On Friday, September 15, around 7:55 am EDT, NASA will tune in to watch its 20-year-old, $4 billion-plus Cassini spacecraft crash into Saturn.
And you can join them. Starting at 7 am EDT, NASA will be streaming live shots from inside the Jet Propulsion Laboratory mission control. Scientists will offer commentary on the mission’s incredible history and achievements.
The most dramatic moment to watch for is likely to be when JPL loses its connection with the plummeting spacecraft just before 8 am. That will mean this remarkable spacecraft has been destroyed by the intense forces in Saturn’s atmosphere. (By the time NASA gets the last signal, Cassini will actually be long gone. It takes about an hour and 20 minutes for communications to transmit between Saturn and Earth.)
For the Cassini mission scientists — many of whom have worked on the project since the 1980s — this will be an emotional, bittersweet moment. It will be interesting to watch the engineers’ and scientists’ faces as their beloved spacecraft goes offline.
“It’s been part of my life for so long, this spacecraft, it’s going to be a shock to have this happen,” says Thomas Burk, a JPL engineer who has been with the Cassini mission for decades, anticipating the moment Cassini goes offline. “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.”
Cassini has made discoveries that have changed our understanding of Saturn and the cosmos at large. The spacecraft discovered whole new moons around Saturn, lakes of methane on Titan, and jets of water erupting from Enceladus, and has made extremely detailed observations of the planet’s rings, an environment believed to be similar to the rings of debris that formed the entire solar system.
But NASA’s final precious few moments with Cassini won’t be wasted. Through its very last moments, Cassini will be conducting a scientific investigation. As it descends into Saturn’s atmosphere, several of its instruments will be on, including the mass spectrometer, which can essentially “sniff” the atmosphere and determine the chemical compounds therein.
Further reading: Why NASA is crashing the $4 billion Cassini spacecraft into Saturn
- One reason: to protect Saturn’s moons — including Enceladus and Titan, environments that could potentially harbor life — from contamination via Cassini debris.
- The Verge’s Loren Grush reports that when NASA engineers were considering options for ending the Cassini mission, eyes lit up when the idea for the “grand finale” was mentioned. “You should have seen the eyes of the scientists,” NASA’s Scott Edgington told her. “They were like kids in a candy store.”
- National Geographic has a very beautiful graphic feature charting Cassini’s path through the Saturn system these past 13 years in orbit.
- Be sure to learn about a few of Saturn’s moons, which are awesome. Enceladus, an ice world with an underground ocean, is one of the most likely places to find life in our solar system.