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Ad Astra

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Everything posted by Ad Astra

  1. Celestial mechanics is often a difficult topic to teach - and to understand! But this activity will help you out a lot. It is also very simple, requiring only a ruler and a clock. The essence of the lab relies upon the fact that almost all adults have about the same reach - and that a ruler held at arm's length shows 1 cm = 1 degree in the sky. While this isn't perfect, it works well enough for most people. The idea here is to measure the Moon's distance from the horizon in degrees several times before moonset; then use the distance traveled and time taken to find the Moon's speed as it tr
  2. Hello Jeriah, I use a lot of Orion equipment (I'm and astronomy instructor), and I have 12 Orion dobsonians in service. The 8" is a super scope and will serve you well for years. These scopes are exactly what my students all learn astronomy on - I recommend them highly. You will find them rugged, easy to set up and use and the views are fantastic - especially for the price you pay. As for the intelliscope, I'm not exactly a fan. They do work, but a computerized mount without the ability to track just isn't my style. I find them a lot more trouble than they are worth - especially as you sa
  3. Here is a scan of the M-13 lab as done by one of my high school students. This lad had never used a telescope or binocular before a few weeks ago. Dan M-13 Sample.doc
  4. This one is for the early birds. The moon has been showing off as it moves across the sky, over the weekend, it will run past Jupiter, then next weekend, it will run past Venus. This is a chance to see the celestial motion of a body in orbit for yourself. The activity is easy enough, just pencil and paper, or go out and have a look. I am asking students to use Orion as a yardstick to approximate the actual travel of the Moon through the skies. Across the top (Betelgeuse to Belatrix) is about 8-degrees, from Beletrix down to Rigel (Orion's right side) is 15 degrees, and across the belt is
  5. Quite a nice shot for a first attempt! Congratulations, Nebula. You get an A on this lab from Dr. Barth! Dan
  6. We had 80 people out in the Astronomy Stadium (I let the football blokes paint silly stripes all over my field and use it during the day... ). All of us were hunting down the elusive M-13 - and doing a bang up job of it, too. Everyone was able to find this object easily enough, and telescope skills are getting better all the time. I was using my GLP to show how to hop from Draco to Hercules to Corona Borealis when one kid asks: 'Where's Ursa Major?' When I pointed out that it was mostly behind the hills at our site, I heard a comment come out of the dark: "Drat! Just when I start to learn
  7. Hi Folks, Hercules is high in the sky and easy to spot - that means it is time for hunting globulars! Globular clusters can contain up to a million stars, all tightly bound together by mutual gravitation. These clusters tend to form a loose shell or halo around most galaxies - thus they are the most distant thing we can see within our own galaxy. Try this one out and let us know how you do. Dan M-13 Cluster in Hercules.doc
  8. Hello friends, I think I must have expressed myself badly again. Let me try to clarify, if I can. My students are studying the Moon just now, and we will discuss theories of the Moon's origin, and evidence for and against those theories. Every theory must account for the evolution of the lunar surface over time (billions of years of time with the rate of impacts decaying much as half-life decay affects a radioactive sample). Because there is no air or water on the lunar surface, you can see evidence of changes in the surface quite clearly even though the actual event occured billions of ye
  9. Hi Big Jim, "One-Page-Easy" is part of the way I write curriculum for my classes. I've found that if I put an introduction, instructions, and a place for a response (data, sketching, etc) - and it still all fits on a single page, then I have made the lab simple enough, short enough, and easy enough that any begining astronomer could happily spend an evening enjoying the exercise, and a high school student could zip through the exercise in under an hour and still do a creditable job. When I post an activity here, I've usually already tried it out with my classes here in California. When I se
  10. My students took this one on tonight with the gibbous moon. Tycho was clear and there was a wonderful view of Gassendi and mare Humorum. We had the C-11 out and the kids followed along on the 150p f/8 dobs and 7x50 bins. I will scan a few of the best and (with permission) post them here. They make a decent mark to shoot at, as none of them have been at astronomy for more than 5 weeks... and they have the added handicap of having me drone on at them for an hour a day! All of the kids found that translating what they were seeing into something comprehensible on the page to be very challengi
  11. Hi Meg, so glad to hear you will be taking it out to the club - let me know how it goes! Dan
  12. Hi Folks, Waxing moon makes a lousy time to go looking for deep sky wonders, so let's concentrate on the lunar surface! For beginners, try the Lunar Sketching Activity. This will familiarize you with basic lunar maria and major features. For more experienced observers, try the Lunar Surface Features Activity. This second activity requires a small telescope and moderate power (60-120x); it challenges you to seek out 10 distinctive lunar features and display them in a series of just 3 sketches. You will have to search carefully to get all 10 in just three sketches! For those of you with cam
  13. With the Moon waxing this week, why not try your hand at really exploring some lunar craters along the terminator? (That's the line that seperates light from dark on the lunar surface.) Lunar craters can show a surprising variety of features and the craters themselves change as they age slowly over billions of years. Download the 'One-Page-Easy' activity and give it a shot. See if you can find, sketch, and then map the location of the features you observe. Bonus points for those who can later positively identify the features they've sketched using a lunar atlas! Give it a go and let us know
