The Russian Air Force, during a mission to clear the skies of potentially rain-filled clouds, dropped a mixture of silver iodide, liquid nitrogen and cement powder in an attempt to seed the clouds. This form of climate modification is common practice in Russia, when attempting to engineer dry days on public holidays and special events in Moscow. However, during the cloud seeding operation last week, cement dropped from one of the aircraft failed to fragment when falling through the air, falling as a solid mass, crashing through the roof of a Moscow suburban home…



Cloud seeding is a highly controversial method used to modify local climates. Russia and China are two large nations that believe various methods of cloud seeding are effective in deflecting storms and preventing rain clouds from precipitating on events requiring dry weather. Silver iodide, dry ice and various salts are used as artificial particles acting as water droplet nuclei. Dropping these particles can trigger precipitation, but any form of climate modification can be unpredictable, and in some cases, dangerous.

One such unpredictable outcome from last week’s “routine” cloud seeding effort by the Russian Air Force above the skies of Moscow resulted in something bigger than rain hitting the ground. A pack of cement (with rain-making properties I’m guessing) was dropped from one of the 12 seeding planes with a cocktail of silver iodide and liquid nitrogen. The point? To clear the skies above Moscow in preparation for a dry national holiday on June 12th known as Russia Day. The result? The cement mix failed to break apart, creating the desired cloud of dust after it was released. Instead it maintained its shape (and presumably its cement-like hardness) and dropped to the ground like a stone rock.

“A pack of cement used in creating good weather in the capital region failed to pulverize completely at high altitude and fell on the roof of a house, making a hole about 80-100 cm (2.5-3 ft).” – Naro-Fominsk Police when talking with agency RIA-Novosti.

Fortunately no one was hurt, but the Russian homeowner is less than impressed. He has shunned the Air Force’s offer of $2,100 to fix the roof and is suing for “moral suffering” damages instead. The Air Force claims this was a freak accident and unheard of in the 20 years of cloud seeding operations.

Sources: Reuters, Environmental Graffiti