Syfy Insider Exclusive

Create a free profile to get unlimited access to exclusive videos, sweepstakes, and more!

Sign Up For Free to View
SYFY WIRE Bad Astronomy

Red Rock, Black Spider, Blue Moon

By Phil Plait

Your word of the day is lunation.

This is the term given to a single cycle of the phases of the Moon, from new to full and back to new again. A lunation is about 29.5 days (think âmoonthâ if that helps). Each lunation is given a unique numberâthere are various systems, but the most common starts with the cycle that began in January 1923. In that case, as I write this, weâre in Lunation 1121.

This last full Moon was interesting. Some people were calling it a Blue Moon, which made me chuckle: The term has no scientific meaning but has a cultural one of being the second full Moon that occurs in a calendar month. However, that canât be true in this case, since the full Moon was just after midnight on the evening of Aug. 20-21. If it takes nearly 30 days to go through a set of phases, the Blue Moon has to happen on the last couple of days of the month.

Some people say a Blue Moon is the fourth full Moon in a season, but even that is more folklore than anything else. The term really just means something very rare and was later adopted to pertain to the actual phase of the Moon. And it has nothing whatsoever to do with the color of the Moon. So there.

Still, because of the buzz, a lot of folks went out to look at the Moon (I tweeted about it, tooâtwice actually, the second one being a joke). A lot of people sent me pictures of it, and a couple from this current lunation were cool enough that I wanted to share.

The first (shown above) comes from my friend Storm DiCostanzo, aka âand Stormâ, one half of the musical geek duo Paul and Storm. He and his wife happened to be in Australia at the same time I was recently, and we got together to spend an afternoon in Sydney. They told me they were going to Uluru, aka Ayers Rock, and I was jealous; Iâve always wanted to visit. But that jealousy increased hugely when I saw the amazing shot Storm took.

Uluru is a several-hundred-million-year-old sandstone inselberg (island rock) in central Australia. Itâs difficult to get to and is incredibly isolated from cities. The skies there get substantially dark, though the nearly full Moon would bleach out the stars. Still, if it means getting a photo like Stormâs, then maybe thatâs worth it.

The second shot is a bit more whimsical and was sent to me by Steve Marr (arachnophobes, you may want to skip this one):

This is actually whatâs called a high-dynamic range or HDR picture. When you take a picture with your camera, it sees light linearly; that is, something twice as bright looks twice as bright in the picture. Our eyes donât really see that way, though. Itâs complicated, but overall we see logarithmically: Something twice as bright might only appear fractionally brighter to our eye. Thatâs why most pictures overexpose so quickly while our eyes see the same scene just fine.

HDR photography compensates for this a bit. The camera takes three exposuresâone short, one medium, and one longâto be able to see bright, medium, and faint highlights. It then combines them into one shot that more closely mimics what the eye can see.

Thatâs what Marr did for this lunar arachnophilic picture. It also gives the picture a slightly creepier edge to itâlike it really needs it.

We see the Moon almost every day, sometimes at night, sometimes during the day, sometimes full, sometimes new, and with every phase in between. Itâs always changing, always different, and always lovely to behold. If you can, go take a look.

Read more about: