Observing the moon in daylight

Moon in daylight? You have seen it, I have seen it, it is broad daylight and there in the sky is the moon. If you stop and think about it you realize that the moon is up in the daytime just as much as it is at night, we just don’t tend to notice it. In my opinion this is a direct result of the fact that the moon has a much higher contrast at night since it is the only rock we see directly illuminated by the sun.

moon in daylight when imaged

The picture above was taken during the day on March 31st 2012. It is a stack of images run through registack to improve detail and sharpness. Yeah, it might be a little too sharp, but that’s OK with me.

One question I always get asked is if I shot that picture in the daylight, why is the sky black? Remember that the moon is very bright, even the moon in daylight is a light gray rock being lit by the sun. The atmosphere is lit by scattered light. In order to darken the moon so that it is not just a white blur you have to reduce the amount of light hitting your camera sensor. This reduction not only darkens the surface of the moon but the sky around it as well. If you look close you will see that the sky around the moon in the above image is not really completely black although it is very dark.

What the moon in daylight to our eyes

In this picture you can see the blue sky, but the moon is way too bright. This is why when you take an image and want to be able to see the surface details you need to darken the image.

What does this mean if you just want to observe the moon in daylight and not take pictures? Remember that moon filter or polarizing filter you use at night? Yup, use that in the day too. The amount of sunlight bouncing off the moon is the same whether it is also shining on you (daytime) or not (nighttime).

If you don’t have one or you want a really nice one there are a few options. First you can purchase neutral density filters which simply reduce the amount of light by a specific amount. The trick is that these reduce all colors of light equally making your view darker, but still correct. You can get both a Baader Planetarium Neutral Density 2″ ND 3.0and a Baader Planetarium Neutral Density Filter 1.25″ ND 3.0 which covers either 2″ or 1.25″ needs. Note the ND 3.0 specification as there are ND 0.9 and ND 0.6 versions as well. The 3.0 is the darkest of them and if you are going to bother I would get the darkest to start with.

You could also go with a variable polarizer which can provide a similar experience. It works by removing stray light that comes in a different angle and only allowing direct rays of light. These can make for sharper images by reducing glare and stray light but often do not cut light as much as the neutral density filters listed above. They also come in both sizes as well such as the Orion 5562 2-Inch Variable Polarizing Eyepiece Filter and the Orion 5560 1.25-Inch Variable Polarizing Filter.

I enjoy viewing the moon in daylight in winter as it is much warmer. Just remember that the seeing conditions are typically worse in the day than at night. This is minimized in the winter when you have the cold crisp air but the light scattering off of particles in the air still present an inferior image in daylight as compared to night.

moon in daylight over some trees

This still is a great way to do some outreach without having to have a group of kids and their parents tripping all over your equipment in the dark in the library parking lot. It is also a lot of fun to observe while waiting for it to get dark so you can observe or image other targets.

When you are ready to do some exploring you can use Sky & Telescope’s Field Map Of The Moon or the Sky & Telescope’s Mirror-Image Field Map of the Moon. I never go out without one of these in my astrophotography kit. These little laminated maps are fantastic for identifying features without getting so detailed as to be overwhelming.

Where do you look? Before the full moon, look in the afternoon. After the full moon, look in the morning. Regardless go outside and look up into the sky!

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Carl Sagan’s Birthday!

One of my childhood hero’s, Carl Sagan was instrumental in getting me and keeping me interested in science and astronomy in particular. I still remember my father and I watching the TV show Cosmos in the late 1970s. It, like any TV program back in those days, was a big family event which sometimes included popcorn or actual TV Dinners on a TV tray (this did not happen very often). Carl Sagan On November 9th, 1934 in Brooklyn, New York, astronomer, astrophysicist and cosmologist Carl Edward Sagan was born to Russian immigrant Samuel Sagan and New York housewife Rachel Molly Gruber. Sagan’s interest in science was ignited at the 1939 New York World’s Fair at the age of four. That fire was continued with his exploration of the public library at the age of five. He was looking for a book about stars. He also took trips to the American Museum of Natural History with his friends at the age of six or seven, again looking for books. His education included a bachelor’s degree in 1954, bachelor’s degree in physics in 1955, Master of Science in physics in 1956, and a PhD in both astronomy and astrophysics in 1960. His popularization of science kicked into high gear with the writing of Cosmos. The book was made into a very popular television documentary named Cosmos: A Personal Journey.

