FAQ
We’ve only got 10 FAQs here, but we’re willing to add more if you have any. If your question is more about how to best use Sky Lights for your specific purposes, you might want to look at my Greetings Reader! page. It’s got some helpful tips for first-time visitors. This FAQ page is more general stuff. If your question is not answered, please contact us and we’ll answer and add it here.
FAQ #0: What exactly happens if I subscribe to Sky Lights?
FAQ #1: Where’s the HOME button that gets me back to your most recent three posts?
FAQ #2: When you show charts of the sky, how much sky am I actually seeing?
FAQ #3: Everything on your sky charts is shifted compared to your compass labels. Am I doing something wrong?
FAQ #4: You use a lot of strange symbols and fonts to label things in your sky charts. What do they all mean?
FAQ #5: If you use equations or special symbols in your blog, I get weird nonsense characters. Why?
FAQ #6: I get the basic idea that larger stars on your sky maps are brighter, but can you quantify that?
FAQ #7: Why do so many of your archived posts use grayscale images instead of color?
FAQ #8: What’s up with those star colors on your sky charts? I can’t see anything close to what you show.
FAQ #9: Can I use Sky Lights in my classroom without your written permission?
FAQ #0: What exactly happens if I subscribe to Sky Lights?
You’ll be escorted through a simple process that sends you an email notice whenever a new Sky Lights is posted (generally every Monday). Sure, you have Sky Lights bookmarked, but a friendly reminder will ensure you never miss out on the latest post. A valid email address is required, and we promise to use it only for Sky Lights update notices. Your privacy is important to us. And you can easily unsubscribe at any time.
FAQ #1: Where’s the HOME button that gets me back to your most recent three posts?
Just click on the Sky Lights logo in the header, and you’ll be teleported right back.
FAQ #2: When you show charts of the sky, how much sky am I actually seeing?
Excellent question since, without a sense of scale, it’s hard to find what you’re looking for. The image below shows a scale of degrees superimposed over the standard sky chart you see in Sky Lights. The use of the human hand to measure degrees is surprisingly accurate. Sure, some people have larger hands, but then, they also tend to have longer arms, so the difference cancels out.
The map itself spans an area of 90° width by 45° height. So if you’re looking straight west, the map shows the sky from SW to NW. From the horizon at the bottom, to the top of the chart, there’s 45° of height — halfway to straight overhead.
FAQ #3: Everything on your sky charts is shifted compared to your compass labels. Am I doing something wrong?
Sky Lights was originally, and still is, written for Arizona skies. Now that Sky Lights is online, with readers from other areas, that creates a problem with some sky charts. Of course, posts about meteorological phenomena are “universal.” There are websites online that can compute your exact sky map wherever you are. See, for example: http://space.jpl.nasa.gov/. But there’s a simple correction you can make to my charts, as long as you know your latitude.
Arizona is at a latitude of 34° north of the Equator. If you’re at latitude 44°, 10° farther north than Arizona, everything in my charts will be shifted 10° south. If you are at latitude 24°, 10° farther south than Arizona, everything in my charts will be shifted 10° north.
Whatever your latitude, posted clock times will be correct for your location. Check the Local & GMT page on this website. Sunset times, however, will vary depending on your latitude. Here’s one of many online sunset/sunrise time calculators: http://www.calendar-updates.com/sun.asp. All you have to do is enter your ZIP code.
FAQ #4: You use a lot of strange symbols and fonts to label things in your sky charts. What do they all mean?
There really aren’t that many to learn. Here’s a quick summary explaining my labeling format.
FAQ #5: If you use equations or special symbols in your blog, I get weird nonsense characters. Why?
If you’re using an older browser, that could happen. Displaying those special symbols requires UTF-8, a way to encode many more characters than what you see on your keyboard. Upgrade to any of the latest browsers, and you should be able to see those special symbols you’ve been missing.
FAQ #6: I get the basic idea that the larger stars on your sky maps are the brighter ones, but can you quantify that?
Certainly! There is indeed a quantitative basis for those sizes. It’s based on a system called magnitude, used by astronomers to designate the brightness of stars. The graphic below explains the details.
Not surprisingly, there’s fewer bright stars and lots of dim stars. It’s interesting to note that, from a reasonably dark location, the average human eye can see around 5100 stars. In the center of a large city, that number can drop to less than 10. Light pollution is the nemesis of astronomy.
FAQ #7: Why do so many of your archived posts use grayscale images instead of color?
Sky Lights started out as a printed newspaper column, and it’s hard to justify the cost of color printing (unless you’re a widely syndicated cartoonist). So I started out with grayscale images, and just accepted the limitations that imposed. Later, when I made the transition to a local newspaper’s website, color became possible. Now, as an online blog, I use color whenever I can, as well as animations where needed. Some of the older posts will be re-released in color if the topic comes up again. But even now, especially for sky charts, sometimes grayscale is all I need.
FAQ #8: What’s up with those star colors on your sky charts? I can’t see anything close to what you show.
In August of 2011, when Sky Lights went online as a blog, I realized I could add a little color to those charts, unlike back in the print era (see preceding FAQ). The graphic below is actually my “worksheet,” from which I drag and drop objects as needed to create my sky charts.
You can see that I use 5 different colors for stars, in addition to 8 sizes indicating brightness. The round dots are the 7 planets visible to the naked eye, displayed in their typical colors.
In fact, the colors of both stars and planets are very subtle and “pastel.” A quick glance skyward by a casual observer would report “all white dots.” But if you know what to look for, you’ll see these colors. The colors used for my sky charts are exaggerated just so you’ll know what to look for. Even then, only the brightest objects will be seen to have color. That’s why most of the dimmer stars are shown as “white,” with a few exceptions. In any case, if you use binoculars or a telescope, all colors will be more apparent.
FAQ #9: Can I use Sky Lights in my classroom without your written permission?
If you’re an educator, you already have my permission. See Legal. Sky Lights is an educational resource that can be freely used by teachers, whether in formal institutions, or in home schooling. Posts may be printed and distributed in a classroom as needed. They may not be altered, reproduced for sale, or converted into other forms for distribution over the internet.
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