voyager 1 beyond the solar system

Voyager 1: Facts about Earth's farthest spacecraft

Voyager 1 continues to explore the cosmos along with its twin probe, Voyager 2.

The Grand Tour

Voyager 1 jupiter flyby, voyager 1 visits saturn and its moons, voyager 1 enters interstellar space, voyager 1's interstellar adventures, additional resources.

Voyager 1 is the first spacecraft to travel beyond the solar system and reach interstellar space . 

The probe launched on Sept. 5, 1977 — about two weeks after its twin Voyager 2 — and as of August 2022 is approximately 14.6 billion miles (23.5 billion kilometers) away from our planet, making it Earth 's farthest spacecraft. Voyager 1 is currently zipping through space at around 38,000 mph (17 kilometers per second), according to NASA Jet Propulsion Laboratory .

When Voyager 1 launched a mission to explore the outer planets in our solar system nobody knew how important the probe would still be 45 years later The probe has remained operational long past expectations and continues to send information about its journeys back to Earth. 

Related: Celebrate 45 years of Voyager with these amazing images of our solar system (gallery)

Elizabeth Howell, Ph.D., is a staff writer in the spaceflight channel since 2022. She was contributing writer for  Space.com  for 10 years before that, since 2012. Elizabeth's on-site reporting includes two human spaceflight launches from Kazakhstan, three space shuttle missions in Florida, and embedded reporting from a simulated Mars mission in Utah. 

Size: Voyager 1's body is about the size of a subcompact car. The boom for its magnetometer instrument extends 42.7 feet (13 meters). Weight (at launch): 1,797 pounds (815 kilograms). Launch date: Sept. 5, 1977

Jupiter flyby date: March 5, 1979

Saturn flyby date: Nov. 12, 1980.

Entered interstellar space: Aug. 25, 2012. 

The spacecraft entered interstellar space in August 2012, almost 35 years after its voyage began. The discovery wasn't made official until 2013, however, when scientists had time to review the data sent back from Voyager 1.

Voyager 1 was the second of the twin spacecraft to launch, but it was the first to race by Jupiter and Saturn . The images Voyager 1 sent back have been used in schoolbooks and by many media outlets for a generation. The spacecraft also carries a special record — The Golden Record — that's designed to carry voices and music from Earth out into the cosmos. 

According to NASA Jet Propulsion Laboratory (JPL) , Voyager 1 has enough fuel to keep its instruments running until at least 2025. By then, the spacecraft will be approximately 13.8 billion miles (22.1 billion kilometers) away from the sun.  

The Voyager missions took advantage of a special alignment of the outer planets that happens just once every 176 years. This alignment allows spacecraft to gravitationally "slingshot" from one planet to the next, making the most efficient use of their limited fuel.

NASA originally planned to send two spacecraft past Jupiter, Saturn and Pluto and two other probes past Jupiter, Uranus and Neptune . Budgetary reasons forced the agency to scale back its plans, but NASA still got a lot out of the two Voyagers it launched.

Voyager 2 flew past Jupiter, Saturn, Uranus and Neptune , while Voyager 1 focused on Jupiter and Saturn.

Recognizing that the Voyagers would eventually fly to interstellar space, NASA authorized the production of two Golden Records to be placed on board the spacecraft. Sounds ranging from whale calls to the music of Chuck Berry were placed on board, as well as spoken greetings in 55 languages. 

The 12-inch-wide (30 centimeters), gold-plated copper disks also included pictorials showing how to operate them and the position of the sun among nearby pulsars (a type of fast-spinning stellar corpse known as a neutron star ), in case extraterrestrials someday stumbled onto the spacecraft and wondered where they came from.

Both spacecraft are powered by three radioisotope thermoelectric generators , devices that convert the heat released by the radioactive decay of plutonium to electricity. Both probes were outfitted with 10 scientific instruments, including a two-camera imaging system, multiple spectrometers, a magnetometer and gear that detects low-energy charged particles and high-energy cosmic rays . Mission team members have also used the Voyagers' communications system to help them study planets and moons, bringing the total number of scientific investigations on each craft to 11.

Voyager 1 almost didn't get off the ground at its launch , as its rocket came within 3.5 seconds of running out of fuel on Sept. 5, 1977.

But the probe made it safely to space and raced past its twin after launch, getting beyond the main asteroid belt between Mars and Jupiter before Voyager 2 did. Voyager 1's first pictures of Jupiter beamed back to Earth in April 1978, when the probe was 165 million miles (266 million kilometers) from home.

According to NASA , each voyager probe has about 3 million times less memory than a mobile phone and transmits data approximately 38,000 times slower than a 5g internet connection.  

To NASA's surprise, in March 1979 Voyager 1 spotted a thin ring circling the giant planet. It found two new moons as well — Thebe and Metis. Additionally, Voyager 1 sent back detailed pictures of Jupiter's big Galilean moons ( Io , Europa , Ganymede and Callisto ) as well as Amalthea .

Like the Pioneer spacecraft before it , Voyager's look at Jupiter's moons revealed them to be active worlds of their own. And Voyager 1 made some intriguing discoveries about these natural satellites. For example, Io's many volcanoes and mottled yellow-brown-orange surface showed that, like planets, moons can have active interiors.

Additionally, Voyager 1 sent back photos of Europa showing a relatively smooth surface broken up by lines, hinting at ice and maybe even an ocean underneath. (Subsequent observations and analyses have revealed that Europa likely harbors a huge subsurface ocean of liquid water, which may even be able to support Earth-like life .)

Voyager 1's closest approach to Jupiter was on March 5, 1979, when it came within 174,000 miles (280,000 km) of the turbulent cloud tops. Then it was time for the probe to aim for Saturn.

Scientists only had to wait about a year, until 1980, to get close-up pictures of Saturn. Like Jupiter, the ringed planet turned out to be full of surprises.

One of Voyager 1's targets was the F ring, a thin structure discovered only the year previously by NASA's Pioneer 11 probe. Voyager's higher-resolution camera spotted two new moons, Prometheus and Pandora, whose orbits keep the icy material in the F ring in a defined orbit. It also discovered Atlas and a new ring, the G ring, and took images of several other Saturn moons.

One puzzle for astronomers was Titan , the second-largest moon in the solar system (after Jupiter's Ganymede). Close-up pictures of Titan showed nothing but orange haze, leading to years of speculation about what it was like underneath. It wouldn't be until the mid-2000s that humanity would find out, thanks to photos snapped from beneath the haze by the European Space Agency's Huygens atmospheric probe .

The Saturn encounter marked the end of Voyager 1's primary mission. The focus then shifted to tracking the 1,590-pound (720 kg) craft as it sped toward interstellar space.

Two decades before it notched that milestone, however, Voyager 1 took one of the most iconic photos in spaceflight history. On Feb. 14, 1990, the probe turned back toward Earth and snapped an image of its home planet from 3.7 billion miles (6 billion km) away. The photo shows Earth as a tiny dot suspended in a ray of sunlight. 

Voyager 1 took dozens of other photos that day, capturing five other planets and the sun in a multi-image "solar system family portrait." But the Pale Blue Dot picture stands out, reminding us that Earth is a small outpost of life in an incomprehensibly vast universe.

Voyager 1 left the heliosphere — the giant bubble of charged particles that the sun blows around itself — in August 2012, popping free into interstellar space. The discovery was made public in a study published in the journal Science the following year.

