Voyager Beams Back Proof of Neptune, Triton Auroras
Voyager 2 data confirm the existence of flickering auroral displays in the atmospheres of the ringed planet Neptune and its baffling volcanic moon Triton--the coldest world ever studied, scientists announced today.
University of Arizona researcher Roger Yelle told a news conference that analysis of data beamed back earlier in the Voyager 2 Neptune encounter indicates the temperature of Triton’s lower atmosphere is 400 degrees below zero.
“The temperature of the atmosphere is 37 degrees (above absolute zero), which is equivalent to 400 degrees Fahrenheit below zero,” he said. “Simply put, Triton appears to be the coldest object in the solar system that we’ve visited so far.”
He said both Triton and Neptune have auroras--the flickering displays produced by the interaction of electrically charged particles and a planet’s magnetic field--although the phenomenon on Neptune is complex and difficult to understand.
The latest data returned by Voyager’s ultraviolet light sensor revealed auroras--somewhat like Earth’s northern and southern lights--in several places in Neptune’s skies and over much of the day side of Triton, Yelle said.
The auroras occur at odd places because of Neptune’s tilted magnetic field, which is a steep 50 degrees from the planet’s rotation axis, Yelle said.
Voyager 2 is now cruising away from the solar system on an endless space odyssey. Scientists are discussing the possibility of using the spacecraft’s cameras to take a wide-angle shot of the whole solar system at some point in a first-of-a-kind portrait of humanity’s home in the cosmos.
