NASA's Voyager 2 spacecraft has become only the second spacecraft to enter interstellar space and the Parkes Radio Telescope was right there listening.
NASA announced on Tuesday morning at the Parkes Dish that Voyager 2 had left the “heliosphere” – the protective shroud cast by the sun around our solar system – that’s about 18 billion kilometres away from earth and took 41 years of travelling.
CSIRO's iconic Parkes Radio Telescope and the huge dishes at Canberra’s Deep Space Communications Complex (CDSCC) confirmed the craft’s escape from local space.
Voyager 2's milestone, becoming the second human-built craft to reach interstellar space, was actually reached on November 5, but it took several weeks for NASA to receive the unique and historic data and confirm the findings.
The Parkes telescope will continue to receive data into early 2019.
Because of Voyager 2's location and distance from earth, CDSCC and the Parkes telescope are the only facilities in the world that are capable of having contact with the spacecraft.
Voyager 2 isn't able to record its data on board – it transmits it directly from the instruments back to earth, making it essential to receive as much of this vital data as possible.
Our solar system is blanketed by "solar wind" – an invisible stream of particles emitted by the sun. This wind repulses the "interstellar wind", a stream of dangerous cosmic high-energy particles that race towards us from deep space.
As Voyager 2 headed toward the solar system’s boundary, an instrument on board has been tracking a fall in the number of particles emitted by the sun that hit the craft.
That dropped off as interstellar space was reached. At the same time, galactic cosmic ray intensity also increased, showing the craft was outside the sun’s protection.
CSIRO Chief Executive Dr Larry Marshall said CSIRO was here to solve the greatest challenges with science.
“We're proud to help NASA solve the scientific challenge of capturing this once-in-a-lifetime opportunity as Voyager 2 ventures into interstellar space,” he said.
“Our team at Parkes has partnered with NASA on some of humanity's most momentous steps in space, including the landing of the Mars Rover Curiosity and, almost 50 years ago, the Apollo 11 Moon landing.
“Our long-standing relationship with NASA stretches back more than 50 years, creating breakthrough solutions from science, and fuelled by our shared ambition to push the boundaries of exploration to benefit life back on earth.”
CSIRO Director of Astronomy and Space Science Dr Douglas Bock explained how the additional support from Parkes would track Voyager 2.
“The Canberra Deep Space Communication Complex, which CSIRO operates on behalf of NASA, has been providing command, telemetry and control for the twin Voyager spacecraft since their launch in 1977,” he said.
“NASA has engaged our 64-metre Parkes Radio Telescope to ‘combine forces' with CDSCC's 70-metre antenna, Deep Space Station 43 (DSS43), to capture as much scientifically valuable data as possible during this critical period.
“The Parkes telescope will be tracking Voyager 2 for 11 hours a day while the spacecraft is observable from Parkes.
“CDSCC's DSS43 will also track Voyager 2 for a number of hours both before and after Parkes, expanding the available observation time.
“This is a highlight of CSIRO's decades' worth of experience operating large, complex spacecraft tracking and radio astronomy infrastructure.”
Voyager 1 crossed into interstellar space in 2012, while Voyager 2 has been on a different trajectory through our solar system.
On its journey, Voyager 2 has famously flown past Jupiter (in 1979), Saturn (in 1981), Uranus (in 1986) and Neptune (in 1989), returning valuable images and data.
The Parkes telescope is part of the Breakthrough Listen program, a global initiative to seek signs of technological signatures in the universe.