The results came to light after a powerful solar eruption was recorded by Voyager 1's plasma wave instrument between April 9 and May 22, 2013. The eruption caused electrons near Voyager 1 to vibrate. From the oscillations, researchers discovered that Voyager 1's surroundings had a higher density than what is found just inside the heliosphere.

It seems contradictory that electron density is higher in interstellar space than it is in the sun's neighborhood. But researchers explained that, at the edge of the heliosphere, the electron density is dramatically low compared with locations near Earth. 

Researchers then backtracked through Voyager 1's data and nailed down the official departure date to Aug. 25, 2012. The date was fixed not only by the electron oscillations but also by the spacecraft's measurements of charged solar particles. 

On that fateful day — which was the same day that Apollo 11 astronaut Neil Armstrong died — the probe saw a 1,000-fold drop in these particles and a 9% increase in galactic cosmic rays that come from outside the solar system . At that point, Voyager 1 was 11.25 billion miles (18.11 billion km) from the sun, or about 121 astronomical units (AU).

One AU is the average Earth-sun distance — about 93 million miles (150 million km).

You can keep tabs on the Voyager 1's current distance and mission status on this NASA website .

Since flying into interstellar space, Voyager 1 has sent back a variety of valuable information about conditions in this zone of the universe . Its discoveries include showing that cosmic radiation out there is very intense, and demonstrating how charged particles from the sun interact with those emitted by other stars , mission project scientist Ed Stone, of the California Institute of Technology in Pasadena, told Space.com in September 2017 .

The spacecraft's capabilities continue to astound engineers. In December 2017, for example, NASA announced that Voyager 1 successfully used its backup thrusters to orient itself to "talk" with Earth . The trajectory correction maneuver (TCM) thrusters hadn't been used since November 1980, during Voyager 1's flyby of Saturn. Since then, the spacecraft had primarily used its standard attitude-control thrusters to swing the spacecraft in the right orientation to communicate with Earth. 

As the performance of the attitude-control thrusters began to deteriorate, however, NASA decided to test the TCM thrusters — an idea that could extend Voyager 1's operational life. That test ultimately succeeded. 

"With these thrusters that are still functional after 37 years without use, we will be able to extend the life of the Voyager 1 spacecraft by two to three years," Voyager project manager Suzanne Dodd, of NASA's Jet Propulsion, Laboratory (JPL) in Southern California, said in a statement in December 2017 .

Mission team members have taken other measures to extend Voyager 1's life as well. For example, they turned off the spacecraft's cameras shortly after the Pale Blue Dot photo was taken to help conserve Voyager 1's limited power supply. (The cameras wouldn't pick up much in the darkness of deep space anyway.) Over the years, the mission team has turned off five other scientific instruments as well, leaving Voyager 1 with four that are still functioning — the Cosmic Ray Subsystem, the Low-Energy Charged Particles instrument, the Magnetometer and the Plasma Wave Subsystem. (Similar measures have been taken with Voyager 2, which currently has five operational instruments .)

The Voyager spacecraft each celebrated 45 years in space in 2022, a monumental milestone for the twin probes.

"Over the last 45 years, the Voyager missions have been integral in providing this knowledge and have helped change our understanding of the sun and its influence in ways no other spacecraft can," says Nicola Fox, director of the Heliophysics Division at NASA Headquarters in Washington, in a NASA statement .

"Today, as both Voyagers explore interstellar space, they are providing humanity with observations of uncharted territory," said Linda Spilker, Voyager's deputy project scientist at JPL in the same NASA statement.

"This is the first time we've been able to directly study how a star, our Sun, interacts with the particles and magnetic fields outside our heliosphere, helping scientists understand the local neighborhood between the stars, upending some of the theories about this region, and providing key information for future missions." Spilker continues.

Voyager 1's next big encounter will take place in 40,000 years when the probe comes within 1.7 light-years of the star AC +79 3888. (The star is roughly 17.5 light-years from Earth.) However, Voyager 1's falling power supply means it will probably stop collecting scientific data around 2025.

You can learn much more about both Voyagers' design, scientific instruments and mission goals at JPL's Voyager site . NASA has lots of in-depth information about the Pale Blue Dot photo, including Carl Sagan's large role in making it happen, here . And if you're interested in the Golden Record, check out this detailed New Yorker piece by Timothy Ferris, who produced the historic artifact.  Explore the history of Voyager with this interactive timeline courtesy of NASA.  

Bibliography

• Bell, Jim. " The Interstellar Age: Inside the Forty-Year Voyager Mission ," Dutton, 2015.
• Landau, Elizabeth. "The Voyagers in popular culture," Dec. 1, 2017. https://www.nasa.gov/feature/jpl/the-voyagers-in-popular-culture
• PBS, "Voyager: A history in photos." https://www.pbs.org/the-farthest/mission/voyager-history-photos/

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Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for Space.com for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, " Why Am I Taller ?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: https://qoto.org/@howellspace

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45 years ago: voyager 1 begins its epic journey to the outer planets and beyond, johnson space center.

Forty-five years ago, the Voyager 1 spacecraft began an epic journey that continues to this day. The second of a pair of spacecraft, Voyager 1 lifted off on Sept. 5, 1977, 16 days after its twin left on a similar voyage. NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, managed the two spacecraft on their missions to explore the outer planets. Taking advantage of a rare planetary alignment to use the gravity of one planet to redirect the spacecraft to the next, the Voyagers planned to use Jupiter’s gravity to send them on to explore Saturn and its large moon Titan. They carried sophisticated instruments to conduct their in-depth explorations of the giant planets. Both spacecraft continue to return data as they make their way out of our solar system and enter interstellar space.

In the 1960s, mission designers at JPL noted that the next occurrence of a once-every-175-year alignment of the outer planets would happen in the late 1970s. A spacecraft could take advantage of this opportunity to fly by Jupiter and use its gravity to bend its trajectory to visit Saturn, and repeat the process to also visit Uranus, Neptune, and Pluto. Launching several missions to visit each planet individually would take much longer and cost much more. The original plan to send two pairs of Thermoelectric Outer Planet Spacecraft on these Grand Tours proved too costly leading to its cancellation in 1971. The next year, NASA approved a scaled-down version of the project to send a pair of Mariner-class spacecraft in 1977 to explore just Jupiter and Saturn, with an expected five-year operational life. On March 7, 1977, NASA Administrator James C. Fletcher announced the renaming of these Mariner Jupiter/Saturn 1977 spacecraft as Voyager 1 and 2. Scientists held out hope that one of them could ultimately visit Uranus and Neptune, thereby fulfilling most of the original Grand Tour’s objectives – Pluto would have to wait several decades for its first visit.

Each Voyager carried a suite of 11 instruments to study the planets during each encounter and to learn more about interplanetary space in the outer reaches of the solar system, including: 

• An imaging science system consisting of narrow-angle and wide-angle cameras to photograph the planet and its satellites.
• A radio science system to determine the planet’s physical properties.
• An infrared interferometer spectrometer to investigate local and global energy balance and atmospheric composition.
• An ultraviolet spectrometer to measure atmospheric properties.
• A magnetometer to analyze the planet’s magnetic field and interaction with the solar wind.
• A plasma spectrometer to investigate microscopic properties of plasma ions.
• A low-energy charged particle device to measure fluxes and distributions of ions.
• A cosmic ray detection system to determine the origin and behavior of cosmic radiation.
• A planetary radio astronomy investigation to study radio emissions from Jupiter.
• A photopolarimeter to measure the planet’s surface composition.
• A plasma wave system to study the planet’s magnetosphere.

