Saturn's Rings Show Evidence of a Modern-Day Collision

October 11, 2006
Saturn's Rings Show Evidence of a Modern-Day Collision
Saturn's D ring--the innermost of the planet's rings--sports an intriguing structure that appears to be a wavy, or "vertically corrugated," spiral. Image credit: NASA/JPL/Space Science Institute.

Scientists with NASA's Cassini mission have spied a new, continuously changing feature that provides circumstantial evidence that a comet or asteroid recently collided with Saturn's innermost ring, the faint D ring.

Imaging scientists see a structure in the outer part of the D ring that looks like a series of bright ringlets with a regularly spaced interval of about 30 kilometers (19 miles). An observation made by NASA's Hubble Space Telescope in 1995 also saw a periodic structure in the outer D ring, but its interval was then 60 kilometers (37 miles). Unlike many features in the ring system that have not changed over the last few decades, the interval of this pattern has been decreasing over time.

These findings are being presented today at the Division for Planetary Sciences Meeting of the American Astronomical Society held in Pasadena, Calif.

"This structure in the D ring reminds us that Saturn's rings are not eternal, but instead are active, dynamical systems, which can change and evolve," said Dr. Matt Hedman, Cassini imaging team associate at Cornell University, Ithaca, N.Y.

When Cassini researchers viewed the D ring along a line of sight nearly parallel to the ringplane, they observed a pattern of brightness reversals: a part of the ring that appears bright on the far side of the rings appeared dark on the near side of the rings, and vice versa.

This phenomenon would occur if the region contains a sheet of fine material that is vertically corrugated, like a tin roof. In this case, variations in brightness would correspond to changing slopes in the rippled ring material.

Both the changes over time and the "corrugated" structure of this region could be explained by a collision of a comet or meteoroid into the D ring, which then kicked out a cloud of fine particles. This cloud might have inherited some of the tilt of the colliding object's path as it slammed into the rings. An alternate explanation could be that the object struck an already inclined moonlet, shattering it to bits and leaving its debris in an inclined orbit.

In either case, the researchers speculate the aftermath of such a collision would be a ring slightly tilted relative to Saturn's equatorial plane. Over a period of time, as the inclined orbits of the ring particles evolve, this flat sheet of material would become a corrugated spiral that appears to wind up like a spring over time, which is what was observed.

Based on observations between 1995 and 2006, scientists reconstructed a timeline and estimated that the collision occurred in 1984.

Source: NASA

Explore further: NASA's GPM observes Tropical Storm Gaston's development

Related Stories

NASA's GPM observes Tropical Storm Gaston's development

August 24, 2016

The Global Precipitation Measurement mission or GPM core satellite provided scientists with a look at rainfall rates and cloud heights within Tropical Storm Gaston as it continued to intensify in the Atlantic Ocean.

Why working mothers go freelance in corporate world

August 23, 2016

The original "freelancers" were historic knights and mercenaries, selling their fighting skills to whoever paid the right price. Today's freelancers include a growing army of people who decide to leave highly paid and secure ...

A practical synthesis for benzazetidine compounds

August 18, 2016

(Phys.org)—A key chemical component to antibiotics, such as penicillin is the beta-lactam, a four-membered amide ring that is fused to another heterocycle. Researchers in drug design would like to explore compounds using ...

Most distant catch for ESA station

August 19, 2016

An ESA tracking station has acquired signals from the international Cassini spacecraft orbiting Saturn, across more than 1.4 billion km of space.

Detecting hearing loss, vertigo via blood tests

August 18, 2016

There are more than 30 blood tests in clinical practice today to confirm disease. For heart attacks, cardiologists test the blood for cardiac enzymes; for osteoporosis, proteins in the blood can signal thinning bones.

A miniaturized sensor that can measure chemistry on a chip

August 17, 2016

By combining expertise in photonics - manipulating light beams in nanoscale waveguides on a chip – and materials science, Cornell researchers have laid the groundwork for a chemical sensor on a chip that could be used in ...

Recommended for you

Rocky planet found orbiting habitable zone of nearest star

August 24, 2016

An international team of astronomers including Carnegie's Paul Butler has found clear evidence of a planet orbiting Proxima Centauri, the closest star to our Solar System. The new world, designated Proxima b, orbits its cool ...

WISE, Fermi missions reveal a surprising blazar connection

August 24, 2016

Astronomers studying distant galaxies powered by monster black holes have uncovered an unexpected link between two very different wavelengths of the light they emit, the mid-infrared and gamma rays. The discovery, which was ...

China unveils 2020 Mars rover concept: report

August 24, 2016

China has unveiled illustrations of a Mars probe and rover it aims to send to the Red Planet at the end of the decade in a mission that faces "unprecedented" challenges, state media said on Wednesday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.