Her Voyager 1 NASA, currently the most distant spacecraft from Earth, came out of our solar system a decade ago, surpassing 11 billion miles from Earth and traversing space. Since then, it is 3 billion miles away and continues to send data to Earth, allowing scientists to explore space beyond our own solar system.
In a publication in the magazine Nature Astronomy On Monday, researchers looked at data from the system Plasma Wave of Voyager 1 on its journey, but especially since it crossed the boundaries of our solar system.
The boundary between the solar system and space is an "end" where the influence of the sun disappears and the interstellar medium begins. The medium is typically described as empty, deserted, and dark, but the PWS in Voyager 1 detected a low, continuous sound on its detector, like drops of space rain falling gently on a window. These drops are plasma waves or interstellar gas.
"We noticed the faint, persistent hum of the interstellar gas", Said the Stella Koch Ocker, a doctoral student at Cornell University who leads the research. "It is very faint and monotonous because it is in a narrow frequency band."
For nearly a billion miles, Voyager 1 could hear the monotonous roar, and researchers believe that these weak plasma waves differ from other detections made in the vast absence of interstellar space. For example, sometimes the sun explodes, releasing particles into space. The explosions have a characteristic sound that o James Cordes, an astronomer in Cornell, resembles a lightning bolt.
These explosions were once used to determine the density of interstellar plasma, but this low, steady buzz shows that Voyager collects a lot of information that has nothing to do with solar explosions.
"We now know that we do not need a sun-related random event to measure interstellar plasmaSaid Shami Chatterjee, a Cornell researcher and co-author of the book.
Future interstellar space missions will help clarify what is happening out there and NASA has plans for a such a mission, the 2030s.
Voyager 1 also has a brother detector, Voyager 2, which travels outside the solar system in a different direction. In 2020, while upgrades were made to one of the Deep Space Network communication boards, Voyager II wandered into space alone. In November, a signal was sent to the spacecraft for the first time in eight months and fortunately a response was received.
The two ships were launched in August and September 1977 and have since moved away from Earth. Voyager 2 left the solar system in 2018 at a completely different point from Voyager 1. The transit allowed researchers to further explore the sunspot, the giant, protective solar wind bubble that encloses our solar system.