Voyager 1 lifted off on Sept. 5, 1977, atop a Titan IIIE-Centaur rocket from Launch Complex 41 at Cape Canaveral Air Force Station, now Cape Canaveral Space Force Station, in Florida. Two weeks after its launch, from a distance of 7.25 million miles, Voyager 1 turned its camera back toward its home planet and took the first single-frame image of the Earth-Moon system. The spacecraft successfully crossed the asteroid belt between Dec. 10, 1977, and Sept. 8, 1978.

Although Voyager 1 launched two weeks after its twin, it traveled on a faster trajectory and arrived at Jupiter four months earlier. Voyager 1 conducted its observations of Jupiter between Jan. 6 and April 13, 1979, making its closest approach of 216,837 miles from the planet’s center on March 5. The spacecraft returned 19,000 images of the giant planet, many of Jupiter’s satellites, and confirmed the presence of a thin ring encircling it. Its other instruments returned information about Jupiter’s atmosphere and magnetic field. Jupiter’s massive gravity field bent the spacecraft’s trajectory and accelerated it toward Saturn.

Voyager 1 began its long-range observations of Saturn on Aug. 22, 1980, passed within 114,500 miles of the planet’s center on Nov. 12, and concluded its studies on Dec. 14. Because of its interest to scientists, mission planners chose the spacecraft’s trajectory to make a close flyby of Saturn’s largest moon Titan – the only planetary satellite with a dense atmosphere – just before the closest approach to the planet itself. This trajectory, passing over Saturn’s south pole and bending north over the plane of the ecliptic, precluded Voyager 1 from making any additional planetary encounters. The spacecraft flew 4,033 miles from Titan’s center, returning images of its unbroken orange atmosphere and high-altitude blue haze layer. During the encounter, Voyager 1 returned 16,000 photographs, imaging Saturn, its rings, many of its known satellites and discovering several new ones, while its instruments returned data about Saturn’s atmosphere and magnetic field.

On Feb. 14, 1990, more than 12 years after it began its journey from Earth and shortly before controllers  permanently turned off its cameras to conserve power, Voyager 1 spun around and pointed them back into the solar system. In a mosaic of 60 images, it captured a “family portrait” of six of the solar system’s planets, including a pale blue dot called Earth more than 3.7 billion miles away. Fittingly, these were the last pictures returned from either Voyager spacecraft. On Feb. 17, 1998, Voyager 1 became the most distant human-made object, overtaking the Pioneer 10 spacecraft on their way out of the solar system. In February 2020, to commemorate the photograph’s 30th anniversary, NASA released a remastered version of the image of Earth as Pale Blue Dot Revisited .

On New Year’s Day 1990, both spacecraft officially began the Voyager Interstellar Mission as they inexorably made their escape from our solar system. On Aug. 25, 2012, Voyager 1 passed beyond the heliopause, the boundary between the heliosphere, the bubble-like region of space created by the Sun, and the interstellar medium. Its twin followed suit six years later. Today , 45 years after its launch and 14.6 billion miles from Earth, four of Voyager 1’s 11 instruments continue to return useful data, having now spent 10 years in interstellar space. Signals from the spacecraft take nearly 22 hours to reach Earth, and 22 hours for Earth-based signals to reach the spacecraft. Engineers expect that the spacecraft will continue to return data from interstellar space until about 2025 when it will no longer be able to power its systems. And just in case an alien intelligence finds it one day, Voyager 1 like its twin carries a gold-plated record that contains information about its home planet, including recordings of terrestrial sounds, music, and greetings in 55 languages. Engineers at NASA thoughtfully included Instructions on how to play the record.

The voyage continues…

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Good news from Voyager 1, which is now out past the edge of the solar system

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In mid-November, Voyager 1 suffered a glitch, and it's messages stopped making sense. But the NASA probe is once again sending messages to Earth that make sense.

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May 30, 2024

Voyager 1’s Revival Offers Inspiration for Everyone on Earth

Instruments may fail, but humanity’s most distant sentinel will keep exploring, and inspiring us all

By Saswato R. Das

Artist's rendering of a Voyager spacecraft in deep space.

Dotted Zebra/Alamy Stock Photo

Amid April’s litany of bad news—war in Gaza, protests on American campuses, an impasse in Ukraine—a little uplift came for science buffs.

NASA has reestablished touch with Voyager 1 , the most distant thing built by our species, now hurtling through interstellar space far beyond the orbit of Pluto. The extraordinarily durable spacecraft had stopped transmitting data in November, but NASA engineers managed a very clever work-around, and it is sending data again. Now more than 15 billion miles away, Voyager 1 is the farthest human object, and continues to speed away from us at approximately 38,000 miles per hour.

Like an old car that continues to run, or an uncle blessed with an uncommonly long life, the robotic spacecraft is a super ager that goes on and on—and, in doing so, has captivated space buffs everywhere.

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Launched on September 5, 1977, the one-ton Voyager 1 was meant to chart the outer solar system, in particular the gas giant planets Jupiter and Saturn, and Saturn’s moon, Titan. Its twin, Voyager 2 , launched the same year, followed a different trajectory with a slightly different mission to explore the outer planets before heading to the solar system’s edge.

Those were NASA’s glory days. A few years earlier, NASA had successfully landed men on the moon—and won the space race for the U.S. NASA’s engineers were the envy of the world.

To get to Jupiter and Saturn, both Voyagers had to traverse the asteroid belt, which is full of rocks and debris orbiting the sun. They had to survive cosmic rays, intense radiation from Jupiter and other perils of space. But the two spacecraft made it without a hitch.

President Jimmy Carter held office when Voyager 1 was launched from Cape Canaveral; Elvis Presley had died just three weeks before; gas was about 60 cents a gallon; and, like now, the Middle East was in crisis, with Israeli Prime Minister Menachem Begin and Egyptian President Anwar Sadat trying to find peace.

Voyager 1 sent back spectacular photos of Jupiter and its giant red spot. It showed how dynamic the Jovian atmosphere was, with clouds and storms. It also took pictures of Jupiter’s moon Io, with its volcanoes, and Saturn’s moon Titan , which astronomers think has an atmosphere similar to the primordial Earth’s. The spacecraft discovered a thin ring around Jupiter and two new Jovian moons, which were named Thebe and Metis. On reaching Saturn, it discovered five new moons as well as a new ring.

And then Voyager 1 continued on its journey and sent images back from the edge of the solar system. Many of us remember the Pale Blue Dot , a haunting picture of the Earth it took on Feb 14, 1990, when it was a distance of 3.7 billion miles from the sun. The astronomer Carl Sagan wrote:

“There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.”

By then Voyager 1 had long outlived its planetary mission but kept faithfully calling home as it traveled beyond the solar system into the realm of the stars. By 2012 Voyager 1 had reached the heliosphere , the farthest edge of the solar system. There, it penetrated the heliopause, where the solar wind ends, stopped by particles coming from the interstellar medium, the vast space between the stars. (Astronomers know that the space between the stars is not totally empty but permeated by a rarefied gas .)

From Voyager 1, scientists learned that the heliopause is quite dynamic and first measured the magnetic field of the Milky Way beyond the solar system. And its instruments kept sending data as it traveled through the interstellar medium.

