NRAO Very Long Baseline Array takes radio image of Voyager 1

Credit: NRAO/AUI/NSF

The image above is a radio image of Voyager 1.

It was taken from NRAO's Very Long Baseline Array (VLBA), which is a collection of 10 radio telescopes scattered from Hawaii to the Virgin Islands.

It captures the faint radio signal of the distant probe. That pale blue dot is the most distant object made by humans.

The radio strength of Voyager 1 is about 23 watts. That signal is directed toward Earth, but Voyager is about 15 billion kilometers from Earth, so by the time the probe's signal reaches us its power is less than an attowatt, or a billionth of a billionth of a watt.

That faint signal is the only information we have from a probe that left our planet 36 years ago.

Of course it isn't enough to simply detect the signal from Voyager 1, we must receive the signal the way you might receive a radio signal, or a mobile phone call.

That requires even greater sensitivity, which is why it requires large radio telescopes to communicate with Voyager.

We have to be able to hear Voyager's faint messages, and we have to send radio responses that are powerful enough and focused enough for Voyager to receive.

Voyager 1 has, arguably, entered interstellar space, but has only begun its journey to the edge of our solar system.

It will eventually leave our Sun's grasp, since it has enough speed to escape the Sun's gravity, but it will become silent long before then.

In another 5 – 10 years it won't have enough power to operate its instruments.

That's part of what makes this current milestone so significant. Voyager 1 has not only reached interstellar space, but it has communicated the fact to us and we have gained knowledge and insight from it.

That pale blue dot, a radio blip in a radio dark sky, is a part of us.

It is an 800 kg, car sized, nuclear-powered computer that we launched into space to explore the solar system.

Our curiosity and quest for knowledge drove us to create it, and our developing intelligence allowed us to build it.

After a 36 year journey towards the harshness of interstellar space, it continues to communicate with its creators.

Looking out from one pale blue dot towards another one.

(Taken from an article by Brian Koberlein)

Sun sends more 'shock waves' to Voyager 1 - Video

Credit: NASA/JPL-Caltech

NASA's Voyager 1 spacecraft has experienced a new "shock wave" from the sun as it sails through interstellar space.

Such waves are what led scientists to the conclusion, in the fall of 2013, that Voyager had indeed left our sun's bubble, entering a new frontier.

"Normally, interstellar space is like a quiet lake," said Ed Stone of the California Institute of Technology in Pasadena, California, the mission's project scientist since 1972.

"But when our sun has a burst, it sends a shock wave outward that reaches Voyager about a year later. The wave causes the plasma surrounding the spacecraft to sing."

Data from this newest tsunami wave generated by our sun confirm that Voyager is in interstellar space, a region between the stars filled with a thin soup of charged particles, also known as plasma.

The mission has not left the solar system, it has yet to reach a final halo of comets surrounding our sun, but it broke through the wind-blown bubble, or heliosphere, encasing our sun.

Voyager is the farthest human-made probe from Earth, and the first to enter the vast sea between stars.

"All is not quiet around Voyager," said Don Gurnett of the University of Iowa, Iowa City, the principal investigator of the plasma wave instrument on Voyager, which collected the definitive evidence that Voyager 1 had left the sun's heliosphere.

"We're excited to analyze these new data. So far, we can say that it confirms we are in interstellar space."




The first two tsunami waves to reach Voyager 1 caused surrounding ionized matter to ring like a bell at frequencies expected in interstellar space. 

The third tsunami caused similar ringing, confirming that Voyager 1 continues it journey into interstellar space. 

Image Credit: NASA's Voyager 1 spacecraft

Our sun goes through periods of increased activity, where it explosively ejects material from its surface, flinging it outward. These events, called coronal mass ejections, generate shock, or pressure, waves.

Three such waves have reached Voyager 1 since it entered interstellar space in 2012. The first was too small to be noticed when it occurred and was only discovered later, but the second was clearly registered by the spacecraft's cosmic ray instrument in March of 2013.

