Just outside of our solar system, onboard the Voyager space probes, sits the Golden Record, a "message in a bottle" filled with songs and sounds from life on earth.

Key points: The Golden Records onboard the probes are now both outside of our solar system

The Golden Records onboard the probes are now both outside of our solar system Of just 27 songs, designed to show aliens what Earth is like, two are from the Pacific islands

Of just 27 songs, designed to show aliens what Earth is like, two are from the Pacific islands The records also contain 55 greetings in different languages and a collection of sounds

After blasting off earth in 1977, Voyager 1 left the solar system in 2012, and Voyager 2 has just gone interstellar, heading beyond our solar system.

Sorry, this audio has expired Pacific music in space

The probes both have a special cargo on board — a copy each of a copper-plated polygraph dubbed the Golden Record, containing 27 songs from all corners of the globe.

The record began a trend of sending physical artefacts into space, including diamonds, an advertisement for Doritos, and more recently 50,000 poems read by users on Chinese social media platform WeChat from around the world.

A 'message in a bottle' to possible alien life

NASA's Voyager 1 and Voyager 2 probes are positioned just outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. ( NASA/JPL-Caltech )

As the second probe left our solar system, family members of those who played the original traditional songs from the Pacific told the ABC they are "very, very happy" that pieces from their culture may be the first thing possible alien life could hear.

The probes' main purpose is to collect data and photographs from space and send them back to earth, but in 1977, NASA asked famous astronomer Carl Sagan to create a bonus: "Some message for a possible extra-terrestrial civilisation".

Mr Sagan and a group of others came up with the idea of The Sounds of Earth, widely known as the Golden Record, which writer and science communicator Ann Druyan then curated, leading the hunt for music and sounds for the disc.

This pale blue dot, less than a pixel in size, was Voyager 1's view of Earth. ( Supplied: NASA/JPL )

"This was our chance to create a kind of Noah's ark of human culture," Ms Druyan, who married Mr Sagan four years after the probes left earth, told Time Magazine in 2017.

Inside each Voyager vessel, the gold-plated and copper-etched records sit in aluminium cases, with 27 musical items, 55 greetings in different languages, and a collection of sounds that include a kiss, a dog barking, a whale song, and brain waves.

The capsule also includes a polygraph needle and etched instructions for how a possible alien might play the music.

Dr Glen Nagle from the Canberra Deep Space Communication Complex, which receives data from the probes, told the ABC the record was "a little time capsule".

"[It was] a message in a bottle that we were going to throw out into a giant cosmic ocean of the universe, to basically say 'this is who created this spacecraft, this is who we are, this is our place in the universe, and if you're there, learn about us, and maybe come and see us if you're curious like us'."

The songs include famous tracks like Chuck Berry's Johnny B Goode, and all-but-unknown traditional music from places like Milingimbi in Australia's Arnhem Land and villages in Papua New Guinea and Solomon Islands.

'Part of us is in space'

Sergeant William "Billy" Bennett was a radio operator in World War II before becoming one of the faces of the Solomon Islands Broadcasting Service. ( Australian War Memorial: H A Mackenzie )

NASA lists one of the songs as "panpipes, collected by the Solomon Islands Broadcasting Service", but the ABC has spoken to family members of the original panpipe group who confirmed the musicians were from the small village of Oroha, in the island province of Malaita.

There is no current data for how many people speak the Oroha language, but estimates in the past decade have put that number at only a few hundred people — and the particular style of music on the recording belongs just to them.

There were eight men playing the pipes for the recording and Sam Matanai, the nephew of one of the men, Isaac Houmawai, said the song was traditionally reserved for special occasions like feasts.

"We are very, very happy that our music, part of us, is in space," Mr Matanai told the ABC shortly after Voyager 2 had gone interstellar.

The song was recorded by William Bennett, a Solomon Islander who helped found the Solomon Islands Broadcasting Service after fighting in World War II.

Mr Matanai said it was understood a copy made its way onto the Golden Record after being taken back to the UK by a visiting journalist.

The original recording now sits in the archive of what is now the Solomon Islands Broadcasting Corporation, and current workers at the newsroom told the ABC they were happy to know it was there.

While Mr Matanai said there was pride in knowing his family's song was now floating just outside the solar system, there was even more pride in knowing his culture would live on in his village.

"We can pass this to other generations in [the] future, because we learned this very well, and we can dance this very well, we can blow this very well. This panpipe was ours, blown by our ancestors."

'Something that represents the earth'

Sorry, this video has expired Members of NASA's Voyager project explain why the probes are so significant. (Video: NASA)

The 27 songs came from all over the world, including from the Nyaura clan, from the Papua New Guinean village of Kandingei in what is now East Sepik Province.

As with the song from Solomon Islands, the detail from NASA is scant, only referencing the song as "men's house song, recorded by Robert MacLennan".

A front-page story in Papua New Guinea's The National newspaper on May 10, 1995 details ethnomusicologist and doctor Robert MacLennan (R) handing over the Golden Record to then-prime minister of PNG Sir Julius Chan (L). ( Supplied )

"The recording that was chosen was performed by two different men on long flutes that are distinctive of the area, associated with men's initiation and men's houses," acting director of the Institute of Papua New Guinea studies in Port Moresby, Dr Don Niles, told the ABC.

Men's houses are less common in the modern era, but are men-only spaces used for initiation, ceremonies and discussion.

Dr Niles was a friend of Robert MacLennan, an Australian doctor who spent years in PNG before he died in 2013 — and according to Dr Niles, Dr MacLennan made hundreds of recordings of traditional music during his life.

"He very much fell in love with the place, with the music," Dr Niles said.

Dr Niles said Dr MacLennan was "always willing to share" the recordings with other people, but that the full story of how the music left PNG and made it onto the Golden Record was one Dr Niles was always "put off hearing" as he was waiting for the right moment.

"Unfortunately that never happened, as Bob died a few years ago," he said.

Since leaving Earth in 1977, the Voyager probes have collected a world of data and information about life in our solar system and beyond.

And in 2017, the record was made commercially available for the first time in decades, and even won a Grammy music award that year.

But Dr Niles said the record was much more than "just about Nyaura clan, about East Sepik Province, about Papua New Guinea".

"This is something that represents the earth, and its creations," he said.