Scientists in East China are asking the public to keep an eye out for a giant weather balloon that drifted away after it slipped its moorings on Monday.
The high-altitude balloon escaped researchers from the Chinese Academy of Sciences outside a weather research station in Jinan, Shandong Province.
The white, blimp-shaped craft can fly up to four kilometers high before it explodes and returns to Earth.
Based on weather data at the time, the balloon is expected to have fallen east of the city center.
The hydrogen-and-helium filled craft was carrying weather forecasting instruments to detect temperature, pressure, humidity and wind at high altitudes.
Scientists at the academy said they hope not only to recover the instruments, but also the data important to their weather forecasting research.
A 4,000 yuan ($600) reward is being offered for information leading to the balloon's recovery.