Cosmic rays are energetic charged particles that come from nearby stars in the Milky Way galaxy. The sun's shock waves push these particles around like buoys in a tsunami.

Data from the cosmic ray instrument tell researchers that a shock wave from the sun has hit.

Meanwhile, another instrument on Voyager registers the shock waves, too. The plasma wave instrument can detect oscillations of the plasma electrons.

"The tsunami wave rings the plasma like a bell," said Stone. "While the plasma wave instrument lets us measure the frequency of this ringing, the cosmic ray instrument reveals what struck the bell—the shock wave from the sun."

This ringing of the plasma bell is what led to the key evidence showing Voyager had entered interstellar space. Because denser plasma oscillates faster, the team was able to figure out the density of the plasma.

In 2013, thanks to the second tsunami wave, the team acquired evidence that Voyager had been flying for more than a year through plasma that was 40 times denser than measured before, a telltale indicator of interstellar space.

Why is it denser out there? The sun's winds blow a bubble around it, pushing out against denser matter from other stars.

Now, the team has new readings from a third wave from the sun, first registered in March of this year.

These data show that the density of the plasma is similar to what was measured previously, confirming the spacecraft is in interstellar space.

Thanks to our sun's rumblings, Voyager has the opportunity to listen to the singing of interstellar space, an otherwise silent place.

Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn.

Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft and is expected to enter interstellar space in a few years.

Voyager 3: Amateur timelapse of Jupiter 're-enacts' Voyager 1 1970 flyby

This animated gif shows Voyager 1′s approach to Jupiter during a period of over 60 Jupiter days in 1979. 

Credit: NASA

Back in the 1970′s when NASA launched the two Voyager spacecraft to Jupiter, Saturn, Uranus, and Neptune, we were all mesmerised by a movie created from Voyager 1 images of the movement of the clouds in Jupiter's atmosphere.

Voyager 1 began taking pictures of Jupiter as it approached the planet in January 1979 and completed its Jupiter encounter in early April.

During that time it took almost 19,000 pictures and many other scientific measurements to create the short movie, which you can see below, showing the intricate movement of the bright band of clouds for the first time.

Now, 35 years later a group of seven Swedish amateur astronomers achieved their goal of replicating the Voyager 1 footage, not with another flyby but with images taken with their own ground-based telescopes.

"We started this joint project back in December of 2013 to redo the NASA Voyager 1 flyby of Jupiter," amateur astronomer Göran Strand told reporters.

"During 90 days we captured 560 still images of Jupiter and turned them into 90 complete maps that covered the whole of Jupiter's surface."


Their newly released film, above details the work they did and the hurdles they overcame (including incredibly bad weather in Sweden this winter) to make their dream a reality.

They called their project "Voyager 3."

It is really an astonishing project and those of you who do image processing will appreciate the info in the video about the tools they used and how they did their processing to create this video.

The Swedish team of amateur astronomers who compiled the ‘Voyager 3′ project. 

Credit: Göran Strand

IBEX: Scientists reveal cosmic roadmap to galactic magnetic field

Cosmic ray intensities (left) compared with predictions (right) from IBEX. 

The similarity between these observations and predictions—as evidenced by the similar colour regions—supports the local galactic magnetic field direction determined from IBEX observations made from particles at vastly lower energies than the cosmic ray observations shown here. 

The blue area represents regions of lower fluxes of cosmic rays. 

The gray and white lines separate regions of different energies—lower energies above the lines, high energies below. 

Credit: Nathan Schwadron, UNH-EOS.

Scientists on NASA's Interstellar Boundary Explorer (IBEX) mission, including a team leader from the University of New Hampshire, report that recent, independent measurements have validated one of the mission's signature findings—a mysterious "ribbon" of energy and particles at the edge of our solar system that appears to be a directional "roadmap in the sky" of the local interstellar magnetic field.