Cosmos The show consisted of thirteen episodes and originally aired in 1980. Cosmos has won an Emmy, a Peabody Award, and been seen in more than sixty countries by over half a billion people. This was so popular that it has been rereleased multiple times worldwide with the latest being the digitally restored and remastered 2009 five-disc DVD set in the UK. His show even sparked a spinoff Cosmos: A Spacetime Odyssey [Blu-ray] hosted by Neil deGrasse Tyson who was an acquaintance of his. Sagan’s widow, Ann Druyan who was a coproducer of the original series is an executive producer on the new series.

He wrote several other science related books including A Pale Blue Dot in 1994 as a sequel to Cosmos. His book The Dragons of Eden: Speculations on the Evolution of Human Intelligence even won a Pulitzer Prize. Sagan was also a science fiction author writing such books as Contact, which was made into the movie Contact [Blu-ray] or Contact (DVD) starring Jodie Foster and Matthew McConaughey. This movie won the 1998 Hugo Award for best dramatic presentation. 

Carl Sagan was the designer of the gold plaques containing the universal message from Earth on two Pioneer spacecraft as well as the gold record on the Voyager spacecraft. Many of his theories and ideas have been proven over the years including the surface conditions of Saturn’s moons Titan and Europa and his ideas on global warming.

One of Sagan’s greatest passions was the search for extraterrestrial life. He served on the SETI Institute Board of Trustees. He was one of the founders of The Planetary Society with Bruce Murray, and Louis Friedman in 1980. The society promotes and participates in astronomy and planetary sciences. It is quite possible that no other person in the history of astronomy has been as successful at popularizing astronomy and science in general as Sagan. Carl Sagan passed away on December 20th, 1996 at the age of 62.

carl sagan Happy birthday Carl Sagan, we miss you!

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Dark site etiquette

Dark site etiquette is an important part of astronomy to ensure that everyone enjoys their evening under the stars.

Dark site etiquette

When you are going out to an astronomy club dark site there are some guidelines you should follow to make it an enjoyable experience for everyone. Some of them probably seem like commons sense, and they are, to someone who understands what is going on. Unfortunately a lot of newcomers have no idea and this can cause friction. Help avoid the friction and stares by following a few simple astronomy etiquette guidelines.