On hearing that Voyager 1 had gone dark, I had checked in with Louis Lanzerotti , a former Bell Labs planetary scientist who did the calibrations for the Voyager 1 spacecraft and was a principal investigator on many experiments. He told me that a NASA manager in the 1970s had doubted that the spacecraft’s mechanical scan platform, which pointed instruments at targets, and very thin solid state detectors, which took those edge of the solar system readings, on the spacecraft would survive. They not only survived but worked flawlessly for all this time, Lanzerotti said, providing excellent data for decades. He was overjoyed on hearing the news that Voyager 1 was still alive.

Voyager 1 instruments have power until 2025 . After that, they will shut off, one by one. But there is nothing to stop the spacecraft as it speeds away from us in the vast emptiness of space.

Thousands of years from now, maybe when the human race has left this planet, Voyager 1, the tiny little spacecraft that could, will still continue its inexorable journey to the stars.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.

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AGU: Voyager 1 has left the solar system, sudden changes in cosmic rays indicate

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“Within just a few days, the heliospheric intensity of trapped radiation decreased, and the cosmic ray intensity went up as you would expect if it exited the heliosphere,” said Bill Webber, professor emeritus of astronomy at New Mexico State University in Las Cruces. He calls this transition boundary the “heliocliff.”

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Voyager 1 sends strange signals from beyond the solar system. Scientists are confused.

Spending 45 years traversing the solar system really does a number on a spacecraft.

NASA's Voyager 1 mission launched in 1977, passed into what scientists call interstellar space in 2012 and just kept going — the spacecraft is now 14.5 billion miles (23.3 billion kilometers) away from Earth . And while Voyager 1 is still operating properly, scientists on the mission recently noticed that it appeared confused about its location in space without going into safe mode or otherwise sounding an alarm.

"A mystery like this is sort of par for the course at this stage of the Voyager mission," Suzanne Dodd, project manager for Voyager 1 and its twin, Voyager 2, at NASA's Jet Propulsion Laboratory in California, said in a statement .

Related : Pale Blue Dot at 30: Voyager 1's iconic photo of Earth from space reveals our place in the universe

"The spacecraft are both almost 45 years old, which is far beyond what the mission planners anticipated," Dodd added. "We're also in interstellar space — a high-radiation environment that no spacecraft have flown in before."

The glitch has to do with Voyager 1's attitude articulation and control system, or AACS, which keeps the spacecraft and its antenna in the proper orientation. And the AACS seems to be working just fine, since the spacecraft is receiving commands, acting on them and sending science data back to Earth with the same signal strength as usual. Nevertheless, the AACS is sending the spacecraft's handlers junk telemetry data.

The NASA statement does not specify when the issue began or how long it has lasted.

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The agency says that Voyager personnel will continue to investigate the issue and attempt to either fix or adapt to it. That's a slow process, since a signal from Earth currently takes 20 hours and 33 minutes to reach Voyager 1; receiving the spacecraft's response carries the same delay.

— What Voyager 1 learned at Jupiter 40 years ago — Voyager at 40: 40 photos from NASA's epic 'grand tour' mission — Voyager 1's historic flyby of Jupiter in photos  

The twin Voyager 2 probe, also launched in 1977, is behaving normally, NASA said. The power the twin spacecraft can produce is always falling, and mission team members have turned some components off to save juice — measures they hope will keep the probes working through at least 2025.

"There are some big challenges for the engineering team," Dodd said. "But I think if there's a way to solve this issue with the AACS, our team will find it."

Email Meghan Bartels at [email protected] or follow her on Twitter @ meghanbartels . Follow us on Twitter @ Spacedotcom and on Facebook .

Meghan is a senior writer at Space.com and has more than five years' experience as a science journalist based in New York City. She joined Space.com in July 2018, with previous writing published in outlets including Newsweek and Audubon. Meghan earned an MA in science journalism from New York University and a BA in classics from Georgetown University, and in her free time she enjoys reading and visiting museums. Follow her on Twitter at @meghanbartels.

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NASA's Voyager 1 spacecraft is talking nonsense. Its friends on Earth are worried

The last time Stamatios "Tom" Krimigis saw the Voyager 1 space probe in person, it was the summer of 1977, just before it launched from Cape Canaveral, Florida.

Now Voyager 1 is over 15 billion miles away, beyond what many consider to be the edge of the solar system. Yet the on-board instrument Krimigis is in charge of is still going strong.

"I am the most surprised person in the world," says Krimigis — after all, the spacecraft's original mission to Jupiter and Saturn was only supposed to last about four years.

These days, though, he's also feeling another emotion when he thinks of Voyager 1.

"Frankly, I'm very worried," he says.

Ever since mid-November, the Voyager 1 spacecraft has been sending messages back to Earth that don't make any sense. It's as if the aging spacecraft has suffered some kind of stroke that's interfering with its ability to speak.

"It basically stopped talking to us in a coherent manner," says Suzanne Dodd of NASA's Jet Propulsion Laboratory, who has been the project manager for the Voyager interstellar mission since 2010. "It's a serious problem."

Instead of sending messages home in binary code, Voyager 1 is now just sending back alternating 1s and 0s. Dodd's team has tried the usual tricks to reset things — with no luck.

It looks like there's a problem with the onboard computer that takes data and packages it up to send back home. All of this computer technology is primitive compared to, say, the key fob that unlocks your car, says Dodd.

"The button you press to open the door of your car, that has more compute power than the Voyager spacecrafts do," she says. "It's remarkable that they keep flying, and that they've flown for 46-plus years."

Voyager 1 and its twin, Voyager 2, have outlasted many of those who designed and built them. So to try to fix Voyager 1's current woes, the dozen or so people on Dodd's team have had to pore over yellowed documents and old mimeographs.

"They're doing a lot of work to try and get into the heads of the original developers and figure out why they designed something the way they did and what we could possibly try that might give us some answers to what's going wrong with the spacecraft," says Dodd.

She says that they do have a list of possible fixes. As time goes on, they'll likely start sending commands to Voyager 1 that are more bold and risky.

"The things that we will do going forward are probably more challenging in the sense that you can't tell exactly if it's going to execute correctly — or if you're going to maybe do something you didn't want to do, inadvertently," says Dodd.

Linda Spilker , who serves as the Voyager mission's project scientist at NASA's Jet Propulsion Laboratory, says that when she comes to work she sees "all of these circuit diagrams up on the wall with sticky notes attached. And these people are just having a great time trying to troubleshoot, you know, the 60's and 70's technology."

"I'm cautiously optimistic," she says. "There's a lot of creativity there."

Still, this is a painstaking process that could take weeks, or even months. Voyager 1 is so distant, it takes almost a whole day for a signal to travel out there, and then a whole day for its response to return.

"We'll keep trying," says Dodd, "and it won't be quick."

In the meantime, Voyager's 1 discombobulation is a bummer for researchers like Stella Ocker , an astronomer with Caltech and the Carnegie Observatories

"We haven't been getting science data since this anomaly started," says Ocker, "and what that means is that we don't know what the environment that the spacecraft is traveling through looks like."

That interstellar environment isn't just empty darkness, she says. It contains stuff like gas, dust, and cosmic rays. Only the twin Voyager probes are far out enough to sample this cosmic stew.

"The science that I'm really interested in doing is actually only possible with Voyager 1," says Ocker, because Voyager 2 — despite being generally healthy for its advanced age — can't take the particular measurements she needs for her research.

Even if NASA's experts and consultants somehow come up with a miraculous plan that can get Voyager 1 back to normal, its time is running out.

The two Voyager probes are powered by plutonium, but that power system will eventually run out of juice. Mission managers have turned off heaters and taken other measures to conserve power and extend the Voyager probes' lifespan.

