NASA's Voyager 2 Probe Enters Interstellar Space
This illustration shows the position of NASA's Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Voyager 1 exited the heliosphere in August 2012. Voyager 2 exited at a different location in November 2018. Credit: NASA/JPL-Caltech
On August 25th, 2012, the Voyager 1 spacecraft accomplished something no human-made object ever had before. After exploring the Uranus, Neptune, and the outer reaches of the Solar System, the spacecraft entered interstellar space. In so doing, it effectively became the most distant object from Earth and traveled further than anyone, or anything, in history.
Well, buckle up, because according to NASA mission scientists, the Voyager 2 spacecraft recently crossed the outer edge of the heliopause – the boundary between our Solar System and the interstellar medium – and has joined Voyager 1 in interstellar space. But unlike its sibling, the Voyager 2 spacecraft carries a working instrument that will provide the first-ever observations of the boundary that exists between the Solar System and interstellar space.
Earth's Greatest Hits: the Golden Record attached to the Voyager 1 and 2 spacecraft. Credit: NASA/JPL.
Forty years ago, the Voyager 1 and 2 missions began their journey from Earth to become the farthest-reaching missions in history. In the course of their missions, the two probes spent the next two decades sailing past the gas giants of Jupiter and Saturn. And while Voyager 1 then ventured into the outer Solar System, Voyager 2 swung by Uranus and Neptune, becoming the first and only probe in history to explore these worlds.
This summer, the probes will be marking the fortieth anniversary of their launch – on September 5th and August 20th, respectively. Despite having traveled for so long and reaching such considerable distances from Earth, the probes are still in contact with NASA and sending back valuable data. So in addition to being the most distant missions from Earth, they are the longest-running mission in history.
In addition to their distance and longevity, the Voyager spacecraft have also set numerous other records for robotic space missions. For example, in 2012, the Voyager 1 probe became the first and only spacecraft to have entered interstellar space. Voyage 2, meanwhile, is the only probe that has explored all four of the Solar System’s gas/ice giants – Jupiter, Saturn, Uranus and Neptune.
The launch of the Voyager 2 probe, which took place on August 20th, 1977. Credit: NASA
Their discoveries also include the first active volcanoes beyond Earth – on Jupiter’s moon Io – the first evidence of a possible subsurface ocean on Europa, the dense atmosphere around Titan (the only body beyond Earth with a dense, nitrogen-rich atmosphere), the craggy surface of Uranus’ “Frankenstein Moon” Miranda, and the ice plume geysers of Neptune’s largest moon, Triton.
These accomplishments have had immeasurable benefits for planetary science, astronomy and space exploration. They’ve also paved the way for future missions, such as the Galileo and Juno probes, the Cassini-Huygens mission, and the New Horizons spacecraft. As Thomas Zurbuchen, the associate administrator for NASA’s Science Mission Directorate (SMD), said in a recent press statement:
“I believe that few missions can ever match the achievements of the Voyager spacecraft during their four decades of exploration. They have educated us to the unknown wonders of the universe and truly inspired humanity to continue to explore our solar system and beyond.”
But what is perhaps most memorable about the Voyager missions is the special cargo they carry. Each spacecraft carries what is known as the Golden Record, a collection of sounds, pictures and messages that tell of Earth, human history and culture. These records were intended to serve as a sort of time capsule and/or message to any civilizations that retrieved them, should they ever be recovered.
Each of the two Voyager spacecraft launched in 1977 carry a 12-inch gold-plated phonograph record with images and sounds from Earth. Credit: NASA
As noted, both ships are still in contact with NASA and sending back mission data. The Voyager 1 probe, as of the writing of this article, is about 20.9 billion km (13 billion mi; 140 AU) from Earth. As it travels northward out of the plane of the planets and into interstellar space, the probe continues to send back information about cosmic rays – which are about four times as abundant in interstellar space than around Earth.
From this, researchers have learned that the heliosphere – the region that contains the Solar System’s planets and solar wind – acts as a sort of radiation shield. Much in the say that Earth’s magnetic field protects us from solar wind (which would otherwise strip away our atmosphere), the heliopause protects the Solar planets from atomic nuclei that travel at close to the speed of light.
