Now, scientists have shared the initial science gained by Voyager 2's historic crossing. In a new study, scientists have confirmed that the spacecraft is now outside the bubble-shaped region created by the sun's wind, known as the heliosphere. Ultimately, this solar blanket has a crucial impact on the formation and evolution of planetary systems by acting as a huge shield that blocks galactic radiation.
The data transmitted by Voyager 2 was analysed by a large team of physicists, and their findings were published in five papers in Nature Astronomy on Monday this week. The boundary between the heliosphere and outside space is called the heliopause. Just beyond the heliopause Voyager 2 discovered a boundary layer, where solar winds leak into space and interact with interstellar winds.
Voyager-2 entered the ISM 119.7 astronomical units (AU), 11 billion miles from the Sun. Scientists are sure of this since the plasma wave instrument onboard the spacecraft has measured a significant increase in plasma density, up from the hot, low-density plasma characteristic of the solar wind. "The boundary layer we saw at Voyager 2 we couldn't see at Voyager 1 because we didn't have a working plasma instrument, so we couldn't see the density go up and the temperature go up", explained heliophysicist John Richardson of the Massachusetts Institute of Technology in Cambridge. They are established through NASA's Deep Space Network. We had no quantitative idea of how big this bubble is that the sun creates around itself with its supersonic solar wind, made of ionized plasma, which is speeding away from the sun in all directions.
Data from the instrument on Voyager 2 also gives additional clues to the thickness of the heliosheath, the outer region of the heliosphere and the point where the solar wind piles up against the approaching wind in interstellar space, which Gurnett likens to the effect of a snowplow on a city street. The probe was launched from earth 16 days before its twin spacecraft, Voyager 1 but entered the interstellar space more than six years after Voyager 1 because of its slower trajectory. Additionally, interstellar space contains cosmic rays, particles accelerated by exploding stars. For example, Voyager 2 detected a continuous change in magnetic field directions as it crossed into the ISM, whereas Voyager 1 did not. "We will see a transition from the magnetic field inside to a different magnetic field outside, and we continue to have surprises compared to what we had expected". "We show with Voyager 2 - and previously with Voyager 1 - that there's a distinct boundary out there". "That's a characteristic of fluids, which oftentimes form very sharp boundaries", says Gurnett.
The interaction between the sun and interstellar space is also intriguing to the scientists.More news: Sir Chris Hoy to race for Red Bull Bahrain Virtual Grand Prix
"As it moves through the interstellar medium" - the vast expanses of space between stellar fiefdoms - "there's a wave in front, just as with the bow of a ship", Stone told journalists by phone.
All of the early insight gained from this crossing is providing a complex picture of what happens in between the sun and interstellar space. This knowledge could be applied to all the stars astronomers study, because they believe other stars likely possess the same features.
But now Voyager 2 has crossed this barrier that separates the solar system from the rest of the galaxy.
Built to last five years, Voyager 1 and Voyager 2 set out to explore the solar system's outer planets. The new Voyager 2 data, like the Voyager 1 data before it, shows how CMEs propagate past the heliopause and lower the amount of cosmic rays beyond the bubble. The heliosphere is 11 billion miles from Earth, which is well beyond Pluto's orbit. After that 1989 flyby, the two probes had completed their primary objective, but they were far from done.
Over time, power system efficiency has decreased, and the generators produce 40% less than they did at the time of launch.More news: Gas prices fall below $ 2 per gallon in 12 states
Still, the observations of the heliopause really are part of the last hurrah for both spacecraft. Engineers did the same thing with thrusters on Voyager 1 in 2017.
The heliosphere is somewhat leaky, revealed Voyager's particle instruments. It's also using more power, so engineers turned off a heater for the Cosmic Ray Subsystem. This was more clearly confirmed by Voyager 2 spacecraft.
The data gathered by the probes has helped inform NASA's Interstellar Mapping and Acceleration Probe, scheduled to launch in 2024.
"The two Voyagers will outlast Earth", said Kurth.More news: Huge package of help for auto dealers and businesses unveiled by chancellor