Washington: NASA's Cassini spacecraft will dive through Saturn's icy moon Enceladus on Wednesday, October 28, at a distance of just 30 miles (50 kilometres) above the surface.
The flyby will take place at about 1 p.m. EDT (1700 GMT) Wednesday. It will be Cassini's deepest-ever dive through the Enceladus plume, sampling the ocean of the Saturn's moon. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.
According to NASA, the flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.
Since this plume is thought to originate from Enceladus' underground liquid-water ocean, scientists believe that sample analysis onboard Cassini will shed light on moon's potential to host life.
The mission team is also hopeful the flyby will provide insights about how much hydrothermal activity -- that is, chemistry involving rock and hot water -- is occurring within Enceladus.
The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions -- or a combination of both, added NASA.
The answer would make clearer how material is getting to the surface from the ocean below.
Enceladus is an icy moon of Saturn, discovered by Cassini early in its mission.
Cassini launched in 1997 and entered orbit around Saturn in 2004. Since then, it has been studying the huge planet, its rings and its magnetic field.
With the mission set to end in 2017, the probe will make a final visit to Enceladus on December 19 of this year, during which it will measure heat emanating from the ice cracks that etch across the moon’s south pole.