Voyager 2, meanwhile, is currently about 17.7 billion km (11 billion mi; 114.3 AU) from Earth. It is traveling south out of the plane of the planets, and is expected to enter interstellar space in a few years. And much like Voyager 1, it is also studying how the heliosphere interacts with the surroundings interstellar medium, using a suite of instruments that measure charged particles, magnetic fields, radio waves and solar wind plasma.
Once Voyager 2 crosses into interstellar space, both probes will be able to sample the medium from two different locations simultaneously. This is expected to tell us much about the magnetic environment that encapsulates our system, and will perhaps teach us more about the history and formation of the Solar System. On top of that, it will let us know what kinds of hazards a possible interstellar mission will have to contend with.
Illustration showing how NASA’s Hubble Space Telescope is looking along the paths of NASA’s Voyager 1 and 2 spacecraft as they journey through the solar system and into interstellar space. Credit: NASA/ESA/Z. Levy (STScI)
The fact that the two probes are still active after all this time is nothing short of amazing. As Edward Stone – the David Morrisroe Professor of Physics at Caltech, the former VP and Director of NASA’s Jet Propulsion Laboratory, and the Voyager project scientist – said:
“None of us knew, when we launched 40 years ago, that anything would still be working, and continuing on this pioneering journey. The most exciting thing they find in the next five years is likely to be something that we didn’t know was out there to be discovered.”
Keeping the probes going has also been a challenge since the amount of power they generate decreases at a rate of about four watts per year. This has required that engineers learn how to operate the twin spacecraft with ever-decreasing amounts of power, which has forced them to consult documents that are decades old in order to understand the probes’ software and command functions.
Luckily, it has also given former NASA engineers who worked on the Voyager probes the opportunity to offer their experience and expertise. At present, the team that is operating the spacecraft estimate that the probes will run out of power by 2030. However, they will continue to drift along their trajectories long after they do so, traveling at a speed of 48,280 km per hour (30,000 mph) and covering a single AU every 126 days.
The Voyager 1 spacecraft has started to transverse what JPL has dubbed as a “cosmic purgatory” between our solar system – and interstellar space. Credit: NASA/JPL
At this rate, they will be within spitting distance of the nearest star in about 40,000 years, and will have completed an orbit of the Milky Way within 225 million years. So its entirely possible that someday, the Golden Records will find their way to a species capable of understanding what they represent. Then again, they might find their way back to Earth someday, informing our distant, distant relatives about life in the 20th century.
And if the craft avoid any catastrophic collisions and can survive in the interstellar medium of space, it is likely that they will continue to be emissaries for humanity long after humanity is dead. It’s good to leave something behind!
Setting foot on a distant planet… we’ve all dreamed about it at one time or another. And it has been a staple of science fiction for almost a century. Engage the warp dive, spool up the FLT, open a wormhole, or jump into the cryochamber. Next stop, Alpha Centauri (or some other star)! But when it comes to turning science fiction into science fact, there are certain unfortunate realities we have to contend with. For starters, none of the technology for faster-than-light travel exists!
Second, sending crewed mission to even the nearest planets is a very expensive and time consuming endeavor. But thanks to ongoing developments in the fields of miniaturization, electronics and direct-energy, it might be possible to send tiny spacecraft to distant stars in a single lifetime, which could carry something of humanity along with them. Such is the hope of Professor Philip Lubin and Travis Bradshears, the founders of “Voices of Humanity“.
For people familiar with directed-energy concepts, the name Philip Lubin should definitely ring a bell. A professor from the University of California, Santa Barbara (UCSB), he is also the mind behind the NASA-funded Directed Energy Propulsion for Interstellar Exploraiton (DEEP-IN) project, and the Directed Energy Interstellar Study. These projects seek to use laser arrays and large sails to achieve relativistic flight for the sake of making interstellar missions a reality.
Looking beyond propulsion and into the realm of public participation in space exploration, Prof. Lubin and Bradshears (an engineering and physics student from the University of California, Berkeley) came together to launch Voices of Humanity (VoH) in 2015. Inspired by their work with NASA, this Kickstarter campaign aims to create the world’s first “Space Time Capsule”.
