| | Image: KCAL CBS 2 |

Californians should keep an eye skyward. It was entertaining enough when an unexpected and unexplained chunk of ice dropped from the heavens and cratered into an Oakland park last week, but another salvo of ice landed last Saturday, raising eyebrows and questions: Is this coincidence or something more sinister?

Scientists can’t seem to decide. The FAA is investigating the incidents and assuming that the ice chunks originated on aircraft. Scientists at the Planetary Geology Laboratory in Madrid find the aircraft explanation convincing but also suggest global warming as a possible cause. Warmer-than-usual air pushes the next layer of the atmosphere to higher—and colder—altitudes. The resulting temperature differential might lead to the formation of the mystery mega-hail—even when skies are clear. El Niño, anyone? —Eric Mika

Link (via the San Francisco Chronicle)
Link (via KCAL CBS 2)