Unknown until now, the direction of the galactic magnetic field may be a missing key to understanding how the heliosphere—the gigantic bubble that surrounds our solar system—is shaped by the interstellar magnetic field and how it thereby helps shield us from dangerous incoming galactic cosmic rays.

"Using measurements of ultra-high energy cosmic rays on a global scale, we now have a completely different means of verifying that the field directions we derived from IBEX are consistent," says Nathan Schwadron, lead scientist for the IBEX Science Operations Center at the UNH Institute for the Study of Earth, Oceans, and Space.

Schwadron and IBEX colleagues published their findings online today in Science Express.

Establishing a consistent local interstellar magnetic field direction using IBEX low-energy neutral atoms and galactic cosmic rays at ten orders of magnitude higher energy levels has wide-ranging implications for the structure of our heliosphere and is an important measurement to be making in tandem with the Voyager 1 spacecraft, which is in the process of passing beyond our heliosphere.

An all-sky map made by the IBEX spacecraft shows a surprising bright ribbon of emission coming from the edge of the solar system. 

Credit: Southwest Research Institute (SwRI)

"The cosmic ray data we used represent some of the highest energy radiation we can observe and are at the opposite end of the energy range compared to IBEX's measurements," says Schwadron.

"That it's revealing a consistent picture of our neighbourhood in the galaxy with what IBEX has revealed gives us vastly more confidence that what we're learning is correct."

How magnetic fields of galaxies order and direct galactic cosmic rays is a crucial component to understanding the environment of our galaxy, which in turn influences the environment of our entire solar system and our own environment here on Earth, including how that played into the evolution of life on our planet.

David McComas, principal investigator of the IBEX mission at Southwest Research Institute and coauthor on the Science Express paper says, "We are discovering how the interstellar magnetic field shapes, deforms, and transforms our entire heliosphere."

More information: "Global Anisotropies in TeV Cosmic Rays Related to the Sun's Local Galactic Environment from IBEX," by N.A. Schwadron et al. Science, 2014. www.sciencemag.org/content/early/2014/02/12/science.1245026

Voyager 1 has left the Solar System - Heliosphere Boundary crossed

Voyager 1 appears to have at long last left our solar system and entered interstellar space, says a University of Maryland-led team of researchers.

Carrying Earthly greetings on a gold plated phonograph record and still-operational scientific instruments – including the Low Energy Charged Particle detector designed, built and overseen, in part, by UMD's Space Physics Group – NASA's Voyager 1 has traveled farther from Earth than any other human-made object and now, these researchers say, it has begun the first exploration of our galaxy beyond the Sun's influence.

"It's a somewhat controversial view, but we think Voyager has finally left the Solar System, and is truly beginning its travels through the Milky Way," says UMD research scientist Marc Swisdak, lead author of a new paper published online this week in The Astrophysical Journal Letters.

Swisdak and fellow plasma physicists James F. Drake, also of the University of Maryland, and Merav Opher of Boston University have constructed a model of the outer edge of the Solar System that fits recent observations, both expected and unexpected.

Their model indicates Voyager 1 actually entered interstellar space a little more than a year ago, a finding directly counter to recent papers by NASA and other scientists suggesting the spacecraft was still in a fuzzily-defined transition zone between the Sun's sphere of influence and the rest of the galaxy. But why the controversy?

At issue is what the boundary-crossing should look like to Earth-bound observers 11 billion miles (18 billion kilometers) away.

The Sun's envelope, known as the heliosphere, is relatively well-understood as the region of space dominated by the magnetic field and charged particles emanating from our star.

The heliopause transition zone is both of unknown structure and location. According to conventional wisdom, we'll know we've passed through this mysterious boundary when we stop seeing solar particles and start seeing galactic particles, and we also detect a change in the prevailing direction of the local magnetic field.

NASA scientists recently reported that last summer, after eight years of travel through the outermost layer of the heliosphere, Voyager 1 recorded "multiple crossings of a boundary unlike anything previously observed."

Successive dips in, and subsequent recovery of, solar particle counts caught researchers' attention.