Intrinsic to this is the creation of a Humanity Chip, a custom semiconductor memory device that can be attached to the small, wafer-scale spacecraft that are part of DEEP-IN and other directed-energy concepts. This chip will contain volumes of data, including tweets, media files, and even the digital DNA records of all those who want to take part in the mission. As Professor Lubin told Universe Today in a phone interview:
“We wanted to put on board some part of humanity. We couldn’t shrink ray people down, so Travis and I brainstormed and thought that the next best thing would be to allow people to become digital astronauts. We wanted to pave the way for interstellar missions where we could send the essence of humanity to the stars – “Emissaries of the Earth”, if you will. We wanted to pave the way for that.”
This digital archive would be similar to the Golden Record that was placed on the Voyager probes, but would be much more sophisticated. Taking advantage of all the advances made in computing, electronics and data storage in recent decades, it would contain many millions of times the data, but comprise a tiny fraction of the volume.
In fact, as Lupin explained, the state of technology today allows us to create a digital archive that would be about the same size a fingernail, and which would require no more than a single gram of mass to be allocated on a silicon wafer-ship. And while such a device is not the same as sending astronauts on interstellar voyages to explore other planets, it does allow humanity to send something of itself.
“We now have the technology to put a message from everyone on Earth onto a small piece of a tiny spacecraft,” said Lupin. “We want to begin today, and not just for the future, by putting information onto anything that is launched from Earth. We are the point technologically, at this moment, that we could put a small portion of humanity on this spacecraft.”
In essence, human beings would be able to create the interstellar equivalent of a “Baby on Board” sticker, except for humanity instead. This sticker would be no larger than a postage stamp, and could be mounted on every craft to leave Earth in the near future. In essence, all missions departing from Earth could have “Humanity on Board”.
The plan is to launch their first chip – Humanity Chip 1.0 – into Low Earth Orbit (LEO) in 2017. This will be followed by the creation of Humanity Chip 2.0, which take advantage of the developments that will have occurred by next year. Eventually, they hope that Humanity Chips will be a part of missions that increase in distance from Earth, eventually culminating in a mission to interstellar space.
Artist’s rendition of The Humanity chip placed on a silicon wafer spacecraft. Credit: Voices of Humanity/kickstarter.com
While there are no deep-space missions ready to go just yet, several concepts are on the table for interplanetary missions that will rely on wafer-scale spacecraft (like NASA’s DEEP-IN concept). If their Kickstarter campaign succeeds in raising the $30,000 necessary to create a Humanity Chip, Prof. Lubin and Bradshears also hope to create a “Black Hole Chip”, where participants will be able to record their “less than happy” thoughts as part of the data, which will then be sent off into space forever.
They also have a stretch goal in mind, known as the “Beam Me Up” objective. In the event that their campaign is able to raise $100,000, they will use the funds to create a ground-based laser array that will beam a package of encoded data towards a target destination in space.
As of the penning of this article, Prof. Lubin and Bradshears have raised a total of $5,656 towards their goal of $30,000. The campaign kicked off earlier this month and will remain open for another 22 days. So if you’re interested in contributing to Humanity Chip 1.0, or becoming an “Emissary of the Earth”, there’s still plenty of time.
In addition to his work with NASA, Prof. Lubin is also responsible for the UCSB’s Directed Energy System for Targeting of Asteroids and ExploRation (DE-STAR) project, a proposed system that would use directed energy (i.e. big lasers!) to deflect asteroids, comets, and other near-Earth objects (NEOs) that could pose a risk to planet Earth.
The Black Hole Chip is one of the stretch goals, which will send “less than happy” thoughts into space. Credit: Voices of Humanity/kickstarter.com
And, in a recent article titled “The Search for Directed Intelligence“- which appeared in the March 2016 issue of REACH – Reviews in Human Space Exploration – Lupin indicated that advances in directed-energy applications might also help in the search for extra-terrestrial intelligence. Essentially, by looking for for sources of directed energy systems, he claims, we might be able to find our way to other civilizations.
It is an exciting age, where advances in telecommunications and electronics are allowing us to overcome the vast distances involved in space travel. In the future, astronauts may rely on robotic explorers and fast-as-light communications to explore distant worlds (a process known as telexploration). And with a digital archive on board, we will be able to send personal greetings to any life that may already exist there.
For those who would say “sharing personal information with extra-terrestrials is a bad idea”, I would remind them that they (probably) don’t have access to Twitter or our financial records. All the same, it might be wise not to include your Social Security (or Social Insurance) number in the recordings, or any other personal data you wouldn’t share with strangers!
