A blue dot in a cosmic ocean: Radio signal from Nasa's Voyager 1 as it travels outside our solar system is seen from Earth for the first time



Voyager 1 was launched in 1977 and has now left our solar system



Scientists can't see the spacecraft but they can detect its radio light

Powerful radio telescopes picked up the signal which looks like a blue speck

Scientists claim Voyager 1 entered interstellar space more than a year ago

Study claims Voyager 1 left heliosphere around August 25, 2012

Voyager 1 is now the first mission to explore interstellar space



This incredible photo shows radio signals glowing blue from the spacecraft Voyager 1 nearly 12 billion miles away.



Scientists can't actually see the spacecraft but they can detect its radio light.

They used the Very Long Baseline Array (VLBA) a network of powerful radio telescopes to pick up

the signal which looks like a blue speck.



It is believed this image was taken on February 21 this year.



Suzanne Dodd, Voyager's project manager at NASA's Jet Propulsion Laboratory in Pasadena,

California, said: 'This image represents the Voyager radio signal as seen by the world's most sensitive ground-based telescope.

Outer space: The Very Long Baseline Array (VLBA), a network of radio telescopes operated by the National Radio Astronomy Observatory, spotted the signal of NASA's Voyager 1 spacecraft from 11.5 billion miles away

'It's just a speck in amongst a sea of darkness.'

Earlier today a sound recording was sent back to Earth from the spacecraft as it crossed a new frontier becoming the first spacecraft to ever leave the solar system.



The rising tones NASA observed are made by the vibration of dense plasma or ionised gas and were captured by the probe's plasma wave instrument.



Speaking in a news conference, Don Gurnett, principle investigator for the Voyager plasma wave investigation , said: ' W hen you hear this recording, please recognise that this is an historic event. It's the first time that we've ever made a recording of sounds in interstellar space.'



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A massive 36 years of scientific data generated by Nasa's Voyager spacecraft has been transformed into a powerful piece of orchestral music. Voyager 1's current mission (illustrated) along with Voyager 2, is to explore the outermost edge of the Sun's domain and beyond

A massive 36 years of scientific data generated by Nasa's Voyager spacecraft has been transformed into a powerful piece of orchestral music. Voyager 1's current mission (illustrated) along with Voyager 2, is to explore the outermost edge of the Sun's domain and beyond

NASA officials added: 'There were two times the instrument heard these vibrations: October to November 2012 and April to May 2013.



'Scientists noticed that each occurrence involved a rising tone. The dashed line indicates that the rising tones follow the same slope. This means a continuously increasing density.'

A team still stays in contact with the two Voyager spacecraft every day but Voyager 1's extreme distance, currently around 12 billion miles from Earth, means a message takes 17 hours to reach us.



Thirty-six years after it was launched from Earth on a tour of the outer planets, the plutonium-powered probe is more than 11 1/2 billion miles from the sun, cruising through what scientists call interstellar space — the vast, cold emptiness between the stars, the space agency said.

Voyager 1 actually made its exit more than a year ago, according to NASA. But it's not as if there's a dotted boundary line out there or a signpost, and it was not until recently that the space agency had the evidence to convince it of what an outside research team had claimed last month: that the spacecraft had finally plowed through the hot plasma bubble surrounding the planets and escaped the sun's influence.

While some scientists said they remain unconvinced, NASA celebrated.

'It's a milestone and the beginning of a new journey,' said mission chief scientist Ed Stone at NASA's Jet Propulsion Laboratory in Pasadena.

Voyager 1 will now study exotic particles and other phenomena in a never-before-explored part of the universe and radio the data back to Earth, where the Voyager team awaits the starship's discoveries.

The interstellar ambassador also carries a gold-plated disc containing multicultural greetings, songs and photos, just in case it bumps into an intelligent species.

This artist's concept shows NASA's two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun VOYAGER'S INTERSTELLAR MISSION

It is 36 years since the twin Voyager 1 and 2 spacecraft were launched and the pair continue to explore 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. Voyager 1's odyssey began in 1977 when the spacecraft and its twin, Voyager 2, were launched on a tour of the gas giant planets of the solar system. After beaming back dazzling postcard views of Jupiter's giant red spot and Saturn's shimmering rings, Voyager 2 hopscotched to Uranus and Neptune. Meanwhile, Voyager 1 used Saturn as a gravitational slingshot to power itself past Pluto. Voyager 1, which is about the size of a subcompact car, carries instruments that study magnetic fields, cosmic rays and solar wind. Last year, scientists monitoring Voyager 1 noticed strange happenings that suggested the spacecraft had broken through: Charged particles streaming from the sun suddenly vanished. At the same time, there was a spike in galactic cosmic rays bursting in from the outside. Since there was no detectable change in the direction of the magnetic field lines, the team assumed the far-flung craft was still in the heliosphere, or the vast bubble of charged particles around the sun

Voyager is bathed in solar wind from the southern hemisphere flowing northward

The Voyager team patiently waited for a change in magnetic field direction — thought to be the telltale sign of a cosmic border crossing. But in the meantime, a chance solar eruption caused the space around Voyager 1 to echo like a bell last spring and provided the scientists with the data they needed, convincing them the boundary had been crossed in August of last year.

'It took us 10 seconds to realize we were in interstellar space,' said Don Gurnett, a Voyager scientist at the University of Iowa who led the new research, published online in the journal Science.

The new observations are fascinating, but 'it's premature to judge,' said Lennard Fisk, a space science professor at the University of Michigan and former NASA associate administrator who was not part of the team. 'Can we wait a little while longer? Maybe this picture will clear up the farther we go.'

Voyager 1 is capable of returning scientific data from a full range of instruments, with adequate electrical power and attitude control propellant to keep operating until 2020.

What bothers Fisk is the absence of a change in magnetic field direction.

Harvard astrophysicist Jonathan McDowell was more blunt: 'I'm actually not going to believe it for another year or two until it's been solidly outside for a while.'

While Voyager 1 may have left the solar system as most people understand it, it still has thousands of years to go before bidding adieu to the last icy bodies that make up our neighborhood.

Voyager 2 trails behind at 9 1/2 billion miles from the sun. It may take another three years before Voyager 2 joins its twin on the other side. Eventually, the Voyagers will run out of nuclear fuel and will have to power down their instruments, perhaps by 2025.