  14. My brother-in-law lives in Los Angeles and was good enough to send me these photos of the Space Shuttle Endeavor making its last flight into LAX airport. (Thanks Bill!!! ) The photos are lovely, and I've always found the Shuttle to be a wonderful machine, and I admire the astronaut core very greatly. But I readily admit to very mixed feelings here. My country had no real national service or day of mourning for Neil Armstrong - the first human being to set foot upon another world - and yet we are spending many weeks and loads of hoopla and news coverage of the last tour of a technology we no
  15. Yes, I know it isn't the ideal time of year for Scorpio, but I tend to do things during the academic year and take time off in summer. The other option, of course, is to wait for Scorpio to be an early morning sight in late winter / early spring! Dan
  16. Quite right. If you don't see what you want, then it is time to ask your local dealer. Trust me, these folks live for this stuff. Tell them what you want and give them the challenge, I'm sure they can find (or put together) a package to suit you. This is where you really get your money's worth from the dealer's expertise - and you get just what you want in a telescope package. Dan
  17. I highly recommend the 150-P Dobsonian. I have 12 of them (really!) and all my astronomy students learn on this equipment. The perfect combination of excellent optics, light weight, portability, and optical performance. You would have to go a long way to find something better for the money. You are welcome to PM me if you have further questions. Dan
  18. It seems as though you need something a little more dust proof (and critter proof!) than just a dust sheet. If you are a DIY person, you might try what I did - making your own padded, zip-shut carry bag. I made mine from 'Celestron Orange' canvas (cotton duck cloth) - two layers of canvas with a layer of heat-reflecting curtain liner in-between. Total cost for a tripod bag, scope bag, and accessory bag was less than $25 (most of that was for the zippers!) It isn't what you would call pretty - but it does the job AND keeps the spiders and bugs out. We have both black widows and brown reclu
  19. Hi Folks!, Scorpio is quickly fading into the west, but there is still time to try this double star challenge! The "claw region" of Scorpio is particularly rich in both actual and apparent (visual) double and multiple stars. Even a pair of simple 10x50 bins will reveal many of these targets, while others will challenge even more experienced observers. For the new telescope owner, this activity will offer several enjoyable evenings of activity as you learn to appreciate the wonders of the southern sky. Even experienced observers sometimes miss the beauty of double and multiple star systems
  20. I worked for Scope City for almost 7 years. The company is legit and has been around for at least 30 years. Prices are generally competative and they will often match what someone else advertizes (at least they used to...). They are also very hard-nosed about returns. They used to only offer credit or exchange, not refunds! Mail order may be different, but check with them on this before you order. If the price is good and you know what you want, I wouldn't have any hesitation in recommending them. Dan
  21. I have spoken with some of the folks at Funderstanding.com about doing a 'How to Sketch the Moon' video. If I can get someone to produce it - I will post it here. The actual clock method activity sheet is attached for eveyone - sorry, should have attached that earlier. Like all the activities,it is "One-Page-Easy" and this one has circles pre-marked with 'hour lines' to help you practice sketching. I hope you all enjoy it! Dan Lab Skills - Sketching with the Clock Method.doc
  22. Many of my students shy away from sketching. "I have a camera for that!" and "I'm not an artist!" are often heard in the classroom. Even so, most people find that with a little practice, they can make a creditable sketch of lunar features. Sketching is very pleasing and gives us a record to take away from the eyepiece after a long night of observing. We use a technique that I call the "Clock Method". --> Imagine that the lunar surface is a clock face. --> Start at 12:00. Add in only the general shapes. --> Keep an eye on: a) how large the feature is How far from the center it is
  23. Thrilled to see almost 100 downloads on this one! I took my 4 astronomy classes out last night to look at Lyra. We had over 80 people out on the astronomy pitch (formerly known as the "football stadium"). It was quite lovely and we had a family of coyotes serenading us through most of the eveing with yips and howls. Really added quite the 'Old West' feel to our outing! Dan
  24. I would suggest Lyra. You have the double-double (epsilon-Lyrae), a nice open cluster centered on the star Sulafat (southernmost corner of the parallelogram that makes up Lyra), the Ring nebula (between Sheliak and Sulafat), and nearby is the globular cluster M-56. We were out last night doing the same activity with 80 of my astronomy students! You can find my Lyra activity <HERE>. Dan
  25. As we move into the waxing moon this week, we sometimes find ourselves grumbling that the increasing moonlight interferes with our observation of the deep sky. With the waxing moon, we get to see sunrise spread across the face of the lunar globe over the course of the days, and we can take this opportunity to use the low solar angle to reveal amazing geological features across the lunar surface. We all know that the lunar maria are large impact basins, roughly 3.2 - 4 billion years old, and that after the asteroids punctured the lunar surface, these great basins filled with lava over the mill
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