Cloudy UFO Over Mt. Hood

Bad Astronomy
The entire universe in blog form
March 30 2013 8:00 AM

Lenticular by Night

Cloudy nights aren’t always a disaster for astrophotographers.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Take Ben Canales. He takes magnificent night sky photos (like this one in Oregon that totally blew me away), so you’d think he’d always want clear skies.

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But on Mar. 9, 2013, near Mt. Hood in Oregon, he took this unbelievable picture:

Ben Canales pic of Mt Hood and cloud
The scene shortly before Richard Dreyfuss flies away into the night and the John Williams music kicks in.

Image credit: Ben Canales (used by permission)

I know, right? That’s a lenticular cloud, so called because they’re shaped like lenses. They’re fairly common near tall mountains, where moist air flowing around and over the peak condenses downwind of the mountain. The air is always flowing, but the spot where the moisture condenses is stationary, so it looks like the cloud is hovering.

Some lenticulars are huge and dramatic, looking just like UFOs (and because they hover they’ve been reported as such). Others are smaller, and may only be rounded on the upwind side, trailing away downwind. I see that kind all the time here in Boulder, with the ragged tops of the Rockies to the west.

Ben’s shot is incredible. Mt. Hood and the cloud dominate the shot, but if you look at the full-res picture you can see some stars dotting the sky; I could see the constellations of Cassiopeia to the left of the volcano and part of Aquila to the right. He mentioned he took this shot at dawn, so I knew he was west of Mt. Hood facing east, making the stars easier to identify.

Taking great pictures takes a lot of preparation and experience, but sometimes being lucky helps. Even if that luck is bad—and clouds block the star shot you want—you can still make some good of it.