...the who's who,
and the what's what 
of the space industry

Space Careers

news Space News

Search News Archive

Title

Article text

Keyword

  • Home
  • News
  • SwRI researcher shows how elliptical craters could shed light on age of Saturn's moons

SwRI researcher shows how elliptical craters could shed light on age of Saturn's moons

Written by  Wednesday, 22 June 2022 10:56
Write a comment
San Antonio TX (SPX) Jun 22, 2022
A new SwRI study describes how unique populations of craters on two of Saturn's moons could help indicate the satellites' age and the conditions of their formation. Using data from NASA's Cassini mission, SwRI postdoctoral researcher Dr. Sierra Ferguson surveyed elliptical craters on Saturn's moons Tethys and Dione for this study, which was co-authored by SwRI Principal Scientist Dr. Alyssa Rhod

A new SwRI study describes how unique populations of craters on two of Saturn's moons could help indicate the satellites' age and the conditions of their formation. Using data from NASA's Cassini mission, SwRI postdoctoral researcher Dr. Sierra Ferguson surveyed elliptical craters on Saturn's moons Tethys and Dione for this study, which was co-authored by SwRI Principal Scientist Dr. Alyssa Rhoden, Lead Scientist Dr. Michelle Kirchoff and Lead Analyst Dr. Julien Salmon.

"Our work aims to answer the broader question of how old these moons are. To get at this question, my colleagues and I mapped elliptical craters on the surfaces of these moons to determine their size, direction and location on the moon," Ferguson said.

Circular craters are very common and can be formed from a wide range of impact conditions. However, elliptical craters are rarer and form from slow and shallow impacts, which make them especially useful in determining an object's age because shape and orientation also indicate their impactor's trajectory.

"By measuring the direction these craters point, we can get an idea of what the impactors that made these craters looked like in a dynamical sense and from which direction they might have hit the surface," she said.

At first, Ferguson was not expecting to find a pattern among the directions of the elliptical craters, but she eventually noticed a trend along the equator of Dione, one of Saturn's small moons. There, elliptical craters were overwhelmingly oriented in an east/west pattern, while the directions were more random close to the moon's poles.

"We initially interpreted this pattern to be representative of two distinct impactor populations creating these craters," she said. "One group was responsible for creating the elliptical craters at the equator, while another, less concentrated population may be more representative of the regular background population of impactors around Saturn."

Ferguson also mapped elliptical craters on Tethys, Saturn's fifth largest moon, and found that a similar size-frequency distribution of craters is unusual for objects orbiting the Sun, but curiously matches estimates for the impactor population that appears to be present on Neptune's moon, Triton. Because that population is thought to be planetocentric, or drawn in by the ice giant's massive gravity, Ferguson's results point to the importance of considering planetocentric impactors when examining the age of objects in the Saturnian system.

"It was really astonishing to see these patterns," she said.

Ferguson believes the equatorial craters could have formed from independent disks of debris orbiting each moon or potentially a single disk that affected both moons.

"Using Triton as a guide, Tethys could reasonably be billions of years old. This age estimate is dependent on how much material was available for impacting the surface and when it was available" Ferguson said. "To be certain, of course, we will need more data, but this research tells us a lot. It can give us an idea of what the formation conditions of these moons were like. Was this a system that was completely chaotic with materials hitting these satellites every which way, or was there a neat and orderly system?"

Ferguson hopes to eventually be able to compare her data from the Saturnian moons to those of Uranus, another ice giant. While current data is inconclusive, one of the flagship missions recommended by the Planetary Science Decadal Survey, which was published in April, is a mission to Uranus and its moons.

"This is the first step toward a new perspective on the cratering history of these moons and their origin and evolution," Ferguson said.

Research Report:"A unique Saturnian impactor population from elliptical craters"


Related Links
Southwest Research Institute
Explore The Ring World of Saturn and her moons
Jupiter and its Moons
The million outer planets of a star called Sol
News Flash at Mercury

Tweet

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only



SATURN DAILY
Scientists model landscape formation on Titan, revealing an Earth-like alien world
Stanford CA (SPX) Apr 26, 2022
Saturn's moon Titan looks very much like Earth from space, with rivers, lakes, and seas filled by rain tumbling through a thick atmosphere. While these landscapes may look familiar, they are composed of materials that are undoubtedly different - liquid methane streams streak Titan's icy surface and nitrogen winds build hydrocarbon sand dunes. The presence of these materials - whose mechanical properties are vastly different from those of silicate-based substances that make up other known sedimenta ... read more


Read more from original source...

You must login to post a comment.
Loading comment... The comment will be refreshed after 00:00.

Be the first to comment.

Interested in Space?

Hit the buttons below to follow us...