Cassini made its last closest approach to Titan on September 11 at 12:04 p.m. PDT, at an altitude of 73,974 miles (119,049 kilometers) above the moon's surface, causing the spacecraft to slingshot into its final approach to Saturn - but not before it would send final images from Titan to Earth, eagerly awaited by scientists, including McEwen.
Diagram of Cassini's final week, showing some of the milestones as the spacecraft heads for its plunge into Saturn (times are predicted and subject to change).
You can track the current position of Cassini, relative to Saturn, on NASA's live-updating tracker. It's information that will be studied and analyzed by scientists long after the end of Cassini.
Faced with dwindling propellent supplies, Cassini's engineering team dreamt up an audacious plan to get the most interesting science results possible before safely disposing of the spacecraft. The irony is that, as Earl Maize, the program manager for NASA's flagship mission, put it: "Cassini's own discoveries were its demise". Eight of its 12 science instruments will be operating, allowing the spacecraft to directly sample the composition of the atmosphere and potentially returning insights into the giant planet's formation and evolution. The spectrometer will attempt to investigate what material is from the rings and what material is part of the atmosphere.
On Thursday, the cameras took their final images of Saturn and its system.
"Final approach: the spacecraft is on course to dive into Saturn's atmosphere September 15", Cassini's team said in its twitter on Wednesday. Eastern Time for the spacecraft, but given the time it takes for the signal to reach Earth, we will receive those last bits of data just before 8 a.m. - long after Cassini is "gone". There, at NASA's Jet Propulsion Laboratory, he would attend the final moments of the mission, along with other UA planetary scientists who have participated in the project.
Larry Esposito is a professor of astrophysical and planetary sciences at CU. He's been studying Saturn for nearly 40 years
Mission controllers wouldn't be able to respond to that putative signal in any meaningful way even if they wanted to; Cassini will die almost an hour and a half before such a signal reaches our planet.
Cassini's fate was sealed Monday, when it made its final flyby past Titan, Saturn's largest moon.
Saturn carried out exactly 127 precisely targeted encounters with Titan, either close or more distant ones, and some hundreds of other passes over it as well.
Cassini was sent to Saturn to study its rings, the makeup of its surface and its hemisphere and to study its moons. And NASA didn't want to risk contaminating the moons or any future studies of the moons with Earth particles.
To protect those Enceladus and Titan from contamination with Earth life, Cassini is going to dive down into Saturn's atmosphere before the probe runs out of fuel, which could have left it drifting on a collision course with the planet's moons. And surely that will continue with its final dive, she said. Four years became thirteen, as Cassini continuously exceeded expectations and NASA kept discovering new tasks for the probe. The first space missions that went to Saturn (Pioneer 11 and Voyager) helped scientists begin to understand Saturn's magnetosphere, but the Cassini mission has dramatically enriched our understanding of these.
Within a year of arriving at Saturn, Cassini captured images of plumes of water vapor jetting out from near the moon's south pole. On the flip side, more massive rings would suggest they originated around the same time as Saturn, more than 4 billion years ago.
Kremlin brands Saakashvili's 'illegal border crossing' as political circus
Government officials at the border said 17 police and guards were injured during the confrontation with Saakashvili's supporters. He eventually got off the train and took a bus to Medyka, where he successfully crossed the border.