For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.
On Monday NASA announced that Voyager 2 probe has reached interstellar space. NASA’s Voyager 2 was launched in 1977 and explored the solar system. It was launched a week before Voyager 1 but its trajectory took it on a longer route through the solar system. The first human-made object to exit our solar system was Voyager 1 which reached the interstellar space in 2012.
According to NASA, “Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light travelling from the Sun takes about eight minutes to reach Earth.”
For the second time in history, a human-made object has reached the space between the stars. Now slightly more than 11 billion miles (18 bil. km) from Earth, @NASAVoyager 2 has now left the Sun’s protective bubble & is flying in interstellar space: https://t.co/zRnhiaJqGS #AGU18 pic.twitter.com/Zzncki4GKB
— NASA (@NASA) December 10, 2018
NASA revealed that the probe crossed the outer edge of the heliosphere which is also known as heliopause on November 5.
According to NASA, “Working on Voyager makes me feel like an explorer because everything we’re seeing is new,” said John Richardson, principal investigator for the PLS instrument and a principal research scientist at the Massachusetts Institute of Technology in Cambridge. “Even though Voyager 1 crossed the heliopause in 2012, it did so at a different place and a different time, and without the PLS data. So we’re still seeing things that no one has seen before.”
In addition to the plasma data, Voyager’s science team members have seen evidence from three other onboard instruments – the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer – that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager’s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is travelling.
“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.
Together, the two Voyagers provide a detailed glimpse of how our heliosphere interacts with the constant interstellar wind flowing from beyond. Their observations complement data from NASA’s Interstellar Boundary Explorer (IBEX), a mission that is remote sensing that boundary. NASA also is preparing an additional mission – the upcoming Interstellar Mapping and Acceleration Probe (IMAP), due to launch in 2024 – to capitalize on the Voyagers’ observations.
“Voyager has a very special place for us in our heliophysics fleet,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. “Our studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun’s influence gives us an unprecedented glimpse of truly uncharted territory.”
NASA Press Release