Voyager 1, which is the farthest human-made object from Earth and the first to enter interstellar space, has been detecting a “faint, persistent hum” that scientists have attributed to interstellar gas.
Phys.org, citing research published in Nature Astronomy, reported that the spacecraft’s Plasma Wave System has picked up a “persistent signature produced by the tenuous near-vacuum of space.”
James Cordes, a professor of astronomy at Cornell University, reportedly described the sound as a “quiet or gentle rain.”
“In the case of a solar outburst, it’s like detecting a lightning burst in a thunderstorm and then it’s back to a gentle rain,” he said.
Stella Koch Ocker, a doctoral student at the university, who lead the research, said, “We’re detecting the faint, persistent hum of interstellar gas. It’s very faint and monotone, because it is in a narrow frequency bandwidth.”
Voyager 1′s odyssey began in 1977 when the spacecraft and its twin, Voyager 2, were launched on a tour of the gas giant planets of the solar system.
After beaming back dazzling postcard views of Jupiter’s giant red spot and Saturn’s shimmering rings, Voyager 2 hopscotched to Uranus and Neptune. Meanwhile, Voyager 1 used Saturn as a gravitational slingshot to power itself past Pluto.
It is now about 15 billion miles from Earth.
Voyager 1 is about the size of a subcompact car and carries instruments that study magnetic fields, cosmic rays and solar wind.