Category Archives: Astronomy

We interrupt our traipsing through past Worldcon trips to bring you today’s “Blue Supermoon” rising!

You couldn’t possibly have missed all of the hype. But the short (and factual) description is that tonight the Moon was full (happens every 29.5 days, more or less), it was a tiny percentage closer to Earth than average (its orbit is an ellipse, not a circle, so sometimes it’s a bit closer, sometimes it’s a bit farther away, perfectly normal and routine) which means it was a tiny percentage brighter than average, and it was the second full moon in a calendar month (which happens on average every couple of years because our calendar is weird and irregular and lumpy), and tonight all three of those things happened more or less simultaneously. The press had a field day.

First of all, the camera (and hidden image processing software) in the iPhone 13 doesn’t quite know what to do with an bright orange super blue Moon on a dark-ish, dusk-ish background. It does its best.

The good news is that it did better this time on focusing on the Moon instead of the telephone pole and trees. Not great, mind you, but better.

The good camera (Canon Rebel XT DSLR with a 300mm Tamron lens) is lousy in full auto mode being even older and more computationally primitive than the iPhone. But put it in manual mode and shoot a series of pictures with varying exposures and manually focusing, then something in that series is going to get close.

This is a LOT like what it looked like in terms of color and contrast. And yes, just coming up through the turbulent, hot, pea soup atmosphere over downtown Los Angeles and the San Fernando Valley it does look that distorted and misshapen.

As it gets up a bit and we’re not viewing it through quite so much icky atmosphere, the Moon rounds up and starts to get bright. Like really, really bright.

Which confuses the crap out of the camera, which sees all of that black and wants to do a 1/2 or 3/4 second exposure. Knowing (a little bit) better, I overrode it for a 1/250 second exposure. Still too bright! Should have gone for 1/1000 second. Or shorter.

The iPhone never gets over that and constantly overexposes the scene. But it does a decent job of catching the city spread out down below.

Now that it’s way up overhead, even a 1/1000 second exposure would be way, way too long. I don’t think my older (13 years? 15 years?) DSLR will do an exposure short enough to show detail on any full moon, not just a super duper blue Moon. Not without going to some sort of neutral density filter to cut down on the light.

Regolith is reflective as all get out, especially for just vacuum cured grey dust and pulverized rock!

The 98% full moon (the 100% full moon is at 04:38 PDT on July 3rd, about 28 hours from now) was rising over the house tonight while I was out for a brief walkabout.

The iPhone sees that everything’s getting dark in the dusk and exposes the image appropriately, which leaves the Moon horribly over exposed.

But you can manually override the iPhone’s automatic settings and see detail on the Moon! But you won’t see much of the house and flag and trees.

There seems to be a LOT of things in life that are like that, which is a real pain in the ass when you really, REALLY want BOTH!

(And if you see a really nice professional photograph that shows both in this particular instance? I’ll about 99.99999999% guarantee that it’s two pictures photoshopped together.)

No sunrise pictures from Stonehenge for me this year. First of all, there’s that whole “sunrise” and how damn early it is that I’m opposed to. On the other hand, if I were able to make it all the way to Stonhenge for the solstice, I suspect I’d find a way to scrape my sorry ass out of bed early enough to be there.

However, we did have a very pretty conjunction after sunset, starting with the three-day old crescent Moon and the very bright Venus.

A short exposure shows the crescent nicely and Venus is a pinpoint. If I had the telescope out, Venus would show the same crescent as the Moon. (It’s geometry.)

Crank up the exposure and Venus is overexposed but the Moon much more so. There are craters and plains and some details silhouetted at the terminator (the line between sunlight and darkness) but you see the dark portion of the moon dimly illuminated by “earthshine,” light reflected from the Sun off of the bright Earth.

Pull back a little and try to capture some details in the illuminated part of the moon, but I always forget just how stinking bright it is. Even though I had reset for a 1/250 second exposure, it’s still a bit overexposed. I should have gone down at least to 1/1000 second.

Pull back the zoom a little more and try again? Same mistake.

Pull all the way back on the zoom, overexpose for earthshine, and what else shows up? That thing just to the right of the palm trees that looks like a bright red planet? That’s a bright red planet, i.e., Mars.

As always, if you didn’t see this tonight, go look for it tomorrow night or Friday or Saturday. The Moon will be further up and to the left each night (for example, closer to Mars tomorrow) but you’ll still be able to see all of this if you have a clear western sky about an hour to two hours after sunset. Our forecast is for the June gloom to return with the coastal marine layer and fog moving back in, but we’ll see. Maybe the gods will cut us a break.

What does that Magic Eight Ball say? “Outlook not so good!”