About a year ago, NASA's Voyager 2 space agency, NASA, left our solar system. Several reports recently published in by Nature Astronomy describe the basic scientific discoveries of a spacecraft.
NASA says that Voyager 2's mission has led to new discoveries about the boundary that separates our solar system from interstellar space. "Interstellar" means "between the stars." But scientists define interstellar space as the place where a continuous flow of sunlight from material and a magnetic field cease to affect its surroundings.
Interstellar space is estimated to be about 18 billion kilometers from Earth.  What did the spacecraft find?
The project's researchers say that Voyager 2's scientific instruments have discovered unexpected differences in plasma density, a collection of charged particles existing in the solar system.
NASA also says that new research reports confirm that both Voyager 1 and Voyager 2 appear to be in a transitional zone just beyond the heliosphere. The heliosphere is a protected bubble that protects our solar system. It is created by the solar wind formed by charged particles. The boundary of the solar system – the place where the solar wind ends and the interstellar space begins, is called heliopause.
The team reports that Voyager 2 data suggests that heliopause seems much thinner than expected.
Edward Stone is a physicist at the California Institute of Technology and head of the Voyager program. Stone told reporters the findings were "a very exciting time for us."
He stated in a statement that the Voyager 2 mission provided details of how the sun interacts with materials that fill most of the space between stars along the Milky Way.
Researchers say Voyager 2 also confirms the existence of a "magnetic barrier" at the outer edge of the heliosphere that was predicted by Voyager 1. Theory
"Without this new data from Voyager 2, we would not know whether what we see with Voyager 1 was characteristic of the entire heliosphere, or specific only of the location and time when it passed, "said Stone.  Leonard Burlaga is a scientist at the NASA Goddard Space Flight Center and a lead researcher in one of the He told the French news agency AFP that there were some surprises. " Contrary to all expectations and predictions, the direction of the magnetic field did not change when Voyager 2 crossed the heliopause," he says.
The spacecraft also collects information about incoming cosmic rays – particles that strike the Earth from anywhere outside its atmosphere – data shows that the rays are amplified as Voyager researchers approach the heliopause.
Origin of the Voyager Spacecraft
Voyager 2 was one of two researchers launched by NASA back in the summer of 1977. The other was Voyager 1. Both spacecraft were first designed to carry flight studies of Jupiter and Saturn.
Later, Voyager 2 completed the first ever close observations of Uranus and Neptune.
Then the two spacecraft embarked on a new mission to explore the sun's edge regions.
The two voyagers – first built to last only five years – have long gone beyond their operational lives. But after 42 years in action, both are expected to disappear and remain silent within five years.
means they will disappear. Bill Kurt, a researcher at the University of Iowa and co-author of one of the research reports, said he expects space researchers to transcend Earth. "They have been in their own orbit around the galaxy for five billion years or longer," he said. "And the likelihood of them encountering something is almost zero. "
I'm Brian Lynn.
Brian Lynn writes this story for VOA Learning English, based on reports from NASA, Reuters and Agence France-Presse. Kelly Jean Kelly was the editor.
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