I feel like I’ve become a tiny bit obsessed with Saturn ever since NASA announced that Cassini would be ending her 13-year mission. It seems almost hypocritical of me since I didn’t even know Cassini was even out there in the dark vacuum of space until I wrote this article a few months ago. However, now that I’m paying attention to Cassini, I realize that there are exciting things are happening and I’m thrilled about them!
Take for example Saturn’s moon: Enceladus. At the beginning of April, NASA announced that the moon could potentially host water-based life. Now scientists have announced that they believe Enceladus’ axis has moved 55 degrees. The most likely cause for this comes from “some of Enceladus’ mass being redistributed, making the moon’s rotation unsteady and wobbly,” NASA officials stated in a recent report.
How exactly did this shift in mass occur? In the same report, NASA suggests that the most likely reason was a collision with an asteroid near the moon’s south pole. This hypothesis comes from a study led by Radwan Tejeddine, a Cassini imaging team associate at Cornell University.
During the research process, scientists found long, linear fractures near the south pole that they called “tiger stripes.” Cassini first noticed these tiger stripes back in 2005 when scientists noticed water spewing from them into space, suggesting there was a subsurface ocean.
Tejeddine’s team stated in that report that these geological anomalies are unlikely to have happened on their own; they seem to believe that they could have only been caused by a tremendous impact.
Further evidence for this is that the moon’s northern pole is drastically different from the southern pole in geological activity and texture. The northern region is not nearly as pocked with craters and fissures, pointing to an older surface unchanged by a large impact. Scientists hypothesize that before the collision, the two sides of the moon looked similar to each other.
Whatever the cause, the rotation of the moon would not have likely been stabilized for more than a million years. By the time it eventually stabilized, the north-south axis would have reoriented to pass through different points on the surface, something that researchers call a “true polar wander,” the statement said.
Written by Staff Writer Dusty Langdon
Dusty is a community college student who lives in Peoria, Il. She is a NASA Community College Aerospace Scholar (NCAS), and has always loved space, math, and learning new languages. When not writing for our blog, Dusty spends her time writing stories, reading, watching television, and hanging out with friends.
Photo Credit: NASA/JPL-Caltech/Space Science Institute/Cornell University