The million-pound object floating over your head

That fluffy white cumulus cloud drifting across the sky isn't light at all. It weighs approximately 1.1 million pounds.

This mass comes from trillions of tiny water droplets. Researchers calculate this by measuring the cloud’s volume and multiplying it by the density of its water content. For a typical cloud measuring one kilometer in diameter, the math adds up to over 500 tons of water.

You don't see this weight fall because the water is spread out over a massive space in the form of microscopic droplets. These droplets are so small that it takes a million of them to make a single raindrop.

The cloud stays aloft because the air beneath it is even heavier. The dry air around the cloud is denser than the moist air inside it, creating a buoyant force that keeps the million-pound mass suspended against gravity.

If that same cloud decides to become a storm cloud, like a cumulonimbus, its weight can jump to over 10 billion pounds—the equivalent of 1,000 blue whales hanging in the sky.