The dips in solar particle counts corresponded with abrupt increases in galactic electrons and protons. Within a month, solar particle counts disappeared, and only galactic particle counts remained.

Yet Voyager 1 observed no change in the direction of the magnetic field.

To explain this unexpected observation, many scientists theorize that Voyager 1 has entered a "heliosheath depletion region," but that the probe is still within the confines of the heliosphere.

Swisdak and colleagues, who are not part of the Voyager 1 mission science teams, say there is another explanation.

In previous work, Swisdak and Drake have focused on magnetic reconnection, or the breaking and reconfiguring of close and oppositely-directed magnetic field lines.

It's the phenomenon suspected to lurk at the heart of solar flares, coronal mass ejections and many of the sun's other dramatic, high-energy events. The UMD researchers argue that magnetic reconnection is also key to understanding NASA's surprising data.

Though often depicted as a bubble encasing the heliosphere and its contents, the heliopause is not a surface neatly separating "outside" and "inside." In fact, Swisdak, Drake and Opher assert that the heliopause is both porous to certain particles and layered with complex magnetic structure.

Here, magnetic reconnection produces a complex set of nested magnetic "islands," self-contained loops which spontaneously arise in a magnetic field due to a fundamental instability.

Interstellar plasma can penetrate into the heliosphere along reconnected field lines, and galactic cosmic rays and solar particles mix vigorously.

Most interestingly, drops in solar particle counts and surges in galactic particle counts can occur across "slopes" in the magnetic field, which emanate from reconnection sites, while the magnetic field direction itself remains unchanged.

This model explains observed phenomena from last summer, and Swisdak and his colleagues suggest that Voyager 1 actually crossed the heliopause on July 27, 2012.

In a NASA statement, Ed Stone, Voyager project scientist and a professor of physics of the California Institute of Technology, says, in part, "Other models envision the interstellar magnetic field draped around our solar bubble and predict that the direction of the interstellar magnetic field is different from the solar magnetic field inside. By that interpretation, Voyager 1 would still be inside our solar bubble.

The fine-scale magnetic connection model [of Swisdak and colleagues] will become part of the discussion among scientists as they try to reconcile what may be happening on a fine scale with what happens on a larger scale."

Voyager Interstellar Mission
In the 36th year after their 1977 launches, the twin Voyager 1 and 2 spacecraft continue exploring where nothing from Earth has flown before.

Their primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there—such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings—the mission was extended.

Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets.

The current mission for both spacecraft, the Voyager Interstellar Mission, is to explore the outermost edge of the Sun's domain and beyond.

Both Voyagers are capable of returning scientific data from a full range of instruments, with adequate electrical power and attitude control propellant to keep operating until 2020.

Voyager 2 is expected to enter interstellar space a few years after its twin. The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif.

University of Maryland scientists lead the Deep Impact spacecraft science team and are part of the science teams of many of the other spacecraft exploring our Solar System, including both Voyagers and Cassini.

More information: Paper: dx.doi.org/10.1088/2041-8205/774/1/L8

The Canberra Deep Space Comms Complex spruced up

AUSTRALIAN ingenuity will save NASA about $800,000 and three months of down time when the 70-metre antenna at the Canberra Deep Space Communications Complex is shut for refurbishment in November.

Visitors gazing at the sparkling 4000-tonne dish would never know the paint has failed and is cracked and peeling, reducing its reliability.

For a piece of extremely sensitive equipment that detects radio waves sent from Voyager 1 with half as much power as a fridge light, surface consistency to 0.1 millimetre is critical.

It takes radio waves from Voyager 1 about 14 hours to reach Earth and by the time they arrive, they have faded markedly from 12 watts to 20 million times weaker than a watch battery.

Mechanical engineer John Phillips is the deputy antenna site facility manager and will be part of a team overseeing the replacement of the grout beneath the antenna and the painting of the dish.

''It will do the same function but reliability will be improved. If you get deformation in the grout that supports the runner, the antenna itself is not as good,'' Mr Phillips said.