And who knows? Someday, we may start colonizing other planets by sending our DNA there direct. The truth is always stranger than fiction, after all!
And be sure to check out this video produced by Voices for Humanity:
Credit: Inside Science News Service and Amanda Page
As the Beatles strummed the opening notes to “All My Loving” on the Ed Sullivan Show 50 years ago yesterday, few could have imagined how wide-ranging that music would be. The broadcast gave birth to a global music phenomenon. And like all TV broadcasts of the day, the music carried out into space at the speed of light.
The Inside Science infographic above (see below for the full version) traces the history of the Beatles in relation to how far the broadcast travelled in that time. While those waves were washing out, er, across the universe, the Beatles have been taking over human space exploration in other ways. Below the jump are seven of the more memorable moments.
Rocking The Space Station With ‘Back at the ISS’
Technically speaking, this isn’t the Beatles, but it sure was inspired by them. ‘Back at the ISS’ — the remake of ‘Back in the U.S.S.R.’ by Dutch band Love & Mersey — is about a billion shades of awesome. Not only because of the lyrics, not only because of the high-energy space-themed video, but also because they sang in three languages. The song was released in March 2012 as a “rocking musical greeting” to Andre Kuipers (a European Space Agency astronaut) and the rest of the Expedition 30 crew days before the docking of the Automated Transfer Vehicle Edoardo Amaldi that month.
The Beatles have been used to wake up several shuttle crews, and also the Curiosity rover. Explained Eric Blood, Curiosity’s surface systems engineer: “She tends to be less cranky with a good wakeup song.”
Playing (And Drinking?) English Tea In Space
Here’s Paul McCartney in 2005 casually playing two tunes to the Expedition 12 crew — NASA astronaut Bill McArthur and Russian cosmonaut Valery Tokarev — during a live concert. It’s a bit hard to tell who had bigger stars in their eyes after the experience. “I told the audience ‘I think I need about 20 minutes to go have a lie down,’ McCartney stated in a NASA release from the time. “What do you do after that? We haven’t stopped talking about it since.”
Roll Over Beethoven: How The Beatles Almost Made Voyager’s ‘Golden Record’
Remember when scientists announced last year that Voyager 1 entered interstellar space? On board the spacecraft was a Golden Record intended to give aliens a glimpse into what Earth’s life is like. Included were songs from artists ranging from Bach to Blind Willie Johnson, but not the Beatles. They were almost included, though, as astronomer Carl Sagan (who chaired the selection committee) explained in his 1978 book Murmers of Earth. “We wanted to send ‘Here Comes The Sun’ by the Beatles, and all four Beatles gave their approval. But the Beatles did not own the copyright, and the legal status of the piece seemed too murky to risk,” he wrote.
Joining Mr. Mercury’s Light
There are so many earthly memorials to John Lennon after the singer’s untimely death in 1980, but late last year he got an extraterrestrial honor. Lennon was among 10 names approved for craters on the planet Mercury. “It’s unlikely that Mercury’s surface is populated with tangerine trees and marmalade skies, but the famous British musician who coined that phrase now has a physical presence on the planet closest to the Sun,” NASA said.
Sending Love To The Aliens With Jai Guru Deva Om
February 4, 2008 marked the first time NASA beamed any song into deep space, and what better choice than “Across The Universe”? The date marked the 40th anniversary of when the Beatles recorded the song, and came around the same time as the 45th anniversary of NASA’s Deep Space Network and the 50th anniversary of NASA’s first satellite, Explorer 1, among other milestones. In a statement, McCartney asked to “send my love to the aliens.”
What Beatles milestones in space have we missed? Let us know in the comments.
Since the dawn of the Space Age in 1957, thousands of artifacts and memorabilia have been flown into space. Some have been hoisted on brief suborbital flights, while others have been flung out of the solar system, never to return. And of course, it’s become a fashionable — and highly commercialized — trend as of late to briefly loft products, stuffed animals, etc via balloon towards the tenuous boundary of space. Fly a souvenir or artifact into orbit, and it goes from mundane to priceless. But a few may also serve as a final testament to the our ephemeral existence as a species long after our passing.
Here’s a look at some of the most memorable objects sent into space:
The Florida State Quarter dispatched with New Horizons. Image Credit: NASA/Bill Rodgers, JHU/APL.