Dark Site Etiquette Guidelines

  1. If you park anywhere near where people are observing make sure you arrive before dark and park your vehicle so that the headlights are pointed away from the observing field. This makes sure that when you leave before the serious observers or astrophotographers (and you will leave before them unless the sun has already risen) your headlights will do as little damage as possible.
  2. Get everything out of your vehicle as soon as you arrive. Stack it next to the vehicle if needed but whatever you do avoid opening the doors and causing the lights to come on repeatedly after dark. It is amazing how bright your interior lights are once everyone’s eyes have adapted to the dark. Many astronomers and astrophotographers go one step further with this dark site etiquette by removing or disabling their interior vehicle lights completely.
  3. Speaking of amazingly bright lights, do not use that super bright LED flashlight or the light on your phone to shine on the walkway so you can see where you are walking. Wait by your car until your eyes adjust to the darkness or bring a dim red astronomy light (available on Amazon or telescopes.com) to light your way. Even if your light is red, never shine it at anyone’s eyes or towards their equipment unless you ask first. Astrophotography is about photographing dim lights in the night sky, many of them red, so your red flashlight will ruin an hour long exposure and tend not not make you any friends. If you want a red flashlight used one specifically for astronomy as they are not stupid bright, one such as the Celestron 93588 Astro Night Vision Flashlight is an excellent choice and very affordable. Getting a dedicated red light for this will show everyone you really care about dark site etiquette.
  4. Never touch someone’s telescope without their express permission. They could be imaging and you are fumbling for an eyepiece to look through, destroying their image they have been exposing for the past hour. Or maybe they are in the process of aligning their telescope and your touching could move it off center messing up the computer’s calculations. Or they could be one of “those” people and they could get pretty hostile that you got handsy with their $1200 eyepiece on their $10,000 telescope (why did you bring it out here then goofus?).
  5. Watch where you step. Remember that many of these telescopes run off power cords, and those power cords run across the ground to outlets. Also watch for the legs of tripods. Tripping over either one can completely destroy an astrophotographer’s entire evening and cause a visual observer to waste thirty minutes or more setting everything back up.
  6. Use the restroom before you come out, some dark sites have no facilities. The bushes may be fine for you but you will be in mixed company and quite possibly have other people’s children running around.
  7. Laser pointers should only be used by experienced astronomers who frequent this dark site. Not only is it dangerous to point a pointer towards a person, it is more than bright enough to ruin someones image should the beam enter the area where they are shooting. In addition, it is not only bad astronomy behavior, but it is also a federal crime in the US and many other countries to point at an aircraft. Do you know where the local flight patterns are around this dark site? I know exactly where they are around mine because I constantly see planes there.
  8. If you borrow something, take it back immediately when you are finished. This is not only respectful but makes sure that the item is available should someone else want to borrow it.
  9. Lastly, if you take your children, please make sure they understand the expected astronomy behavior and keep a close eye on them. While most astronomy events welcome children and indeed are geared towards them in many cases, everyone wants both the child and the very expensive telescopes to survive the night undamaged.

When in doubt about astronomy behavior, ask around. Most astronomy gatherings have more experienced people who will be happy to lead you around and show you the appropriate dark site etiquette. Don’t let these guidelines scare you, we all make mistakes. As long as they see you are making an effort you will probably be excused for any little faux pas you may inadvertently commit.

I hope you enjoyed my article on dark site etiquette!

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Getting Started: Visual Astronomy released

Getting Started: Visual Astronomy is quite a departure for me as most of you know I am primarily an astrophotographer and spend comparably very little time visually observing. When you are imaging for up to ten hours at a stretch however that still leaves a lot of time for visual observing, so compared to many others around me I do a lot of visual observing. It is all relative. There are a lot of fantastic books on general astronomy and observational astronomy. The one thing that I could never find however is a book that got right to the point on how to visually observe that was easily portable. This led me to do the research and write my own.

Getting Started: Visual Astronomy Getting Started: Visual Astronomy is a standard sized book just like my others that gets right to the heart of the matter. It is designed to get you up and observing quickly. It answers all the basic questions and some of the more advanced ones as well making sure you know how to use the equipment you have, and what equipment you may be interested in purchasing. From naked eye observations, through binoculars and all the way to the different types of large telescopes, you will find all the information you need to get out under the stars and begin your journey. It even includes a few biographies of important people such as the father of modern observational astronomy, Galileo Galilei, so that you get a feel for the history of observational astronomy.

You can get more information, read the table of contents and introduction and more at the book’s home page here:


Look for Getting Started: Visual Astronomy in both print and Kindle editions from Amazon. The first person to review the book on Amazon had this to say: “This book will help you get started in Astronomy and answers every question you have plus plenty more you didn’t know you had. From buying your first telescope to how to read star maps this book offers a step by step guide on everything. Written in a well structured format that makes the information easy to digest. Well worth the sticker price for the amount of information contained. I highly recommend.”

I hope you enjoy Getting Started: Visual Astronomy!

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Zhumell Z8 Dobsonian Review, not all dobs are equal

After purchasing my new Zhumell Z8 Dobsonian I thought I would share some information on it.

