Reprinted by NASA.
Thirty years ago, on August 25, 1
Voyager's planetary program was really an opportunity to show the public what science is all about. Every day we learned something new.
Wrapped in blue-green and cobalt-colored cloud bands, the planet revealed by Voyager 2 looked like a blue-colored sibling to Jupiter and Saturn, with the blue indicating the presence of methane. A massive, slate-colored storm was called the Great Dark Spot, much like Jupiter's Great Red Spot. Six new moons and four rings were discovered.
During the encounter, the engineering team carefully changed the direction and speed of the probe so that it could scan the planet's largest moon, Triton, at close range. The flyby showed evidence of geologically young surfaces and active geysers spewing material into the sky. This indicated that Triton was not a solid ball of ice although it had the lowest surface temperature of a natural body observed by Voyager: minus 235 degrees Celsius.
The completion of the Neptune flyby was marked The beginning of the interstellar Voyager mission that continues today, 42 years after launch. Voyager 2 and his twin, Voyager 1 (also flown by Jupiter and Saturn) continue to send shipments from the outer reaches of our solar system. At the time of the encounter with Neptune, Voyager 2 was about 4.7 billion kilometers from Earth. Today it is 18 billion kilometers from us. The faster-moving Voyager 1 is 21 billion kilometers from Earth.
When Voyager reached 2 Neptune, the Voyager mission team had completed five planetary encounters. However, the big blue planet still poses unique challenges.
About 30 times farther from the Sun than Earth, the Ice Giant receives only about 0.001 times the amount of sunlight it causes. In such low light conditions, the Voyager 2 camera needed longer exposure times to get high-quality images. However, because the spacecraft would reach a top speed of 90,000 km / h (60,000 mph) relative to the earth, a long exposure time would blur the image. (Imagine trying to photograph a road sign from the window of a fast-moving car.)
So the team programmed the Voyager 2 engines to shoot gently during the approach and turn the spaceship so that the camera is not focused on the target, interrupting the overall speed and direction of the spaceship.
The great distance of the probe also meant that the radio signals from Voyager 2, when they reached the Earth, were weaker than those of other fly-bys. However, the spaceship had the advantage of time: The Voyagers communicate with Earth via the Deep Space Network (DSN), which uses radio antennas at locations in Madrid (Spain). Canberra, Australia; and Goldstone, California. During the Uranus encounter with Voyager 2 in 1986, the three largest DSN antennas were 64 meters wide. To support the encounter with Neptune, the DSN extended the harness to 70 meters. This included non-DSN antennas nearby to collect data, including another 64-meter antenna in Parkes, Australia, and several 25-meter antennas at the Very Large Array in New Mexico.
The engineers could hear the Voyager loud and clear. It also increased how much data could be sent back to Earth in a given amount of time so that the spacecraft could send back more images of the flyby.
The week before this close encounter in August 1989, the atmosphere in the Jet Propulsion Laboratory of NASA in Pasadena, California, which manages the Voyager mission, was electrifying. During the four-hour voyage to Earth taken by Voyager 2 during its Neptune approach, members of the Voyager team gathered around computer screens to see the lab. Stone said:
One of the things that distinguished Voyager's planetary encounters from today's missions was that there was no Internet that allowed the entire team and the whole world to see the images at the same time. The images were available in real time in a limited number of locations.
However, the team was eager to inform the public as soon as possible so they could share their discoveries with the world daily from 21 to 29 August. On August 24, a broadcast titled Voyager All Night sent regular updates of the planet's closest encounter with the planet, which took place on August 24 at 4:00 am (9:00 pm in California).
The following morning, Vice President Dan Quayle visited the lab to praise the Voyager team. That night, Chuck Berry, whose song Johnny B. Goode was included in the Golden Record that flew with both Voyagers, starred in JPL's celebration of heroism.
Of course, Voyager's achievements go well beyond the historic week three decades ago. Both probes have now entered interstellar space after leaving the heliosphere – the protective bubble around the planets, created by a rapid flow of particles and magnetic fields directed outward by our sun.
They tell Earth about the "weather". and conditions from this region, filled with debris from stars that exploded elsewhere in our galaxy. They have taken the first weak step of humanity into the cosmic ocean, in which no other operational probes have flown.
Voyager data also complements other missions, including NASA's Interstellar Boundary Explorer (IBEX), which remotely detects the boundary where particles of our Sun collide with material from the rest of the galaxy. And NASA is preparing the Interstellar Mapping and Accelerator Probe (IMAP), which is scheduled to launch in 2024, to use the Voyager's observations fridge light bulb. Stone said:
Every day they travel somewhere where human probes have never been. Forty-two years after the start, they are still on a journey of discovery.
More information about the Voyager mission can be found at https://voyager.jpl.nasa.gov/[19659006lightboxesForwardpicturesfromNeptunecontouredbyVoyager2visitView:https://voyagerjplnasagov/galleries/images-voyager-took/neptune/[19659033+GreaterblueMoonNeptunnextmallbluehalfmoonTriton"width="800"height="572"class="size-fullwp-image-204904"/>
Conclusion: It's been 30 years since Voyager 2 Neptune in the Voyager's grand tour through the four giant planets of our solar system, to date no other terrestrial spaceship has returned to Neptune.
Read more: Voyager Mission Fact Sheet