Cassini Captures Ghostly Dance of Saturn's Northern Lights (w/ Video)

Nov 24, 2009

(PhysOrg.com) -- In the first video showing the auroras above the northern latitudes of Saturn, Cassini has spotted the tallest known "northern lights" in the solar system, flickering in shape and brightness high above the ringed planet.

The new video reveals changes in Saturn's every few minutes, in high resolution, with three dimensions. The images show a previously unseen vertical profile to the auroras, which ripple in the video like tall curtains. These curtains reach more than 1,200 kilometers (750 miles) above the edge of the planet's .

Auroras occur on Earth, Jupiter, Saturn and a few other planets, and the new images will help scientists better understand how they are generated.

This video is not supported by your browser at this time.
Credit: NASA/JPL/Space Science Institute

"The auroras have put on a dazzling show, shape-shifting rapidly and exposing curtains that we suspected were there, but hadn't seen on Saturn before," said Andrew Ingersoll of the California Institute of Technology in Pasadena, who is a member of the Cassini imaging team that processed the new video. "Seeing these things on another planet helps us understand them a little better when we see them on Earth."

Auroras appear mostly in the high latitudes near a planet's magnetic poles. When charged particles from the magnetosphere -- the surrounding a planet -- plunge into the planet's upper atmosphere, they cause the atmosphere to glow. The curtain shapes show the paths that these charged particles take as they flow along the lines of the between the magnetosphere and the uppermost part of the atmosphere.

The height of the curtains on Saturn exposes a key difference between Saturn's atmosphere and our own, Ingersoll said. While Earth's atmosphere has a lot of oxygen and nitrogen, Saturn's atmosphere is composed primarily of hydrogen. Because hydrogen is very light, the atmosphere and auroras reach far out from Saturn. Earth's auroras tend to flare only about 100 to 500 kilometers (60 to 300 miles) above the surface.

The speed of the auroral changes in the video is comparable to some of those on Earth, but scientists are still working to understand the processes that produce these rapid changes. The height will also help them learn how much energy is required to light up auroras.

"I was wowed when I saw these images and the curtain," said Tamas Gombosi of the University of Michigan in Ann Arbor, who chairs Cassini's and plasma science working group. "Put this together with the other data Cassini has collected on the auroras so far, and you really get a new science."

This video is not supported by your browser at this time.
Credit: NASA/JPL/Space Science Institute

Ultraviolet and infrared instruments on have captured images of and data from Saturn's auroras before, but in these latest images, Cassini's narrow-angle camera was able to capture the northern lights in the visible part of the light spectrum, in higher resolution. The movie was assembled from nearly 500 still pictures spanning 81 hours between Oct. 5 and Oct. 8, 2009. Each picture had an exposure time of two or three minutes. The camera shot pictures from the night side of Saturn.

The images were originally obtained in black and white, and the imaging team highlighted the auroras in false-color orange. The oxygen and nitrogen in Earth's contribute to the colorful flashes of green, red and even purple in our auroras. But scientists are still working to determine the true color of the auroras at , whose lacks those chemicals.

Provided by JPL/NASA (news : web)

Explore further: Red moon at night; stargazer's delight

add to favorites email to friend print save as pdf

Related Stories

Cassini Finds Mysterious New Aurora on Saturn

Nov 12, 2008

(PhysOrg.com) -- Saturn has its own unique brand of aurora that lights up the polar cap, unlike any other planetary aurora known in our solar system. This odd aurora revealed itself to one of the infrared ...

Study finds Earth's auroras are not mirror images

Apr 06, 2005

Thanks to observations from the ground and satellites in space, scientists know that the North and South Poles light up at night with Auroras because a "solar wind" of electrified gas continually flows outward ...

Saturn’s radio emissions and bright auroras are linked

Feb 17, 2005

Just as the static on an AM radio grows louder with the approach of a summer lightning storm, strong radio emissions accompany bright auroral spots -- similar to Earth’s northern lights -- on the planet Saturn, according ...

Recommended for you

Astronauts to reveal sobering data on asteroid impacts

9 minutes ago

This Earth Day, Tuesday, April 22, three former NASA astronauts will present new evidence that our planet has experienced many more large-scale asteroid impacts over the past decade than previously thought… ...

Rosetta instrument commissioning continues

49 minutes ago

We're now in week four of six dedicated to commissioning Rosetta's science instruments after the long hibernation period, with the majority now having completed at least a first initial switch on.

Astronaut salary

1 hour ago

Talk about a high-flying career! Being a government astronaut means you have the chance to go into space and take part in some neat projects—such as going on spacewalks, moving robotic arms and doing science ...

Red moon at night; stargazer's delight

20 hours ago

Monday night's lunar eclipse proved just as delightful as expected to those able to view it. On the East Coast, cloudy skies may have gotten in the way, but at the National Science Foundation's National Optical ...

Meteorites yield clues to Martian early atmosphere

22 hours ago

(Phys.org) —Geologists who analyzed 40 meteorites that fell to Earth from Mars unlocked secrets of the Martian atmosphere hidden in the chemical signatures of these ancient rocks. Their study, published ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

dhake_telus_net
not rated yet Nov 25, 2009
Awesome!! Cassini is a marvel, and makes it all seem so easy. David H.

More news stories

A sharp eye on Southern binary stars

Unlike our sun, with its retinue of orbiting planets, many stars in the sky orbit around a second star. These binary stars, with orbital periods ranging from days to centuries, have long been the primary ...

Astronaut salary

Talk about a high-flying career! Being a government astronaut means you have the chance to go into space and take part in some neat projects—such as going on spacewalks, moving robotic arms and doing science ...

Rosetta instrument commissioning continues

We're now in week four of six dedicated to commissioning Rosetta's science instruments after the long hibernation period, with the majority now having completed at least a first initial switch on.

Hubble image: A cross-section of the universe

An image of a galaxy cluster taken by the NASA/ESA Hubble Space Telescope gives a remarkable cross-section of the Universe, showing objects at different distances and stages in cosmic history. They range ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...