In doing research for my upcoming book “Getting Started: Budget Astrophotography” I was in need of an 8″ Dobsonian telescope. Lots of people have this type of telescope so it is absolutely one that needed to be discussed in the book. Like most people, I wanted the best scope for the best deal I could get and I had heard a lot about Zhumell Dobsonian telescopes, that led me to Hayneedle.

If you are curious about the design of the Dobsonian, read more at Wikipedia.

Zhumell Z8 Dobsonian Most people who know me know that I typically have a brand preference that I stick with. They also know that I will only stick with that brand if the price, performance and quality are close to the competition. This meant that I wound up comparing the Orion XT8 vs Zhumell Z8. In this case they weren’t really close so I went with the Zhumell Z8 Dobsonian telescope which is the house brand for Hayneedle. To start with the price between the Zhumell and its competition is very close, not really enough to worry about. The Zhumell Z8 Dobsonian comes with both a 9mm 1.25″ eyepiece and a 30mm 2″ eyepiece whereas most competitors including the Orion only ship a 25mm 1.25″ eyepiece or something close. In addition they ship a screw on moon filter and laser collimator, the Orion ships with a collimation cap and cheap reflex finder.

Zhumell accessories While I prefer a red dot finder the 8x50mm right angle finderscope on the Zhumell Z8 Dobsonian is a very nice finder and typically considered an upgrade to a simple red dot. Another huge win for the Zhumell is the dual speed crayford focuser that is just as smooth as silk.

Zhumell focuser Finally, my favorite feature is that the Zhumell Z8 Dobsonian has adjustable pivot points so you can balance the scope (Orion has nothing like this), and then adjustable tensioners on each side (not flimsy little springs or friction tape) so you completely control balance and resistance, nice.

Zhumell pivot points

To make this telescope perfect they should offer a kit that swaps the 8x50mm finderscope with a deluxe red dot, and maybe throw in a 2x barlow which would effectively give you the equivalent of 4.5mm (pretty much unusable), 9mm, 15mm and 30mm eyepieces. Other than that little pickyness, I highly recommend this telescope and consider it the best Dobsonian telescope in this size and price range. If you are in the market for a Dobsonian, this should be on your short list. You can sometimes pick up the Zhumell Z8 Dobsonian used HERE or head on over to telescopes.com to get a new one.

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Huntsville astronomy club’s new website

The Huntsville astronomy club (Huntsville Amateur Astronomy Society) in Huntsville Texas is finally getting ready to move to a new website, complete with image galleries and a forum of our very own. The new address is www.huntsvilleastronomy.org and should feature a lot of great information not just for those in our area, but for anyone interested in astronomy in general. Come on by and take a look!

Huntsville astronomy Once you are finished looking at the new site be sure to email us tell us when you would like to come out to a meeting and meet the gang. We meet at the SHSU observatory which you can find with this Huntsville Texas Map that has the observatory marked. There is a lot of stuff going on in Huntsville astronomy!

The website has a lot of cool information, a forum where you can  communicate with other people, tons of astrophotography from our members, astronomy related weather forecasts, an all sky camera so you can see what the sky looks like at the observatory in real time, links to our member’s websites, and much more.

We meet on a pretty irregular schedule so check the website or email a member for information on the next upcoming meeting. Everyone is welcome, there are no dues, show up, have fun!

Thinking about getting into astronomy or astrophotography and not know where to start? Start by coming to a meeting or contacting the club and we will be more than happy to give you a tour, show you our equipment, and help you decide what you want to do. We can also help make equipment purchase decisions (although you can start a great astronomy hobby with just your eyes or a pair of binoculars!).

Are you a student at SHSU? Be sure to take the SHSU astronomy class! Our Huntsville Astronomy Club president is the instructor so you are sure to have a blast.

Here is a schedule to see when official things are happening at the SHSU astronomy observatory.

Come on out and join us for some astronomy in Huntsville Texas.

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail

Orion Stratus eyepieces review – worth it?

After looking through a lot of eyepieces my go to eyepieces are my Orion Stratus eyepieces. Hopefully this will help you understand why.