"My motto for a long time was 50 years or bust," says Krimigis with a laugh, "but we're sort of approaching that."

In a couple of years, the ebbing power supply will force managers to start turning off science instruments, one by one. The very last instrument might keep going until around 2030 or so.

When the power runs out and the probes are lifeless, Krimigis says both of these legendary space probes will basically become "space junk."

"It pains me to say that," he says. While Krimigis has participated in space missions to every planet, he says the Voyager program has a special place in his heart.

Spilker points out that each spacecraft will keep moving outward, carrying its copy of a golden record that has recorded greetings in many languages, along with the sounds of Earth.

"The science mission will end. But a part of Voyager and a part of us will continue on in the space between the stars," says Spilker, noting that the golden records "may even outlast humanity as we know it."

Krimigis, though, doubts that any alien will ever stumble across a Voyager probe and have a listen.

"Space is empty," he says, "and the probability of Voyager ever running into a planet is probably slim to none."

It will take about 40,000 years for Voyager 1 to approach another star; it will come within 1.7 light years of what NASA calls "an obscure star in the constellation Ursa Minor" — also known as the Little Dipper.

Knowing that the Voyager probes are running out of time, scientists have been drawing up plans for a new mission that, if funded and launched by NASA, would send another probe even farther out into the space between stars.

"If it happens, it would launch in the 2030s," says Ocker, "and it would reach twice as far as Voyager 1 in just 50 years."

Copyright 2024 NPR. To see more, visit https://www.npr.org.

How astronomers work out the size of the Solar System

Post Doctoral Research Fellow in Space Science, University of Birmingham

Disclosure statement

Gareth Dorrian does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

University of Birmingham provides funding as a founding partner of The Conversation UK.

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The size of the solar system is defined by the volume of space over which the Sun’s influence exceeds those of other nearby stars in the Milky Way galaxy. This influence derives from two fundamental forces of nature: gravity and magnetism.

Let’s tackle gravity first . Every object in the solar system experiences a gravitational pull from the Sun; the farther away one is from the Sun, the weaker the pull. Provided, however, that the Sun’s gravity is still stronger at your position in space than the gravity from any other stars, then your motion through space will be subject to an acceleration which pulls you towards the Sun.

At this point, it is useful to introduce a more convenient unit of measurement for distance: the astronomical unit (AU). A distance of 1 AU is the distance between the Sun and Earth, which is approximately 150 million km. All of the known planets, asteroids, and almost all of the known comets are gravitationally bound to the Sun and orbit around it. More distant objects experiencing a weaker gravitational pull, take longer to complete an orbit.

The Earth, at 1 AU of course, takes one year. Jupiter, orbiting the Sun at 5 AU, takes just under 12 years. Distant Pluto (about 40 AU) takes 248 years –- so long in fact, that it hasn’t even completed one orbit of the Sun since it was discovered in 1930. Pluto, however, is far from being at the edge of the Solar System; there are many more distant worlds.

The most distant gravitationally bound objects to the Sun are aperiodic comets. Aperiodic, or long-period comets, can take many thousands of years to complete one solar orbit. All of them have completed no more than a single passage through the inner solar system during recorded history.

These comets are believed to come from the Oort Cloud ; a roughly spherical cloud made up of billions of small icy worlds. These drift through the frigid outermost reaches of the Solar System at distances of up to 200,000 AU (approximately 3 Light Years).

An Oort Cloud object may take millions of years to orbit the Sun once at such vast distances. Objects which stray farther from the Sun than this are likely to experience stronger gravitational pulls from other stars, and begin to accelerate towards those instead.

Oort Cloud objects are so far away that none has been seen in situ by even our most powerful telescopes. The only time we get to see them is when one happens to fall towards the inner solar system, as a comet.

We’ve heard about gravity, but what about that other force: magnetism? In addition to a powerful gravitational field, the Sun possesses a very strong magnetic field, which carves out a volume of space called the heliosphere , within which lie all the planets and the extended atmosphere of the Sun, called the solar wind . The solar wind is a continuous supersonic outflow of plasma from the Sun into interplanetary space.

The solar wind is highly dynamic and when interacting with the atmosphere of a planet like the Earth it can generate colourful displays of aurora such as those we saw recently . The solar wind flows outwards from the Sun, past all the known planets, before finally slowing down and becoming subsonic (slower than the speed of sound) when it reaches the heliopause .

The distance to the heliopause is much closer to the Sun than the Oort Cloud. Nevertheless, it is still enormous. Having launched in 1977 the Nasa spacecraft Voyager 1 crossed the heliopause, at a distance of 121 AU, in 2012, becoming the first human built object to reach interstellar space .

Had Voyager 1 been launched by our evolutionary ancestors a few million years ago, however, the journey to the heliopause might not have taken quite so long. The space between the stars is not empty, but is filled with tenuous clouds of gas and dust called the interstellar medium. Sometimes, the orbit of a star around the centre of the Milky Way galaxy may carry it through unusually dense regions of material.

In a recent study , scientists have demonstrated a high likelihood that about 2-3 million years ago, the solar system passed through a relatively dense cloud of cold interstellar gas which could have compressed the heliosphere down to a size of just 0.2 AU which is entirely within the orbit of Mercury - the nearest planet to the Sun and, arguably , the Earth. This would have directly exposed all of the planets to the environment of interstellar space.

Among the potential impacts on Earth were a substantial increase in cosmic rays reaching our planet, no aurora (because the solar wind could not reach the Earth), and a more changeable climate which may even have influenced the evolution of our species.

• Solar system

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Quick Facts

Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year

Voyager 2 is escaping the solar system at a speed of about 3.1 AU per year

Five spacecraft - Voyagers 1 and 2; Pioneers 10 and 11; and New Horizons are on an interstellar trajectory.

Voyager's computers procees about 8,000 instructions per section. A modern smartphone yields more than 14 billion instructions per second.

Can the Voyager imaging cameras be turned back on?

It is possible for the cameras to be turned on, but it is not a priority for Voyager's Interstellar Mission. After Voyager 1 took its last image (the "Solar System Family Portrait" in 1990), the cameras were turned off to save power and memory for the instruments expected to detect the new charged particle environment of interstellar space. Mission managers removed the software from both spacecraft that controls the camera. The computers on the ground that understand the software and analyze the images do not exist anymore. The cameras and their heaters have also been exposed for years to the very cold conditions at the deep reaches of our solar system. Even if mission managers recreated the computers on the ground, reloaded the software onto the spacecraft and were able to turn the cameras back on, it is not clear that they would work.

In addition, it is very dark where the Voyagers are now. While you could still see some brighter stars and some of the planets with the cameras, you can actually see these stars and planets better with amateur telescopes on Earth.

What instruments on the spacecraft are still working and what have been turned off?

View an updated list of the status o/f Voyager instruments: Mission Status .

How long can Voyager 1 and 2 continue to function?

Editor's note: Both Voyagers were still functioning in January 2024.

The radioisotope thermoelectric generator (RTG) on each spacecraft puts out 4 watts less each year. Because of this diminishing electrical power, the Voyager team has had to prioritize which instruments to keep on and which to turn off. Heaters and other systems have also been turned off one by one as part of power management.

The Voyager team has chosen to keep operating the instruments that are the most likely to send back key data about the heliosphere and interstellar space -- the fields and particles instruments. Engineers expect to begin turning off fields and particles science instruments one by one, starting in 2020 for Voyager 2. Voyager 2 will have to start turning science instruments off sooner because it is currently operating one more instrument than Voyager 1. Engineers expect each spacecraft to continue operating at least one science instrument until around 2025.