New Horizons Memorabilia
Launched on January 19th, 2006, New Horizons is headed towards a historic encounter with Pluto and its moons next year. From there, New Horizons will survey any Kuiper Belt objects of opportunity along its path and then head out of the solar system, becoming the fifth spacecraft to do so. In addition to a suite of scientific instruments, New Horizons also carries the ashes of Pluto discoverer Clyde Tombaugh, a Florida & Maryland state quarter, a piece of Scaled Composites SpaceShipOne, and an American flag. These will doubtless confuse any extraterrestrial salvagers!
The Humanoids Where Here: the plaque affixed the the Pioneer 10 & 11 spacecraft. Credit: NASA/JPL.
The Pioneer Plaques
The first spacecraft sent on escape trajectories out of our solar system, the Pioneer 10 and 11 spacecraft each carry a plaque which serves as a sort of postcard “greeting” to any future interceptors. The plaque depicts a diagram of the solar system, a map of our location in the galaxy using the positions of known pulsars, and a nude man & woman, which actually generated lots of controversy. Scientist James Van Allen tells of deliberately placing a fingerprint on the Pioneer 10 plaque in his biography The First Eight Billion Miles.
Earth’s Greatest Hits: the Golden Record attached to the Voyager 1 and 2 spacecraft. Credit: NASA/JPL.
The Voyager 1 and 2 Golden Records
Conceived and designed in part by Carl Sagan, these records contain images and sounds of the Earth that’ll most likely outlive humanity. The records carry greetings in 55 languages, music ranging from Mozart to Chuck Berry, 116 images and more, along with instructions and a stylus for playback. The record is also enclosed in an aluminum cover electroplated with Uranium-238, which an alien civilization could use to date its manufacture via half-life decay.
A closeup of the “Mars Penny.” Credit: NASA/JPL-Caltech.
The Mars Curiosity Penny
Strange but true: The Mars rover Curiosity carries a 1909 U.S. Penny for a backup camera calibration target. The penny itself is embedded just below the primary color calibration targets used by Curiosity’s MArs Hand Lens Imager (MAHLI). Rare enough on Earth, the 1909 Lincoln “Mars penny” will be priceless to future collectors!
Jupiter-bound figurines from left: Jupiter, Juno, & Galileo. Credit: NASA.
Juno’s LEGO Figurines
Mini-figurines of Galileo and the Roman deities Jupiter and Juno were launched in 2011 aboard NASA’s Juno spacecraft en route to Jupiter . LEGO has flown products aboard the U.S. Space Shuttles and to the International Space Station previously, but Juno’s cargo represents the “most distant LEGO launch” ever. The figurines will burn up in Jupiter’s atmosphere along with the spacecraft at the end of the mission in October 2017.
An Apollo 15 postal cover flown to the Moon. Credit: NASA.
Apollo 15 Postal Covers Fiasco
Apollo 15 astronauts got in some hot water over a publicity scheme. The idea that stamp collector and dealer Hermann Sieger approached the astronauts with was simple: 400 commemorative postage stamp covers would be postmarked at point of departure from the Kennedy Space Center and again at the return point of arrival aboard the USS Okinawa after their circuitous journey via the Moon. NASA was less than happy with the whole affair, and Command Module Pilot Al Worden recounts the aftermath in his book, Falling to Earth.
A Marsbound DVD… Courtesy of Lockheed Martin/LSP.
Haiku for MAVEN
Last year’s MAVEN mission to Mars also carried haiku submitted by space fans. Over 12,530 valid entries were submitted and over 1,100 haiku received the necessary minimum of two votes to be included on a DVD disk affixed to the spacecraft. MAVEN reaches orbit around Mars in October 2014.
The copy of the Soviet pennant aboard Luna 2 on display at the Kansas Cosmoshpere. Credit: Patrick Pelletier under a Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license.
Luna 2: A Russian Pennant on Moon
On September 12th, 1959, the Soviet Union’s Luna 2 spacecraft became the first man-made object to impact the Moon. Luna 2 carried two spherical “pennants” composed of pentagon-shaped elements engraved with the USSR Coat of Arms and Cyrillic letters translating into “CCCP/USSR September 1959.” An identical pennant is now on display in the Kansas Cosmosphere.
EchoStar XVI in its clean room. Credit: Space Systems Loral.
