What are these strange metal spheres that fell from the sky in India?

Last week, multiple metal spheres of unknown origin fell from the skies in villages within India's western state of Gujarat. The metallic balls are reportedly hollow, .45 meters in diameter, and weigh around five to six kilograms. Fortunately, the balls didn't drop on any human's head but a fragment of metal that fell with the spheres did kill a lamb. From The Swaddle:

According to [Indian Space Research Organisation retired scientist B.S. Bhatia], the metal balls may actually be storage tanks used in rockets and satellites for hydrazine — a kind of liquid fuel. After they run out, they're programmed to detach and fall away, he explained, adding that it's "a very common fuel, primarily used to keep satellites in their orbit."

In the meantime, Jonathan McDowell, an astronomer at the Harvard Smithsonian Center for Astrophysics has a theory about the origin of heaven's metallic wrath on Gujarat. According to him, the debris may be traced back to China's "Chang Zheng 3C serial Y86 rocket" that recently re-entered the atmosphere of the Earth. "The third stage from the [rocket], which launched the [a] communications satellite in Sep[tember] 2021, re-entered today sometime around 0900-1200 UTC… appears a fair match for the re-entry over Gujarat at 1115 UTC May 12 from which debris has been found on the ground," he tweeted.

image: Tithi Luadthong/Shutterstock