The Cassini spacecraft at Saturn recently observed a light show on the planet’s southern hemisphere: auroras, glittering in the gaseous atmosphere.
Similar to auroras on Earth, Saturn’s auroras are formed by charged particles raining down on the planet, colliding with the atmosphere and creating light, according to a statement from NASA. The charged particles come from the solar wind, a steady stream of material emanating from the sun.
A video from NASA shows the “ghostly curtains of light” billowing through Saturn’s atmosphere. The black-and-white video was captured on July 20, in visible light. The technicolor photograph that serves as the backdrop in the video was taken in 2008 in near-infrared light, and is false-colored to highlight the ring of auroras around the planet’s pole. [Cassini’s ‘Grand Finale’ at Saturn: NASA’s Plan in Pictures ]
Cassini is moving around Saturn, but kept its gaze fixed on the same point during these observations, which lasted more than an hour, according to the statement .
A large, false-color image of Saturn’s auroras taken by the Cassini probe in 2008 was compared with a visible-light image taken in 2017.
Credit: NASA/JPL-Caltech/Space Science Institute
“Some of the stars seem to make a slight turn to the right just before disappearing,” officials said in the statement. “This effect is due to refraction — the starlight gets bent as it passes through the atmosphere, which acts as a lens. Some of the stars seem to make a slight turn to the right just before disappearing. Random bright specks and streaks appearing from frame to frame are due to charged particles and cosmic rays hitting the camera detector.”
This is not the first time scientists have spotted auroras on Saturn. They were discovered by the Pioneer 11 probe, according to NASA , and have been studied by the Voyager probes, the Hubble Space Telescope and Cassini .
The Cassini spacecraft, now at the end of its mission, is headed for a dive into Saturn’s atmosphere on Sept. 15.