A GeoSat Time Capsule Aboard EchoStar XVI
A disk entitled Last Pictures similar to the Voyager records was placed on a satellite headed to geosynchronous orbit in 2012. Launched aboard EchoStar XVI, Last Pictures is an ultra-archival disk containing 100 snapshots of modern life along with interviews with several 21st century artists and scientists. Geosynchronous satellites aren’t subject to atmospheric drag, and may be the last testament to the existence of humanity on Earth millions of years hence.
An artist’s conception of NASA’s Lunar Prospector mission leaving Earth orbit. Credit: NASA.
Lunar Prospector Carries An Astro-Geologist’s Ashes to the Moon
Though he never made the selection to become an astronaut, scientist Eugene Shoemaker did make a posthumous trip to the Moon. The Lunar Prospector spacecraft departed Earth with Shoemaker’s ashes on January 7th, 1998 in a capsule wrapped in brass foil. Lunar Prospector impacted the south pole of the Moon on July 31st, 1999.
The SpaceX Dragon capsule on approach to the ISS during the COTS 2 mission. Credit: NASA.
SpaceX Takes Star Trek Actor to Space
The ashes actor James Doohan (AKA Scotty) were launched aboard a 2012 SpaceX flight to the International Space Station. The COTS Demo Flight, or COTS 2, was the first commercial spacecraft to berth at the ISS. SpaceX had flown a small amount of Doohan’s ashes on the 2008 unsuccessful test launch of the Falcon 1 rocket.
The “Top Secret Payload” of the Dragon capsule revealed. Credit: Chris Thompson/SpaceX.
Cheese Wheel Makes a Suborbital Journey
All eyes were also on SpaceX during their December 8th 2010 maiden flight of the Dragon space capsule. And the hinted mystery cargo? None other than a wheel of cheese, a nod by SpaceX CEO Elon Musk to a classic Monty Python sketch.
The Apollo 12 “Moon Museum”
Did it really go into space? One of the legends surrounding the Apollo program is the existence of what’s been dubbed the “Moon Museum.” This was a postage stamp-sized “gallery” of art which included a sketch by Andy Warhol and other 1960s artists that was supposedly attached to descent stage of Apollo 12 and left on the Moon. It will be up to future lunar visitors to confirm or deny its existence!
…And lastly, I give you the “Space Hubcap”
Was the first man-made object propelled into space actually a 1 ton armor plate? On August 27th, 1957 — just two months prior to Sputnik 1 — the Pascal-B underground nuclear test was conducted in southern Nevada. During the explosion, a steel plate cap was blasted off of a test shaft. The plate could be seen in the initial high-speed video frames, and it was estimated to have reached a speed six times the sufficient escape velocity to depart Earth. To this day, no one knows if this strange artifact of early Space Age folklore still roams the void of space, or simply vaporized due to atmospheric compression at “launch”.
The Voyager spacecraft have been on an extensive mission of discovery that has lasted some 36 years. Image Credit: NASA/JPL
Yesterday, NASA announced that as of August 2012, Voyager 1 is in a new frontier to humanity: interstellar space. Our most distant spacecraft is now in a region where the plasma (really hot gas) environment comes more from between the stars than from the sun itself. (There’s still debate as to whether it’s in or out of the solar system, as this article explains.)
The plucky spacecraft is close to 12 billion miles (19 million kilometers) from home, and in its 36 years of voyaging has taught us a lot about the planets, their moons and other parts of space. Here are 10 of some of its most historic moments. Did we miss any? Let us know in the comments.
10. The launch: Aug. 20, 1977
Voyager 1 launches from the Kennedy Space Center on Sept. 5, 1977. Credit: NASA
Voyager 1 blasted off from Cape Canaveral on Sept. 5, 1977. Its twin, Voyager 2, departed Earth 16 days earlier. Each spacecraft carried various scientific instruments on board as well as a “Golden Record” that had sounds of Earth on it, as well as a diagram showing where Earth is in the universe.
9. Capturing the Earth and Moon together for the first time
On Sept. 18, 1977, Voyager 1 took three images of the Earth and Moon that were combined into this one image. The moon is artificially brightened to make it show up better. Credit: NASA
About two weeks after launching, Voyager 1 turned back towards Earth and took three images, which were combined into this single view of the Earth and Moon together in space. This was the first time both bodies were pictured together, NASA said.
