A particularly saucer-y lenticular cloud, over Dublin in June. (Photo: Omnisource5/WikiCommons CC BY-SA 4.0)
This past weekend, eerie shadows passed over Cape Town, South Africa. Those who looked up saw huge puffy saucers hovering overhead, their dark underbellies promising either rain or aliens. In preparation, everyone hauled out their #UFO hashtags, as is customary around the globe.
These particular flying objects actually can be ID'd: they're lenticular clouds. This cloud type, which gets its name from the Latin word for "lens-like," is formed when strong, wet winds cool and condense as they blow over large obstructions, explains National Geographic's Brian Clark Howard. That's why you can often find them downwind of big landscape features, like Cape Town's Table Mountain.
Local legend offers a different explanation, saying that the puffs are from a smoking contest between the devil and a Dutch pirate named Van Hunks. "It is said that Van Hunks won the competition but the Devil challenged him to a re-match," which accounts for the frequent stream of huge puffs, explains a local guidebook.
UFOs and pirates aside, these particular clouds abducted no one. Instead, observers beamed their pictures up to Instagram, a good place to see the invasion's progression.
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