''If you get deformation in the runner because the support isn't that good, it stops the antenna from working.''

The original plan was to jack up the antenna and bolt legs on to replace the grout in one go.

''It would have cost twice that and they were estimating down time of more than 10 months.''

The new plan will replace the grout in 60-degree sections and close it from November 12 to June 6.

The new grout is impervious to oil and should last decades. ''It's an epoxy with a crushed quartz mix. With the new grout, that should improve quality and the reliability of the antenna will have less down time.''

Telecommunications system leader Peter Ilott said shutting down the Australian 70-metre antenna for seven months would not stop or negatively impact on any programs. ''It will be pretty much business as usual. We can use the 34-metre antennas,'' Dr Ilott said.

''The nice thing about the fact that we use orbiters as relay for our data is that orbiters have very large antennas compared to the lander. We can't put a big antenna on the lander and the orbiters can talk to the 34-metre antennas pretty much no problem. It decreases the data rate that we can transfer the data at but in general it won't affect us.''

During the refurbishment, the reflector surface of the dish will also be painted with a special paint from the United States.

NASA Voyager-1 and Humankind set to cross the final frontier to Interstellar Space

It will be one of the most important milestones in human history as, for the first time, an ambassador for humankind moves beyond the confines and protection of our solar system.

NASA scientists are preparing for the moment, any day now, when the first of two spacecraft launched in the late 1970s crosses the invisible boundary that marks the start of "interstellar space".

Already they have passed some of the furthest planets of the solar system, transmitting spectacular images of the worlds that circle the sun.

This artist's concept by NASA/JPL-Caltech shows Voyager 1 and Voyager 2 at the edge of the solar system. 

The Voyager 1 probe, which is now about 17.7 billion kilometres from Earth, has entered a "transition zone" at the edge of the solar system, scientists say.  

Photo: AFP/NASA/JPL-Caltech

Voyager 1 is about 11 billion miles from Earth and hurtling away at a rate of 13 kilometres a second. Its sister craft, Voyager 2, is not far behind.

Each carries an array of instruments to gather information about outer space - and also a gold-plated copper disc with sounds and images intended to convey a sample of what life is like on Earth should they ever encounter other intelligent life.

Should an alien ever find one of the craft, the first human to whom they will be introduced - assuming they can decode the technology - will be Ann Druyan, now 63, an author and television producer who fell in love with the US astronomer Dr Carl Sagan while they were working on the Voyager mission.

A file photo released by NASA in 1970 shows the golden record on Voyager 1, launched on September 5, 1977, with a cartridge and a needle to play it.  

Photo: AFP/NASA

Nasa Voyager 1 & 2 Breaks through Heliosphere - Video

This video drops in on mission control for NASA's Voyager spacecraft as Voyager 1 sends back data from the far reaches of our solar system.

Credit: NASA/JPL-Caltech › Voyager's mission site

Voyager 1 & 2: The Interstellar Mission

The twin Voyager 1 and 2 spacecraft continue exploring where nothing from Earth has flown before.

In the 34th year after their 1977 launches, they each are much farther away from Earth and the Sun than Pluto.

Voyager 1 and 2 are now in the "Heliosheath" - the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar gas.

Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network (DSN).


The primary mission was the exploration of Jupiter and Saturn.

After making a string of discoveries there, such as recording active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings, the mission was extended.

Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets.

The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain and beyond.

Mission Objective

The mission objective of the Voyager Interstellar Mission (VIM) is to extend the NASA exploration of the solar system beyond the neighbourhood of the outer planets to the outer limits of the Sun's sphere of influence, and possibly beyond.

This extended mission is continuing to characterize the outer solar system environment and search for the heliopause boundary, the outer limits of the Sun's magnetic field and outward flow of the solar wind.

Penetration of the heliopause boundary between the solar wind and the interstellar medium will allow measurements to be made of the interstellar fields, particles and waves unaffected by the solar wind.