Bill's Sky

     I am trying to take advantage of as many clear nights this year as I can. That doesn't always mean they are the best for observing, but just getting out and trying to learn and see more is very gratifying in itself. 2 May 2026  2 May was a day past the full Moon. I was curious about how bright it actually made the sky so I checked out the Starry Sky kit from the library to use the SQM (Sky Quality Meter). These are made by Unihedron and measure the sky in magnitude/arcsecond. It is an objective measurement as opposed to the subjective Bortle Scale that is widely used by amateur astronomers. The SQM uses the same magnitude scale that is used for stars. Therefore, the higher the number, the less bright the sky background is. The brighter the background sky glow, the lower the number. At 22:15 MDT the Moon was  about 40 degrees above the horizon. Standing in a spot shaded from moonlight by a tree, I got an average reading of  19.17 with the ...

The full Moon is tomorrow, tonights is at 98% full. I haven't bothered to look at it because this full there is low contrast with no shadows. Most features are harder to make out. Common wisdom is that there really isn't much to see like this. However, I had read that sometimes when the surface is this bright you can see hints of the faint mineral colors. Professional Astronomers use filters and processing images to bring out these faint colors.             " Even if the moon really were made of green cheese it probably wouldn’t look this bizarre. Still, this mosaic of 53 images was recorded by the Jupiter-bound Galileo spacecraft as it passed near our own large natural satellite in 1992. The pictures were recorded through three spectral filters and combined in an exaggerated false-color scheme to explore the composition of the lunar surface as changes in mineral content produce subtle color differences in reflected light. Image credit: NASA/JPL "...

  Got set up about 22:15 MDT. IJust did a SkyAlign using three bright stars. First was Arcturus, but I forgot to note the other two. That's something I need to be sure to do from now on. NELM was about 3.5-4. Stars not twinkling very much st zenith, but twinling more as you looked lower. Transparency was about 3/5 and got worse as the night progressed. I initially thought it was possibly moisture in the air, but humidity was only about 34% and dew neve formed on any surfaces. It turned out to be smoke haze. By 08:00 the next morning the smoke in the valley was thick enough to smell and there was a haze over everything. The Moon was about 17% waxing. I wanted to observe it before it went behind the trees to  the west so it was my first target. I started out using the 25mm Plossl eyepiece (81x), and worked north along the terminator from the south edge. After getting a good overall view I went to Mare Crisium. While scanning around it a detail I hadn't noticed before caught my e...

I first went out about 21:15MDT to see what the sky was like since the forecast wasn't too promising.  I thought I saw a possible Aurora to the north and northwest. I got the night vision scope out to see and it turned out to just be skyglow on some thin clouds.  It was about an hour after sunset and several hours until moonrise. The sky glows from Hamilton (about 16 miles north) and Darby (1 mile south) were quite a bit larger than usual. There were also high thin clouds to the west but Jupiter was still clear of them. The stars weren't twinkling very much at zenith, but transparency wasn't very good. NELM was about 4. Haze made larger than usual halos around lights on the truss company just under half a mile away and on lights in town a mile away. I would rate the transparency about 3/5. I decided to try it anyway. A quick note about those lights. They are south of me and the walls of my observatory are 5ft tall so I can get as close to the southern horizon as practical f...

I have been disappointed with views of the planets in my C8 SCT ( Celestron 8" Schmidt Cassegrain Telescope). I am not seeing the level of detail it should provide. On Jupiter I can regularly see the North and South Equatorial Bands, but no detail in them and only occasional hints of other bands. There are several potential reasons for this, especially sky conditions. I live in a mountain valley between two significant mountain ranges. The highest range, the Bitterroots,  are just west of me and very rugged. This means there can be significant disturbances to the airflow above me affecting seeing . To test this out I wanted to set up my old 4.5" Newtonian Reflector on a German Equatorial Mount (GEM, or just "equatorial", for short). I had not used it in several years. This telescope is old enough that it uses 0.965" eyepieces. Over 20 years ago I remember using it in alt-az mode and seeing the Great Red Spot and more detail than I am getting now with the SCT. T...

Top image is sketch of M65 and 66 through 32mm Plossl. Bottom image is sketch of Jupiter through 25mm Plossl with 2x Barlow      The sky tonight is very bright. The Moon is about 75% illuminated. Transparency isn't real great, there is a layer of haze/light smoke over the valley. The layer is visible as you look at the horizon. NELM is about 3.5. I can barely make out Pherkad and 3 of the stars in the handle, including Polaris. Despite this I wanted to observe some of the Messier Objects in "Turn Left At Orion" while they are visible. This is the time of year when most of them are visible and I hoped to see quite a few before they are gone for the year. This is also the time of yer that a lot of amateur astronomers engage in a Messier Marathon . The goal is to observe all 110 objects in a single night. It's not for me, but a lot of people enjoy the challenge.  I had remounted the OTA on the pier before dark to get ready. My first targets were picked because they wou...