The Parkes Radio Telescope is once again playing a major role in an incredibly rare event mission scientists at NASA have been anticipating for decades.
NASA’s Voyager 2 entered interstellar space (the space between stars) approximately 18 billion kilometres from Earth on 5th November, 41 years after its launch. “I was in Year 9 and clearly remember it,” said John Sarkissian, CSIRO Operations Scientist at the Parkes Radio Telescope.
“It is a really exciting time and such a valuable scientific moment,” said John who has spent many 14-hour days at The Dish since last month to ensure everything runs smoothly as the Parkes antennae tracks Voyager 2 for 11 hours every day to receive real time data for NASA.
Although Voyager 2 is the second spacecraft to exit the heliosphere, a protective bubble created by our Sun, after its twin Voyager 1, John explains that not all instruments were functioning on Voyager 1 at the time. “That is why this is such a major project as we will not have this opportunity again for decades. It took 41 years and we cannot lose this opportunity.”
John’s excitement is apparent as he explains that it is the first time that scientists are able to sample interstellar space. “We are getting back incredibly valuable and detailed information and learning a lot about
what it is actually like. Before we could only guess, but this time we have a man-made instrument sending back information!”
As Voyager 2 is so far from Earth, 120 times further from the Sun
than earth is, the signal takes 16.5 hours to reach Earth and is incredibly
weak. “That is why you need very big antennae to receive
the signal, and as Voyager 2 is very far south and below the horizon
for telescopes in the northern hemisphere, the Parkes Radio Telescope
and Canberra Deep Space Communication Complex are
the only facilities in the world capable of having contact with the
spacecraft.”
Parkes is doing the bulk of the tracking on a daily basis as Voyager
2 isn’t able to record its data on board, and transmits it directly from the instruments back to Earth.
CSIRO Chief Executive Dr Larry Marshall said: “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.
“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 fifty years ago, the Apollo 11 Moon landing.”
It is the fourth time Parkes is helping to track the Voyager mission. 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.
By Maggi Barnard