A new study published in the journal Science bills Enceladus as "a cosmic graffiti artist, caught in the act."

Last spring NASA's Cassini spacecraft showed what appeared to be geysers streaming out from Enceladus's surface.

One theory suggests that the plumes are created by liquid water below the surface that freezes instantly in the moon's frigid surface climate.

"Enceladus coats itself, snows on itself, and distributes pure water ice particles on its surface," said lead study author Anne Verbiscer, an astronomer at the University of Virginia.



©NASA/Jet Propulsion Laboratory
A colorized image from the Cassini spacecraft shows a giant geyser emitting a fine spray of material from the south pole of Saturn's moon Enceladus. New research suggests that the icy spray from Enceladus's geysers is blasting other, nearby moons with ice particles, making them brighter and more reflective.

The fluffy texture of this icy coating allows Enceladus to reflect more of the sun's light than any other body in the solar system.

And its neighbor moons are nearly as bright, thanks to the sprays of ice they receive from Enceladus, the researchers say.

"The message seems to be, the closer you are to Enceladus the brighter your surface will be, because it has been coated with fine ice particles from the Enceladus plumes," said Andrew Ingersoll, a planetary meteorologist at the California Institute of Technology, who was not an author of the new study.

"Of course, we still haven't figured out why Enceladus is so special."

Signs of Life?

Like many other scientists, Verbiscer believes that the massive geysers also created Saturn's giant E-ring - the planet's fuzzy-looking outermost ring - and sandblasted many of the other moons orbiting within it.

Verbiscer's team measured the reflectivity of Saturn's moons during an unusual astronomical event in which the moons lined up exactly opposite the sun as seen from Earth.

The alignment and its optimal viewing angle won't be repeated until 2049.

Enceladus's geysers have made the moon a hot spot for astronomers looking for signs of life in space.

If the geysers are drawing from pockets of water below the moon's surface, as some theories suggest, those reservoirs could harbor an intriguing variety of primitive life-forms much like those found in Earth's deep-ocean hydrothermal vents.

Amy Simon-Miller, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, cautions that we don't yet understand the nature of the geysers.

But if they do indicate liquid water, their impact on other moons raises intriguing questions about where life could exist in the solar system.

"Comets have long been considered as a possible source of water and other materials for planets," she said.

"The transport of material between moons could provide further clues about the delivery of the raw materials needed for life to the surfaces of otherwise barren worlds."