Exploring Ariel: Uranus’s Icy Moon

For a long time, the icy moons of Uranus have intrigued scientists, and now it seems that Ariel, the second closest moon to Uranus, may have once harbored a vast ocean beneath its frozen crust. Recent research suggests these oceans might have been deeper than previously thought, opening new horizons for our understanding of these icy moons.

Characteristics of Ariel

Ariel, with a diameter of about 1,159 kilometers, is smaller than many moons orbiting Jupiter and Saturn. Despite its small size, its surface is exceptionally bright and unusually complex, featuring ancient cratered terrains alongside newer, smoother plains. These plains are believed to have formed due to cryovolcanism, a type of volcanic activity that occurs on icy bodies.

According to Alex Patthoff, a scientist involved in the study conducted by the Planetary Science Institute in Arizona, Ariel is unique among icy moons. This uniqueness is attributed to the diverse nature of its surface, providing evidence of complex geological activity.

Studying Ariel’s Internal Structure

Caleb Strom from the University of North Dakota leads a team of researchers investigating Ariel’s past internal structure and orbital eccentricity. The study aims to explain the dramatic features visible on the moon’s surface today. By modeling how Uranus’s gravity influenced Ariel over time, researchers concluded that Ariel’s orbit was once more eccentric than it is now.

Analyses indicate that Ariel’s orbit had an eccentricity of about 0.04, which is 40 times greater than its current eccentricity. This made its orbit more curved compared to Jupiter’s icy moon Europa, known for its cracked and geologically active surface.

The Significance of Subsurface Oceans

Evidence suggests that the cracks and ridges on Ariel’s surface may result from the flexibility of the crust over a liquid layer. This implies that Ariel might have contained a massive ocean covered by a relatively thin ice layer, or a smaller ocean accompanied by stronger tidal stresses.

Subsurface oceans are a major focus in planetary science because they represent potential habitats for life. Liquid water provides the necessary chemical environment for life, and tidal heating or radioactive decay could supply the energy needed to support life, even far from the sun.

Calls for a Uranus Exploration Mission

The study supports increasing calls for a dedicated mission to Uranus. The “Uranus Orbiter and Probe” mission has been nominated as a top priority in the National Academies’ decadal planetary science survey. This mission aims to orbit the planet for at least five years, deploy an atmospheric probe, and explore its rings and moons in detail.

Although Congress has not yet allocated funding, scientists argue that such a mission could answer important questions about Uranus’s extreme tilt, its dense ring system, and its moons that may contain oceans.

Conclusion

Knowledge about Ariel and other icy moons in the Uranus system opens new avenues in our understanding of the universe. Current research provides evidence of subsurface oceans on these moons, enhancing the prospects of finding extraterrestrial life. In the future, advanced exploratory missions may be needed to delve deeper into the mysteries of these icy worlds.