What we’ve been up to: Light Pollution, Solar Eclipse, Lunar Eclipse
If you follow me on Twitter or Facebook, you’ll know that Urban Astronomer has been doing a fair bit of astronomy outreach over recent months. In July, I gave a presentation on Light Pollution for the Rhenosterspruit Conservancy, and in September I filmed the partial solar eclipse, and streamed it live for Slooh.com. And without even realising it, we became a major source of news on a surprising superstition regarding the recent Lunar Eclipse!
Light Pollution Talk
On 19 July, I arrived at The Sheds in Laezonia, a rural area north of Johannesburg (and only about 20 minutes drive from the Urban Astronomer Informal Observatory!). The plan was to give an exciting lecture on Light Pollution to a thronging crowd of budding environmentalists and astronomers, and I’d made a special effort to get my own pictures of bad lighting from the local surrounds. I’d given a similar talk at the same location a year before, and had asked the organisers to please arrange matters so that the Sun wouldn’t illuminate the projector screen. So when I arrived, I was led to a tiny store room, normally used to store hay and animal feed, which would serve as our lecture hall. I was concerned that we wouldn’t be able to fit many people in, but at least it was dark.
While the crowd arrived, I set up the telescope in preparation for the post-lecture stargazing. There were several children present, so I aimed for some distant trees on the horizon and let them have a look. Nobody was particularly impressed, but then they’ve all seen trees before! Worryingly, I noticed many thick plumes of smoke rising up all over the landscape. Fires had broken out, and a fresh breeze was fanning them, and blowing hot sparks to start new blazes, which was when I realised that we were probably going to have another small turn out – most of the people who’d responded to the invitations were hard at work fighting the flames. The thrill of rural life!
We waited a while until, as the Sun approached the horizon, we decided to begin. The talk covered the usual material, although the kids in the audience relaxed me a bit, so that I could drop in a few movie references and speak in a generally lighter, more enthusiastic tone, which is a good thing. Afterwards, I got into a few interesting conversations about the topic with various audience members, until darkness settled, and then we began the sky tour.
Being a little better prepared, and experiencing better conditions than last time, I was able to give a proper tour and got to enjoy some of the best reactions I’ve ever had to views of Saturn, M7, The Moon, Venus and more, from the kids. I want more kids at my talks in future!
Partial Solar Eclipse
Two hours before sunrise, on 13 September 2015, I crawled out of bed, made myself a strong cup of tea, and began setting up my telescope in the front yard. I’ve seen eclipses before, and I absolutely detest getting out of bed, so I was going to simply skip it, but I’d made a commitment to the good people at slooh.com to provide a streaming video feed. They had a show on, with professional commentary to allow anybody in the world to watch the eclipse, but had to deal with the slight problem that it could only be seen from South Africa and Antarctica. I provided the telescope, the camera, and the time, while they provided the software and produced the show.
It was a very seat-of-the-pants affair. I did not own a solar filter, and couldn’t afford to pick one up from my local telescope shop, so a few days before, I had gone shopping: From the stationers, I bought black cardboard, tape, and elastic bands, and from the pharmacist I bought one of those emergency “Space blankets”. The cardboard was cut and shaped into a cap which would cover the corrector plate of my telescope, with only a small 5cm hole to let the light through. This was to stop down the aperture and reduce the amount of heat that needed to be dealt with. The blanket is simply a large sheet of mylar film, similar to that used in eclipse viewing glasses. It’s made from a very thin layer of aluminium, sandwiched between two films of PET. It’s light, crinkly, and lets through a small percent of the heat and light of the Sun. I cut out squares big enough to cover the aperture hole, and taped them on one by one until there were about 4 layers. I then added a fifth full-aperture layer to the inside of the cardboard, as a safety measure in case it tore. Then use tape and elastic bands to fit the whole arrangement over the end of the telescope and there we have it!