8. The ‘Pale Blue Dot’ image
Voyager 1 pale blue dot. Image credit: NASA/JPL
On February 14, 1990, Voyager 1 was about 3.7 billion miles (6 billion kilometers) away from Earth. Scientists commanded the spacecraft to turn its face towards the solar system and snap some pictures of the planets. Among them was this famous image of Earth, which astronomer Carl Sagan called the Pale Blue Dot. “Look again at that dot. That’s here. That’s home. That’s us,” wrote Sagan in his 1997 book of the same name. In 2013, the spacecraft Cassini also took a picture of Earth, and NASA encouraged everyone to wave back.
7. Finding moons “shepherding” Saturn’s F ring
Prometheus, a small potato-shaped moon of Saturn, shown in this Voyager 1 picture interacting with the planet’s F ring. Credit: NASA/JPL/SSI
Voyager 1 spotted Prometheus and Pandora, two moons of Saturn that keep the F ring separate from the rest of the debris, as well as Atlas, which “shepherds” the A ring. More recently, astronomers have found even more interesting things in Saturn’s rings — such as rain.
6. Spotting what appeared to be a LOT of water ice on Saturn’s moons
Encaladus, a moon of Saturn, as shown in this Voyager 1 image. Credit: NASA
After many years of seeing Saturn’s moons as mere points of light, Voyager 1 buzzed several of them in its quick flyby through the system: Dione, Enceladus, Mimas, Rhea, Tethys and Titan among them. Many of these moons appeared to be icy, which was a surprising find since astronomers previously thought water was pretty rare in the Solar System. We know better now.
5. Imaging Titan’s orange haze
Saturn’s moon Titan lies under a thick blanket of orange haze in this Voyager 1 picture. Credit: NASA
Voyager 1 pictures such as this tortured astronomers for decades — what lies beneath this mysterious haze surrounding Titan, Saturn’s moon? That mystery, in fact, inspired the European Space Agency to send a lander to the moon, called Huygens, which successfully reached the surface in 2005.
4. Finding active volcanoes on Io
Io’s blotchy volcanoes are clearly visible in this image from Voyager 1. Credit: NASA
Voyager 1 helped show us that the Solar System is full of very interesting moons. At Io — a moon of Jupiter — it turns out the moon flexes during its 42-hour orbit of massive Jupiter, which powers a lot of volcanic activity.
3. Voyager 1 becomes the most distant human object
A 2013 computer-generated snapshot riding along with Voyager 1’s looking back at the Sun and inner solar system. The positions of Voyager 2 and Pioneers 10 and 11 show within the viewport as well.
On Feb. 17, 1998, Voyager 1’s distance surpassed that of another long-flying probe, Pioneer 10. This made Voyager 1 the farthest-flung human object in space.
2. Riding the “magnetic highway”
Artist concept of NASA’s Voyager 1 spacecraft exploring a new region in our solar system called the “magnetic highway.” Credit: NASA/JPL-Caltech
In December, NASA said Voyager 1 had reached an area (as of July 28, 2012) where high-energy magnetic particles were starting to bleed through the bubble of lower-energy particles from our sun. “Voyager’s discovered a new region of the heliosphere that we had not realized was there. It’s a magnetic highway where the magnetic field of the Sun is connected to the outside. So it’s like a highway, letting particles in and out,” said project scientist Ed Stone at the time. After that point, as more measurements were analyzed by different teams, there was a lot of debate as to whether Voyager had reached interstellar space.
1. Reaching interstellar space
This graphic shows the main evidence that Voyager 1 has reached interstellar space. The blue line shows particle density, which dropped as Voyager 1 moved away from the sun, and then jumped again after it crossed the “termination shock” that is where the sun’s solar wind (particles streaming from the sun) slows down. Credit: NASA/JPL-Caltech
With Voyager 1 now known to be in interstellar space, we’re lucky enough to have a few years left to communicate with it before it runs out of power. All of the instruments will be turned off by 2025, and then engineering data will be available for about 10 years beyond that. The silent emissary from humanity will then come within 1.7 light years of an obscure star in the constellation Ursa Minor (the Little Bear) called AC+79 3888 in the year 40,272 AD and then orbit the center of the Milky Way for millions of years.