Even if science data won't likely be collected after 2025, engineering data could continue to be returned for several more years. The two Voyager spacecraft could remain in the range of the Deep Space Network through about 2036, depending on how much power the spacecraft still have to transmit a signal back to Earth.

Where are Voyager 1 and 2 today?

Where is Voyager 1 going? When will it get there? How about Voyager 2?

Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year, 35 degrees out of the ecliptic plane to the north, in the general direction of the solar apex (the direction of the sun's motion relative to nearby stars). Voyager 1 will leave the solar system aiming toward the constellation Ophiuchus. In the year 40,272 AD (more than 38,200 years from now), Voyager 1 will come within 1.7 light years of an obscure star in the constellation Ursa Minor (the Little Bear or Little Dipper) called AC+79 3888.

Voyager 2 is escaping the solar system at a speed of about 3.1 AU per year, 48 degrees out of the ecliptic plane to the south toward the constellations of Sagittarius and Pavo. In about 40,000 years, Voyager 2 will come within about 1.7 light years of a star called Ross 248, a small star in the constellation of Andromeda..

Where do we consider our solar system to end; Pluto's orbit? Solar apex?

The solar system may be broadly defined as consisting of all those objects that are ultimately governed by the gravitational field of the sun. In addition to the planets, moons, asteroids and dust of the planetary system, it includes the distant bodies of the Kuiper Belt and Oort cloud, the last extending perhaps as far as 50,000 astronomical units (1 AU = about 93 million miles). The gravitational influence of the sun may extend as far as 2 light years. (From "Solar System", James H. Shirley, in Encyclopedia of Planetary Science).

That said, Pluto (and sometimes Neptune) is the most distant planet in our planetary system. The Voyagers passed the orbit of Neptune (which was furthest at the time) in August 1989. Neither flew by Pluto, which was elsewhere in its orbit at the time.

Another concept is the heliosphere, which is a bubble around the sun created by the outward flow of the solar wind from the sun and the opposing inward flow of the interstellar wind. That heliosphere is the region influenced by the dynamic properties of the sun that are carried in the solar wind - such as magnetic fields, energetic particles, solar wind plasma, etc. Voyager 1, which is traveling up away from the plane of the planets, passed out of the heliosphere into interstellar space, beyond the bubble of the solar wind, on Aug. 25, 2012. Voyager 2, which is traveling below the plane of the planets, is expected to enter interstellar space in the coming years.

Have any human-made objects ever exited the solar system?

Sometimes, it is written that Voyager and Pioneers 10 and 11 have exited the solar system. Though all of these spacecraft have gone beyond all the planets of the solar system, they have not exited the solar system, based on the scientific definition. To leave the solar system, they need to pass beyond the Oort Cloud. Voyager 1 was the first-ever object to reach interstellar space on August 25, 2012 when it passed beyond the sun’s realm of plasma influence (the heliosphere) and it is the most distant human-made object. But it will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Voyager 2 has not yet reached interstellar space or exited the heliosphere (bubble of solar plasma). Pioneer 10 and 11 are no longer transmitting science data back to Earth.

Are the distance counters rolling backwards?

Often they are, and it's actually not an error. This is caused by the fact that Earth moves around the sun more quickly than either Voyager spacecraft is departing from Earth. So, at certain times of the year, the distance between Earth and each Voyager actually decreases.

Did either of the Voyagers visit Pluto? Why didn't the Voyagers fly by Pluto?

Both Voyagers flew beyond the orbit of Pluto/Neptune in 1989, but neither flew by Pluto, which was elsewhere in its orbit at the time. It was never planned that the Voyagers would visit Pluto.

The original mission of Voyager was to explore Jupiter and Saturn. Two spacecraft were sent on slightly different paths, first to Jupiter and then, with gravity assists, on to Saturn. Voyager 1 could have been aimed on to Pluto, but exploration of Titan and the rings of Saturn was a primary scientific objective. This caused the trajectory to be diverted upward out of the ecliptic plane such that no further planetary encounters were possible for Voyager 1. Once Voyager 1 had successfully gathered data at Titan, Voyager 2 was allowed to go on to Uranus and Neptune. Voyager 2, theoretically, could have been aimed for Pluto, but the aim point would have been inside the planet of Neptune - not very practical. NASA's New Horizons spacecraft visited Pluto in July 2015.

When we send spacecraft through the asteroid belt to the outer planets, how do we navigate the craft through the belt?

Pioneers 10 and 11 had preceded the Voyagers to Jupiter and the asteroid belt was a major concern for them. By the 1960's more than 3000 minor planets had been discovered and their orbits well determined. Even 50,000 minor bodies spread over the volume of space occupied by the asteroid belt would produce little direct danger, although a chance collision with an uncatalogued object was possible.

"While the largest of the asteroids were known and their orbits charted, many of the asteroids moved in unknown orbits. Although the risk of a spacecraft colliding with a charted asteroid was negligible, there was no way to estimate how many particles the size of a grain of sand might be present in the asteroid belt to collide with the spacecraft and seriously damage it". (From Pioneer, First to Jupiter, Saturn and Beyond, NASA SP-446, 1980) Only by going there could the danger be properly assessed - and Pioneer was first.

I was reading Dr. Carl Sagan's biography recently and found that he persuaded NASA administrators to turn one of the Voyager space probes around in order to take a last image of the solar system. Is this true? Do the craft send back any images of where they are?

I think you are referring to the series of photos taken by Voyager 1 on Valentine's Day 1990. These were the final images taken by either of the Voyager spacecraft.

On Feb. 14, 1990, after the spacecraft had passed the orbits of Neptune and Pluto, the cameras of Voyager 1 pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever 'portrait' of our solar system as seen from the outside.

I can not locate a copy of the Murmurs of Earth CD. Would you know of a vendor that might sell copies of it?

There was a book and CDROM published by Warner New Media in 1992. The book was a reprint of the Carl Sagan, et al, "Murmurs of Earth" that was originally published in 1978.

Carl Sagan and his colleagues did the assemblage of the information on the Voyager Golden Phonograph Record. Most of the material they used was copyrighted by the creators/owners and Sagan had to get copyright releases in order to assemble the original record. Subsequently, Warner Multimedia was able to obtain copyright releases for the 1992 version of "Murmurs of Earth", by Carl Sagan, et al and included all the sounds and songs on the CDROM set that accompanied the Warner New Media release of the book. We have included on the Voyager web site only that information for which we were able to get release, that's why everything, especially the music and the photos, is not there.

Unfortunately, the book and CDROM are no longer being published and are hard to find as a set. Your best bet to find one quickly may be in a public or university library or at a used bookstore. You might try used bookstores on line at http://www.bookfinder.com/ and search on: Author: Carl Sagan Title: Murmurs of Earth

You can find many instances where the book is for sale at prices around $40 US or less (most less than $20), but few (if any) include the CDROM. Look for availability of 1992 or later versions.

If there is intelligent life in our universe and they were not a peace loving species, wouldn't the information on the Voyager be enough to destroy human kind?

We have received almost nothing but praise for the inclusion of the Golden Phonograph Record on Voyager. We have also received lots of compliments on the contents, however, that praise rightly belongs to Carl Sagan and his colleagues who chose, assembled and got permission to use the material.

There were a few detractors, even as Sagan was formulating the disk.

