Researchers locate possible source of "unusual radar signals" in the far reaches of the Solar System

Scientists believe they have found a tip for the "unusual radar signals" found in the far reaches of the solar system.

The icy satellites orbiting Jupiter and Saturn have perplexed scientists because they are so different from both rocky worlds and most ice on Earth. The markedly different radar signals raised questions about their composition.

Objects are also extremely bright, even in areas that would be expected to be dark.

"Six different models have been published in an attempt to explain the radar signatures of the icy moons that orbit Jupiter and Saturn," Jason Hofgartner, a co-author of the new study said.

"The way these objects scatter radar is drastically different than that of the rocky worlds, such as Mars and Earth, as well as smaller bodies such as asteroids and comets."

Scientists now believe that a specific effect, known as the coherent backscatter opposition effect, or CBOE, is likely the reason extraordinary radar signals returning from satellites.

"When you're at opposition, the Sun is positioned directly behind you on the line between you and an object, the surface appears much brighter than it would otherwise," Hofgartner said.

"This is known as the opposition effect. In the case of radar, a transmitter stands in for the Sun and a receiver for your eyes."

On an icy surface, the effect is even more intense. The light is scattered as it bounces off the ice, making it even brighter.

"I think that tells us that the surfaces of these objects and their subsurfaces down to many meters are very tortured," said Dr. Hofgartner.

"They're not very uniform. Icy rocks dominate the landscape, perhaps looking somewhat like the chaotic mess after a landslide. That would explain why the light is bouncing in so many different directions, giving us these unusual polarization signatures."