On Wednesday, April 26, the Cassini spacecraft did something extraordinary: It slipped through the gap between Saturn and its rings, becoming the first spacecraft ever to explore this region.
The trip took it closer to the top of Saturn’s atmosphere than any spacecraft had been before. And, yes, there are pictures.
On Thursday, NASA released these unprocessed images from Cassini. (Unprocessed means dust and other photographic artifacts are still in the shot.) What they represent is extraordinary: photographs taken just 1,900 miles above Saturn’s atmosphere, while traveling at a speed of 77,000 mph relative to Saturn.
Here you can see a cyclone spinning in Saturn’s atmosphere.
These two images show banding and cloud features in Saturn’s atmosphere.
Not bad at all for a 20-year-old camera 800 million-plus miles away.
Cassini’s camera didn’t have its color filters turned on for this pass, so we won’t be seeing close-up, full-color images. “We were moving too fast to be able to take multiple filters over the same place on the planet,” Preston Dyches, a NASA spokesperson, says. “When the spacecraft is really close to just Saturn like that, it's not possible to remain pointed at the same location long enough to snap a red, green, and blue Image.” (NASA usually can combine the red, green, and blue images for a full-color representation.)
In any case, it’s still thrilling to get shots this close.
The images come to us from Cassini’s “grand finale” — a series of 22 orbits bringing the spacecraft inside the 1,500-mile-wide gap between Saturn and its rings. The photos are only a small part of the mission. Another objective is to take new measurements to better determine the total mass of Saturn’s rings. NASA already knows the mass of Saturn plus its rings. Getting closer to the planet will allow Cassini to take its mass without factoring in the rings. That information will help scientists better understand how the rings formed (which in turn can help them understand how all the planets formed from rings of material around the sun).
After the 22 orbits, Cassini will crash into Saturn’s atmosphere. Read more about Cassini’s “grand finale” here.