https://www.space.com/40168-china-space-station-tiangong-1-crash-tracking.html
But the precision of the times given by China in particular raises an intriguing possibility, McDowell added: "I was very surprised that the Chinese knew when it came down. That's very interesting. What I think this means … is that the first Chinese missile-warning satellite is actually operational now," he said. "They launched it a year or so ago, and it's a big infrared satellite in geostationary orbit, and I'm betting that that's how they knew it came down."