Although I am primarily an astrophotographer and so I spend far less time looking through an eyepiece than I do a computer monitor, I still like quality views when I do a little visual.

Like most people, I started with the eyepieces that came with my first telescope. While they did indeed provide a view, once I tried a nice eyepiece I was smitten. There was obviously more contrast making objects easier to pick out, more of the field of view was in nice sharp focus, there was a much wider field of view and last but certainly not least, it was much easier to look through the better eyepieces as they had more eye relief.

Eyepieces generally represent half of the optics in a telescope which should give you a hint as to their importance to the views that you get. The typical problem with any quality product, especially a quality optical product, is they can get very expensive quickly. One can start at the bottom of telescope eyepieces for around $20 each and then move up to the top of the line at over $600 each. I wanted as much quality as I could afford, so where was the best bang for my buck?

Orion Stratus eyepieces Above is my collection of Orion Stratus eyepieces, available from Amazon, including the 24mm, 13mm, 8mm and 5mm. At around $140 each these eyepieces have the specs to put them right in the middle of the pack so I thought they would be a good place to start.

General specifications: Apparent FOV: 68 degrees Elements: 8 Eye relief: 20mm Filter threads: Yes Rubber eyeguards:Yes Material: Aluminum Weight: Approximately 1 pound Barrel size: Both 1.25″ and 2″ without adapter

For those who have only used the eyepieces that came with their scopes these will seem huge and heavy. They average just over 2″ in diameter and roughly a pound. In comparison the typical Plossl eyepiece shipped with starter telescopes is less than 1.5″ in diameter and weighs about a quarter pound.

Size comparison of a plossl and Stratus Right off the bat you realize that the Orion Stratus eyepieces are large eyepieces and are nice to hold on to, and the rubber grips on these do not disappoint. In cold weather with gloves or in the Texas heat with sweat covered hands I had no problem holding on to these things. I have never even come close to dropping one.

Comparing two different eyepieces The most striking thing in switching from a higher powered Plossl to one of these is the eye relief, or distance your eye has to be to get a nice complete image. On the higher powered Plossl eyepieces your eye has to be over the tiny little optical window at just the right distance and any slight movement will cause image problems. These all have large optical windows and plenty of room to move around without distorting your view. Although I do not wear glasses, I can see where people who do would love these.

I primarily use these in my refractors (f6.5 and f7) and find that they provide very nice views. On faster scopes such as an f4.9 Dobsonian you can start to see some coma in the outer 10% on the wider 24mm and perhaps a little on the 13mm.

My favorite eyepiece is the 24mm and while it certainly is no TeleVue 22mm Nagler, it provides excellent widefield views of the sky.

The attention to detail is nice, for example the white painted numbers denoting the focal length on the side of the eyepiece are very large which makes them easier to see out in the dark. The rubber eyecup seems pretty durable while being more than soft enough to be very comfortable. There is a groove machined into the 1.25″ barrel to help make sure it can not come lose from smaller telescopes. The threads for filters are a nice touch and make it convenient for using a moon or polarizing filter.

In a world filled with eyepiece choices how would I rank these in terms of performance for the amount paid? Honestly I wish they were just a tad cheaper and I would give them top honors, although I do believe they are an excellent buy.

Two alternatives are the William Optics SWANs for a little less money and the William Optics UWANs for a little more money, both of which are also excellent eyepieces.

If however you want eyepieces that will not disappoint, fit in both 1.25″ and 2″ focusers without an adapter and especially if you can get them on sale, the Orion Stratus eyepieces are a solid contender for all but the most demanding situations.

I do still have some inexpensive Plossl style eyepieces like the ones that come with some better starter telescopes that I keep around for various uses and comparisons.

Bottom line, when I want to view something in my inexpensive 90mm refractor, my much more expensive 110mm APO refractor, or the University’s very expensive 16″ SCT, I reach for one of the Orion Stratus eyepieces, get yours from Amazon.

Share this post! Facebooktwitterredditpinterestlinkedintumblrmail