In the Sagan, et al book, "Murmurs of Earth, the Voyager Interstellar Record", while describing some of his earlier work in sending messages from the Arecibo radar, spoke of two protests to that effort. Excerpts from that passage follow:

"One was from a few scientists who worried that we hadn't corrected for the speed of Earth in space in launching the message. ...............The other protest was a serious one, made by Sir Martin Ryle, a Nobel laureate and the Astronomer Royal of England. He wrote with great anxiety that he felt it was very hazardous to reveal our existence and location to the galaxy. For all we know, any creatures out there were malevolent or hungry, and once they knew of us, the might come to attack or eat us...........Many other less knowledgeable people had the same concerns.

"The fact is, for better or for worse, we have already announced our presence and location to the universe, and continue to do so every day. There is a sphere of radio transmission about thirty light years thick expanding outward at the speed of light, announcing to every star it envelops that the earth is full of people. Our television programs flood space with signals detectable at enormous distances by instruments not much greater than our own. It is a sobering thought that the first news of us may be the outcome of the Super Bowl.

"........... Whether or not Sir Martin Ryle is justified in his anxieties about revealing the location of our civilization is of course a debatable subject. Even so, it is too late to worry about it, so we might as well try to be friendly".

What were the most important discoveries of the Voyager space probes?

There are so many. Voyager is probably the most scientifically productive mission ever. It was only the second mission to visit Jupiter and Saturn and the only one to visit Uranus and Neptune. Voyager 1 and 2 obtained the first detailed profiles of the atmospheres of Saturn, Uranus and Neptune and improved our understanding of the characteristics of the atmosphere of Jupiter. The Voyager spacecraft revealed the enormous amount of detail in the rings of Saturn, discovered the rings of Jupiter and provided the first detailed images of the rings of Uranus and Neptune. Voyager imaged Earth's moon and discovered twenty-three new moons at the outer planets. Voyager made significant improvements in the measurements of the magnetospheres at Jupiter and Saturn and provided the first measurements of the magnetospheres at Uranus and Neptune. The significance of the Voyager is the vast amount of new knowledge about our outer solar system it provided and the interest in further exploration it generated. That interest has resulted in the Galileo mission to Jupiter and the Cassini mission to Saturn as well as the discovery of three new satellites at Saturn using Earth-based instruments.

Discovery of active volcanism on Io, a satellite of Jupiter, was probably the greatest surprise. It was the first time active volcanoes had been seen on another body in the solar system. It appears that activity on Io affects the entire Jovian system.

How big is Voyager? How much does it weigh?

The Voyager spacecraft weight, including hydrazine, at launch was 815 kg or about 1797 pounds. It was almost the weight and size of a sub-compact car. The current approximate weight of Voyager 1 is 733 kg and Voyager 2 is 735 kg. The difference is in the amount of hydrazine remaining. Hydrazine is being used to control the spacecrafts' attitude.

The spacecraft, without the various booms could fit inside a cube that is about 4 meters on each side. The approximate measurements of the different structures follow:

• The high gain antenna is 3.7 meters across (diameter).
• The magnetometer boom is 13 meters long
• The two Planetary Radio Astronomy and Plasma Wave antenna are 10 meters long.
• The Radioisotope Thermoelectric Generator boom is 3.7 meters long
• The science instrument boom (near top of picture) is 3 meters long.
• The Bus Housing Electronics is about 1.8 meters in diameter.

The spacecraft height - from the top of the reflector structure in the middle of the high gain antenna to the bottom of the triangular feet below the bus housing electronics - is about 3.8 meters

The launch vehicle was a Titan III E/ Centaur rocket, which stands nearly 50 m (164 ft) high and weighs almost 635,000 kg (1.4 million lb).

Is it true that a sketch by Da Vinci is included in the "Message to the Universe" of Voyagers 1 and 2?

There are messages on the Voyagers in the form of a phonograph record and drawings on the cover that protects the record. However, Leonardo Da Vinci's Vitruvian Man was not part of the Voyager Golden Phonograph Record, the Voyager cover, or the Pioneer plaque. Read more about the golden record .

What kind of computers are used on the Voyager spacecraft?

There are three different computer types on the Voyager spacecraft and there are two of each kind. Total number of words among the six computers is about 32K.

• Computer Command System (CCS) - 18-bit word, interrupt type processors (2) with 4096 words each of plated wire, non-volatile memory.
• Flight Data System (FDS) - 16-bit word machine (2) with modular memories and 8198 words each
• Attitude and Articulation Control System (AACS) - 18-bit word machines (2) with 4096 words each.

According to my calculations, that's a total of about 68KB, or small potatoes compared to today's microprocessors. We probably could perform all functions with one of today's boards and still have room for solid state data storage and much more fault detection software. We would still need a second unit for redundancy. Today's microprocessors are also much faster than the chips used on Voyager and a comparative system would use less electrical power. On the other hand, software might be more complicated as opposed to that used in an interrupt type system, but it would be much more capable and more flexible.

Let's look closer at the CCS. The CCS has two main functions: to carry out instructions from the ground to operate the spacecraft, and to be alert for a problem or malfunction and respond to it. Two identical 4096- word memories contain both fixed routines (about 2800 words) and a variable section (about 1290 words) for changing science sequences. The CCS issues commands to the AACS for movement of the scan platform or spacecraft maneuvers; to the FDS for changes in instrument configurations or telemetry rates and to numerous other subsystems within the spacecraft for specific actions. Fault-protection algorithms are also stored in the CCS, occupying roughly 10 percent of the CCS memory.

The main functions of the FDS are to collect data from, and controls the operations of, the scientific instruments; and to format engineering and science data for on-board storage and/or real-time transmission. The FDS also keeps the spacecraft "time" and provides frequency references to the instruments and other spacecraft subsystems.

The Voyager spacecraft computers are interrupt driven computer, similar to processors used in general purpose computers with a few special instructions for increased efficiency. The programming is a form of assembly language.

There is no clock chip, as such, in the spacecraft. The "clock" is really a counter, based on one of several electronically generated frequencies. These frequencies, based on a reference, generated by a very stable oscillator, are converted and fed to different locations in the spacecraft as synchronization signals, timers, counters, etc. The "clock" signal is part of the information telemetered to the ground and it is with ground software that we convert to day of year, time of day Greenwich Mean Time.

Voyager was built in-house at JPL; the computers were manufactured by General Electric to JPL specifications.

How fast are the Voyager computers?

Not very fast compared to today’s standards. The master clock runs at 4 MHz but the CPU’s clock runs at only 250 KHz. A typical instruction takes 80 microseconds, that is about 8,000 instructions per second. To put this in perspective, a 2013 top-of-the-line smartphone runs at 1.5 GHz with four or more processors yielding over 14 billion instructions per second.

What is the "direction" (constellation and/or star) both Voyager 1 & 2 and the Pioneers are "aimed" for, at present.

• Pioneer 10 is headed towards the constellation of Taurus (The Bull). It will take Pioneer over 2 million years to pass by one of the stars in the constellation.
• Pioneer 11 is headed toward the constellation of Aquila (The Eagle), Northwest of the constellation of Sagittarius. Pioneer 11 may pass near one of the stars in the constellation in about 4 million years.
• Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year, 35 degrees out of the ecliptic plane to the north, in the general direction of the Solar Apex (the direction of the Sun's motion relative to nearby stars). Voyager 1 will leave the solar system aiming toward the constellation Ophiuchus. In the year 40,272 AD, Voyager 1 will come within 1.7 light years of an obscure star in the constellation Ursa Minor (the Little Bear or Little Dipper) called AC+79 3888.
• Voyager 2 is also escaping the solar system at a speed of about 3.1 AU per year, 48 degrees out of the ecliptic plane to the south toward the constellations of Sagitarrius and Pavo. In about 40,000 years, Voyager 2 will come within about 1.7 light years of a star called Ross 248, a small star in the constellation of Andromeda.

