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Strange circles have once again appeared in the frozen surface of Lake Baikal in Siberia, as spotted by astronauts aboard the International Space Station this April. News reports described the ice rings as a puzzling phenomenon.
But experts say they can explain the mystery, and it's not aliens — methane gas rising from the lake floor represents the likely culprit.
Rising methane might be a reason for such a large ice circle. Have they actually detected methane in amounts enough to cause such a formation?
Methane isn't the only reason for ice circles though. Extremely rare cold-weather conditions can also cause them usually because of a slow turning eddy in slow moving river current, as shown below.