Saturn's Icy, Oceanic Moon Enceladus May Have Tipped Away From Its Original Axis
A new study by astronomers from the Cornell University, University of Texas and NASA revealed that Saturn's large, icy, oceanic moon Enceladus may have been tipped away from its original axis.
The study, published in the journal Icarus, showed that an asteroid may have walloped Enceladus. in the past. As a result of the impact, Saturn's icy moon was tipped away from its original axis by about 55 degrees.
"We found a chain of low areas, or basins, that trace a belt across the moon's surface that we believe are the fossil remnants of an earlier, previous equator and poles," explained Radwan Tajeddine, a research associate in Cornell's Department of Astronomy and lead author of the study, in a press release. "Their pattern reflects spatial variations in the icy shell, consistent with a variety of geological features visible in Cassini images."
For the study, the researchers combed through the data provided by NASA's Cassini mission. By carefully examining the geological features of Enceladus, the researchers found possible evidence that the moon underwent a mechanism called "true polar wander" and changed its north-south axis.
"The true polar wander hypothesis seems very plausible when we take a combined look at the patterns of highs and lows across the moon's surface, the physical appearance of surface features and the differences between the current poles," said Tajeddine, who is also an imaging team associate at Cassini.
The current south pole of Enceladus is surprisingly more active than its northern counterpart. Astronomers observed that active jets discharge water vapor through vents from an ocean deep beneath the moon's icy-crust surface. Due to this, astronomers have named the long, geological active fractures as "Tiger Stripes".
The researchers noted that the current south pole of Enceladus was actually much closer to the equator. An asteroid may have strike that area in the past, tipping it away from its original axis. The researchers believe that the moon may have re-establish stability after over a million years.