You can watch NASA's Cassini make its 'Grand Finale' dive into Saturn's atmosphere later today: Here's how

NASA’s Cassini spacecraft is all set to end its 13-year mission to Saturn at 5.30 pm IST on 15 September. The spacecraft will be taking a **final plunge into Saturn's atmosphere** and burn up. Before taking the final plunge, the imaging system on Cassini is expected to send back invaluable information. [caption id=“attachment_3928159” align=“alignleft” width=“380”] Cassini orbiting Saturn. NASA[/caption] According to NASA, the spacecraft will make detailed maps of Saturn’s gravity and magnetic fields helping reveal how the planet is arranged internally and how fast Saturn is rotating. More insights into the origins of Saturn’s rings are expected to be revealed during the final dive. Also, the imaging system aboard the Cassini is expected to take ultra-close up images of Saturn’s rings and clouds. By the time the images reach Earth, Cassini will already have taken the final plunge and burnt up like a meteor in Saturn’s atmosphere, says NASA. It takes about an hour and 20 mins for radio transmissions from Saturn to reach Earth. NASA says that the key piece of information will come from Cassini’s mass spectrometer, which will analyse Saturn’s atmosphere as the spacecraft plunges through.

How to watch it live NASA has promised to stream the event live along with commentary starting at 7 am EDT (4.30 pm IST) on 15 September on NASA TV and NASA’s website. It will be streaming live shots from inside the Jet Propulsion Laboratory mission control.

You can additionally watch the stream on YouTube or on the NASA Cassini Facebook page as well. Additionally, Ustream will also be showing a clean feed from the cameras at NASA’s Jet Propulsion Laboratory. Why is the mission ending? NASA’s Cassini will not quite hit 20 years of age when it burns up in the atmosphere; 13 of those years were spent in orbit around Saturn. According to NASA, the spacecraft is running low on rocket fuel, which is used for adjusting its course. Once the fuel runs out, the spacecraft will no longer be controllable. This would normally not matter much in the vastness of space, but two of Saturn’s moons — Titan and Enceladus — are thought to have the building blocks of life, if not already contain alien life. If Cassini crashes into any of those moons, there is a chance that the Earth-based microbes that are already on the spacecraft will contaminate the moons. NASA would like to avoid such an eventuality. According to NASA scientist Jeff Cuzzi, “Titan is of interest from the standpoint of exobiology, the formation of life. Now Enceladus also is because of its liquid ocean. The spacecraft was not sterilised. So we have to actually dispose of the spacecraft with prejudice.” “In order to avoid the unlikely possibility of Cassini someday colliding with one of these moons, NASA has chosen to safely dispose of the spacecraft in the atmosphere of Saturn. This will ensure that Cassini cannot contaminate any future studies of habitability and potential life on those moons,” says NASA. The Cassini mission was launched in 1997 as a joint venture between NASA, the European Space Agency and the Italian Space Agency (Agenzia Spaziale Italiana). It has been orbiting Saturn since 2004, studying the planet. Cassini has been instrumental in sending back photos of the planet’s rings, moons and atmosphere which have increased our understanding of these phenomena. Cassini’s time has been more than fruitful. The spacecraft discovered four new moons orbiting Saturn, methane lakes on Titan and what seem to be water jets erupting from the surface of Enceladus. Even as it dies, burning up in Saturn’s atmosphere, Cassini will be beaming back valuable information. Speaking to Vox, JPL engineer Thomas Burk, who has worked with the Cassini mission, said, “It’s bittersweet in that regard. But it’s a really exciting ending. When we stop getting data, that will be the moment of truth.”