I should mention, as a matter of safety, that I would NEVER look through the telescope with that jury-rigged contraption in place. I don’t know exactly what wavelengths are transmitted by that grade of mylar (and I know for a fact that it’s NOT optical grade stuff), so for all I know I might peer into the eyepiece and unknowingly burn my eyes with unfiltered ultraviolet or infrared light. One of these things will cause cataracts; the other can cause instant blindness. It’s too dangerous to take a chance. Camera sensors, on the other hand, are quite a bit tougher than our soggy retinas, and while there’s a small chance of damage, you can always simply replace a camera. With that said, the whole rig operated beautifully, and I was ready to record about half an hour before the show began.
Best moment of the day: managing to catch the already eclipsed Sun as it rose above a local hill. I shared this image on twitter and it got LOTS of retweets! Worst moment: having the battery die on my camera, just as the producers were expecting the moment of peak coverage. I first noticed that the feed had died, and was trying to troubleshoot the camera connection when the message came through: “We lost you…”.
I restarted the camera, and the picture sprang back to life, for about 20 seconds before dying again. And then I realised my mistake. I never realised that a DSLR camera in video mode draws a LOT more power than one taking a series of stills, even the with long exposures that I’m used to from deep sky astrophotography. So the battery only lasted about an hour, where I had expected at least six. Cue frantic apologies, and loading the battery into its charger. A quick conference with the producer later, we agreed to let the battery charge until about ten minutes before the end of the eclipse, then fire the camera back up to catch the point of final contact. Which we did. But because the show was scheduled to continue for at least a half hour past the end of the eclipse, and I knew the battery would never last that long with such a short recharge, I improvised: Seconds after the Moon had cleared the Sun’s disk, I snapped a still image, and then switched the feed from live video to a static view of the still. It was a little dishonest, sure, since the entire broadcast was predicated on the idea of “Live eclipse feed, from South Africa!”, but the battery died again about three minutes later, so at least I saved them having to drop visuals a second time.
But despite the disruption in their show, all was clearly forgiven, since they let me keep the software and gave me a complementary membership at slooh.com, as compensation for my time AND as an incentive to do more broadcasts with them! So keep an eye out, as I’ll definitely be working with them again.
Lunar Eclipse
Remember what I said about planning to skip the solar eclipse? Well the Lunar Eclipse of 30 September was at an even more ridiculous time: Starting shortly after local midnight, ending shortly before sunrise. On a Monday morning. No ways. Although I did actually catch a glimpse when the baby woke me for a change, and I looked out the window to catch a spectacularly dark orange Moon. So I’m grateful to her for giving me that view!
And yet I managed to have a much more significant role than just that. See, about a year ago I wrote an article about Blood Moons, and whether they posed any risk to pregnant women. Everybody I’ve ever shown this article to has laughed at it, laughed at the fools who would believe such a thing, or even laughed at me for writing about it. Yet it rapidly rose in popularity to become the most widely read thing I’ve ever written. I’d say that one article has had more readers than everything else I’ve written in my life combined. A lot of people believe that lunar eclipses have negative effects on unborn children, and they have (what seems to them to be) solid reasons for thinking so. So in the week or so leading up to the eclipse, I noticed traffic starting to rise. In fact, it more than tripled from day to day, until it hit a peak about twelve hours after the eclipse. (Perhaps a lot of pregnant women saw the eclipse by mistake, and wanted to check what damage they had done? Who knows!)
I’m incredibly proud of this. Much of what I do in astronomy outreach is, if I’m honest, driven by ego. It’s nice to be admired and appreciated as the guy who knows things. It’s fun to show people stuff that you yourself take for granted and watch their faces light up. But beneath all that, I believe that this astronomy stuff is important to know, because of its historical role as one of the foundations of modern science, and because of its ability to get modern adults and children interested in science, and to get them to care a little more about the world beyond their immediate borders. And when something I wrote as my own little contribution to the Fight Against Ignorance explodes in popularity like that, well, I can’t help but feel that I’ve made the world a slightly better place. And that is a very satisfying feeling.