Where can I find pictures of what the Voyager spacecraft took?

You can view pictures from Voyager and other missions at several locations:

• NSSDC Planetary Image Catalog http://nssdc.gsfc.nasa.gov/imgcat
• Planetary Photojournal http://photojournal.jpl.nasa.gov/
• NSSDC Photo Gallery http://nssdc.gsfc.nasa.gov/photo_gallery

Is there some sort of plate with pictograms on the Voyager 1 spacecraft? Also is it similar to the Pioneer spacecraft plaque?

You asked about the Voyager plate. I'm assuming you mean the engravings on the aluminum record cover on each of the two Voyagers. You can see the record cover installed on the spacecraft bus . Also, from Carl Sagan's book, "Murmurs of Earth", here is a description of the cover engravings:

"In the upper left-hand corner is an easily recognized drawing of the phonograph record and the stylus carried with it. The stylus is in the correct position to play the record from the beginning. Written around it in binary arithmetic is the correct time of one rotation of the record, 3.6 seconds, expressed in time units of 0,70 billionths of a second, the time period associated with a fundamental transition of the hydrogen atom. The drawing indicates that the record should be played from the outside in. Below this drawing is a side view of the record and stylus, with a binary number giving the time to play one side of the record - about an hour.

"The information in the upper right-hand portion of the cover is designed to show how pictures are to be constructed from the recorded signals. The top drawing shows the typical signal that occurs at the start of a picture. The picture is made from this signal, which traces the picture as a series of vertical lines, similar to ordinary television (in which the picture is a series of horizontal lines). Picture lines 1, 2 and 3 are noted in binary numbers, and the duration of one of the "picture lines," about 8 milliseconds, is noted. The drawing immediately below shows how these lines are to be drawn vertically, with staggered "interlace" to give the correct picture rendition. Immediately below this is a drawing of an entire picture raster, showing that there are 512 vertical lines in a complete picture. Immediately below this is a replica of the first picture on the record to permit the recipients to verify that they are decoding the signals correctly. A circle was used in this picture to insure that the recipients use the correct ratio of horizontal to vertical height in picture reconstruction.

"The drawing in the lower left-hand corner of the cover is the pulsar map previously sent as part of the plaques on Pioneers 10 and 11. It shows the location of the solar system with respect to 14 pulsars, whose precise periods are given. The drawing containing two circles in the lower right-hand corner is a drawing of the hydrogen atom in its two lowest states, with a connecting line and digit 1 to indicate that the time interval associated with the transition from one state to the other is to be used as the fundamental time scale, both for the time given on the cover and in the decoded pictures.

"Electroplated onto the record's cover is an ultra-pure source of uranium-238 with a radioactivity of about 0.00026 microcuries. The steady decay of the uranium source into its daughter isotopes makes it a kind of radioactive clock. Half of the uranium-238 will decay in 4.51 billion years. Thus, by examining this two-centimeter diameter area on the record plate and measuring the amount of daughter elements to the remaining uranium-238, an extraterrestrial recipient of the Voyager spacecraft could calculate the time elapsed since a spot of uranium was placed aboard the spacecraft. This should be a check on the epoch of launch, which is also described by the pulsar map on the record cover."

🔭 Never-before-seen ices detected in the solar system

Full original reading on Techno-Science

Trans-Neptunian Objects (TNOs) refer to the primitive small bodies in the outer regions of our Solar System, orbiting beyond Neptune. Formed quite far from the Sun, these objects still hold valuable information about their formation over 4 billion years ago, unlike dwarf planets such as Pluto which may have undergone significant internal evolution.

TNOs have also witnessed planetary migration processes that have redistributed most of them far from their formation regions. To date, observations of TNOs have been limited, providing only a partial characterization of their chemical composition: only water and methanol ices were detected on a handful of objects.

A major observation program by the James Webb Space Telescope recently provided the first comprehensive view of TNOs. The observations of 59 objects obtained with the NIRSpec instrument were analyzed by an international research team involving scientists from CNRS Earth & Universe. The infrared spectra reveal the very first detections of CO 2 and CO ices on small bodies in the outer Solar... read more ⯈

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Galleries of Images Voyager Took

The Voyager 1 and 2 spacecraft explored Jupiter, Saturn, Uranus and Neptune before starting their journey toward interstellar space. Here you'll find some of those iconic images, including "The Pale Blue Dot" - famously described by Carl Sagan - and what are still the only up-close images of Uranus and Neptune.

Photography of Jupiter began in January 1979, when images of the brightly banded planet already exceeded the best taken from Earth. Voyager 1 completed its Jupiter encounter in early April, after taking almost 19,000 pictures and many other scientific measurements. Voyager 2 picked up the baton in late April and its encounter continued into August. They took more than 33,000 pictures of Jupiter and its five major satellites.

The Voyager 1 and 2 Saturn encounters occurred nine months apart, in November 1980 and August 1981. Voyager 1 is leaving the solar system. Voyager 2 completed its encounter with Uranus in January 1986 and with Neptune in August 1989, and is now also en route out of the solar system.

NASA's Voyager 2 spacecraft flew closely past distant Uranus, the seventh planet from the Sun, in January. At its closet, the spacecraft came within 81,800 kilometers (50,600 miles) of Uranus's cloudtops on Jan. 24, 1986. Voyager 2 radioed thousands of images and voluminous amounts of other scientific data on the planet, its moons, rings, atmosphere, interior and the magnetic environment surrounding Uranus.

In the summer of 1989, NASA's Voyager 2 became the first spacecraft to observe the planet Neptune, its final planetary target. Passing about 4,950 kilometers (3,000 miles) above Neptune's north pole, Voyager 2 made its closest approach to any planet since leaving Earth 12 years ago. Five hours later, Voyager 2 passed about 40,000 kilometers (25,000 miles) from Neptune's largest moon, Triton, the last solid body the spacecraft will have an opportunity to study.

This narrow-angle color image of the Earth, dubbed 'Pale Blue Dot', is a part of the first ever 'portrait' of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. This blown-up image of the Earth was taken through three color filters -- violet, blue and green -- and recombined to produce the color image. The background features in the image are artifacts resulting from the magnification.

2024 July 13 - Solar System Family Portrait NASA’s Astronomy Picture of the Day

In today's image, we see a portrait of the solar system showing 6 of the 8 plates in our solar system with Mercury and Mars not being visible because of their position relative to the glare of the Sun. The image was taken by the Voyager 1 spacecraft back in 1990.My podcasts are available in video form through this YouTube Channel (https://www.youtube.com/channel/UCWksELVw1LfYg6TiLQyjByw).This Podcast is an authorized New Media Mirror Site for APOD. You can access the image and website directly at: Astronomy Picture of the Day (https://apod.nasa.gov/apod/astropix.html). You can use the archive link below the image to select the photo corresponding to the date of this podcast.I welcome comments and suggestions about these podcasts. I can be reached here: [email protected] (mailto:[email protected]?subject=APOD%20Podcast)This work is licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).

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