NASA shares stunning image of Saturn's icy moon Enceladus
NASA has shared a stunning picture of Enceladus, the sixth-largest moon of Saturn known to harbor oceans beneath its frozen crust. In the color-enhanced image, snapped by the Cassini spacecraft, pale blue fractures—possibly rivers—cut through the surface of the moon and deep craters have also been spotted. The planet is not completely visible since it's obscured by the moon's shadow.
Why does this story matter?
In the hunt for life beyond our own planet, Enceladus's chemistry, vast oceans, and internal heat are some of the reasons that make it a compelling target for investigation. Recently, scientists came up with an idea to probe for life on the icy moon using an orbiting space probe, without actually having to land on the moon.
The average surface temperature of Enceladus is -201 degrees Celsius
Enceladus is the most reflective body in the solar system and this is the reason behind its extremely cold surface temperatures of about minus 201 degrees Celsius. Its icy crust is about 20 to 25 kilometers thick. The moon orbits Saturn at a distance of 238,000km in a tidally locked elliptical pattern, meaning the same face of Enceladus points toward the planet.
Some of the surface fissures could be hydrothermal vents
In the image, it looks like rivers etch the surface of Enceladus. The cracks are believed to originate from relatively warm areas in the crust where ice water and gasses erupt continuously from the oceans below, thereby supplying material to Saturn's E ring. Some of these surface fissures could be hydrothermal vents that extend down to the oceans, according to the space agency.
Why does Enceladus appear white?
Back in 2005, the Cassini probe discovered that these icy water particles and gas gush out from Enceladus's surface at approximately 400 meters per second. While only a small fraction of this material ends up in the E-ring, most of it falls back to the moon's surface like snow, rendering a "bright white" appearance to the icy body.
Enceladus completes an orbit in 32.9 hours
Enceladus orbits Saturn twice every time Dione, a larger moon of Saturn, finishes one orbit. It is because of Dione's gravity that Enceladus has an elliptical-shaped orbit. As a result, Enceladus is sometimes closer and other times farther from Saturn, which gives rise to tidal heating within the moon. Enceladus completes one orbit every 32.9 hours, within the densest part of Saturn's E Ring.
