The mysteries of our vast universe never cease to amaze and expand our wealth of knowledge. It’s undeniably true that space is filled with unending secrets, ready to be discovered and explored. In the spirit of such noble curiosity, our focus shifts toward Saturn, the sixth planet from the Sun, a gas giant known for its beautiful and distinctive rings. Among the 82 known moons orbiting Saturn, lies a rather small but fascinating one – Enceladus. This tiny celestial body has a unique element that has caught the attention of many space scientists – it hosts a hidden, or more precisely, a ‘secret ocean.’
Enceladus, with a diameter of a mere 500 kilometers, is tenth of Saturn’s moons in terms of size. A glance at it might not reveal its true wonders. However, what lies underneath its surface is what has remarkably reframed our understanding of this moon. Amid the cold, icy surface lies an unexpected reservoir of liquid water. This ‘secret ocean,’ as it is often referred to, is not just a small lake or a pond, but a vast, subsurface salty ocean that covers the entire moon.
This intriguing discovery was made possible by the diligent work of NASA’s Cassini spacecraft. Its decade-long sojourn around Saturn provided extremely valuable data about the planet and its many moons. Upon close observations of Enceladus, the spacecraft detected tiny grains of silica in the moon’s atmosphere. For such grains to exist, they would need hot, mineral-laden water contacting rocky silica. This was the first hint about the possibility of an ocean beneath its surface.
However, the Cassini mission scientists needed more proof. Studying the moon’s geysers, they noticed icy particles differing in composition, temperature, and speed. This suggested that they originated from a liquid reservoir. The ultimate confirmation came when the spacecraft flew through these icy plumes and detected molecular hydrogen. This was significant because the most plausible source of such hydrogen is a hydrothermal reaction between heated water and rocks.
What’s more, there are clear indications that the hidden ocean of Enceladus might even harbor life. The presence of molecular hydrogen indicates the presence of hydrothermal activity. On Earth, such hydrothermal vents in our oceans act as oases of life, supporting unique ecosystems. This principle opens up the intriguing possibility of Enceladus’s secret ocean also hosting life forms, powered by these hydrothermal vents.
Even though Enceladus