June 29, 2014
If you think you saw a flying saucer over Hawaii, you might not be crazy -- except what you saw didn't come from outer space, though that may be its ultimate destination.
updated 9:47 PM EDT, Thu June 26, 2014
The U.S. space shuttle program retired in 2011, leaving American astronauts to hitchhike into orbit. But after three long years, NASA's successor is almost ready to make an entrance.
updated 10:21 AM EDT, Fri June 13, 2014
When I first poked my head inside Virgin Galactic's newest spaceship, I felt a little like I was getting a front-row seat to space history.
updated 7:03 PM EDT, Tue June 10, 2014
The sun is putting on a fireworks show again.
updated 7:02 PM EDT, Tue June 24, 2014
A year is a very long time on Mars -- 687 days. NASA's Curiosity rover can attest that it's enough time for some unexpected life changes.
updated 2:00 PM EDT, Fri May 2, 2014
At least one corner of the solar system may be serving up an ice-and-water sandwich, with the possibility of life on the rocks.
updated 11:55 AM EDT, Tue April 8, 2014
You can't see it happening on Earth, but space itself is stretching. Ever since the Big Bang happened 13.8 billion years ago, the universe has been getting bigger.
updated 3:27 PM EST, Tue February 25, 2014
From a sheep ranch in Western Australia comes the oldest slice of Earth we know.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT