New Delhi: NASA's Cassini has been a busy spacecraft studying the Saturn planet and its many natural satellites since arriving there in 2004.
Cassini has returned thousands of great images and revealed never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.
Some of the tops discoveries made by the spacecraft include seeing active, icy plumes on the Saturn's moon Enceladus; revealing Titan as Earth-like world with rain, rivers, lakes and seas and many more.
However, measuring the exact length of a Saturn day seems to be one of the big challenges for scientists on NASA's Cassini mission.
Over more than a decade in Saturn orbit, Cassini's instruments have wrestled with confusing measurements to determine the planet's precise rotation rate.
According to Michele Dougherty, principal investigator for the magnetometer instrument (MAG) on board Cassini, measuring the length of a Saturn day was like searching for a needle in a haystack. Now she thinks the old cliché falls short.
"It's more like searching for several needles that change color and shape unpredictably," she said.
As Cassini moved closer and closer to the ringed planet, the spacecraft scanned across Saturn and its amazing rings on April 25 to 27, 2016, capturing several sets of images.
Here's a video released by NASA and obtained from the result of Cassini starring at Saturn for nearly 44 hours, or roughly 4 Saturn days.
Video courtesy: NASA Jet Propulsion Laboratory
Scientists hope to resolve the mystery of Saturn's day when Cassini crashes into Saturn for its last mission, revealing intimate details of the planet before being destroyed in 2017.
NASA says for the final phase of Cassini's mission, the spacecraft will perform 20 orbits just outside of Saturn's main rings starting in November 2016, followed by 22 orbits flying through the unexplored space between Saturn's upper atmosphere and its innermost ring starting in April 2017.
Cassini is the fourth space probe to visit Saturn and the first to enter orbit.