DESCRIPTION:
It was just before midnight on Wednesday when a pair of explosions lit up the Chinese port city of Tianjin. No one yet knows what caused the blasts. What is known is they occurred in a shipping container facility, exploded with a force equivalent to two dozen tons of TNT, and claimed at least 50 lives. More evidence is rolling in—some of it from a trio of Asian 1 satellites, which picked up thermal signatures from the twin explosions.

The image here shows the three satellite captures stacked on top of each other. The explosion is shown by the black and grey pixels that appear in the middle of each image. The top is from the Himawari-8, a Japanese orbiter that just came on line in early July and has the best weather sensors in orbit. The other two are older models from Japan (middle panel) and South Korea (lower panel).

Although a tragic case study, it’s impossible not to notice how much more sophisticated Himawari-8 is than its aging peers. Not only is its imagery is far less pixelated, but its capture rate is one image every ten minutes, compared to thirty and fifteen minute respective rates of the satellite imagery shown below it. Even ten minutes is the lower limit of new satellite’s capability. If it had been programmed to focus on Tianjin in advance, it could have returned imagery at thirty second intervals. The frame rate and pixel resolution are such that you can clearly see the smoke clouds from the blast in Himawari-8’s frame2.

All three captures were taken using filters that capture narrow slices of the infrared band, perfect for capturing things like low cloud cover (like the vertical blue pixels on the right hand side of the images), fog, and fire. While captured by Japanese and Korean satellites, the data was turned into imagery by the The Cooperative Institute for Mesoscale Meteorological Studies at the University of Madison, Wisconsin.

The Asian satellites aren’t the only pieces of technology that captured the blast. A local seismograph registered the blasts as 2.3 and 2.9 moment magnitude.

Cell phone video from multiple sources captured the explosion as it happened. In those shots, the fireballs appear to reach hundreds of feet into the sky. Chinese media are reporting over 1,000 fire fighters in the area, though efforts have been momentarily suspended because the authorities don’t know what other dangerous materials might be in the container facility. At least 12 of the dead are fire fighters.

1 UPDATE 3:54 PM EST 08/13/15 Originally, this story listed all three satellites as Japanese. The data in the lower panel comes from a satellite operated by South Korea.

2 UPDATE 8:00PM EST 08/13/15 Earlier this sentence said these are shock waves. This sensor is pretty cool, but it can’t sense sound waves. And if it could, it wouldn’t be able to see them with a 10 minute frame rate. These are smoke clouds, moving at the speed of wind.