Saturday, October 12, 2024

3D Moon flyover

Full Moon with 3D label
I'm a big 3D fan, especially of stereogram pairs that require no special equipment to see. 

Here is a variety of images featuring different formations on the Moon in 3D. Seeing these from a new perspective adds to our understanding of what we observe in our telescopes. In this case, we are seeing them closer than we ever could from Earth, at differing angles, and in simulated 3D. 

These are stereoscopic pairs using the parallel viewing method. See the instructions for my 3D constellations for details on how to view these. With practice, almost everyone can learn to do it. It's worth the effort!

These images were taken by the Lunar Reconnaissance Orbiter Camera, which has been orbiting the Moon on the LRO since 2009. It has taken some spectacular images of the lunar surface, a few of which are reproduced here in 3D. All images are courtesy NASA/GSFC/Arizona State University. I created the 3D versions using Owl3D and created the location maps with Virtual Moon Atlas. Definitely check out the links to details of the images and browse the other incredible images on the LROC web site. If you have those cardboard anaglyph glasses, they have quite a few images in anaglyph 3D, although the 3D depth tends to be unrealistically exaggerated in some cases.

Many of these features can be observed with small backyard telescopes. The Moon's phase is critical, because features at or near the terminator, the line between night and day, are highlighted with long shadows and can be seen easier. Features near the limb, such as the crater Stevinus, can also be seen better when the Moon's wobble, or libration, presents it a little more favorably towards us. A steady atmosphere and a telescope adjusted to the ambient temperature is also very important. Of course, if a feature is on the far side, we won't be seeing it from Earth. 

Check out this cool NASA simulation to see how much the Moon varies in phase and libration throughout a year. You can also check out how the Moon will look now or at another time for the remainder of this year using NASA's visualization tool.


Unnamed crater between Lowell W and Mare Orientale

This 2.8 mile wide crater sits at the edge of the crater Lowell W and Mare Orientale on the Moon's far side. This was taken when the LRO was at an altitude of 47 miles, facing west. Not visible from Earth. See details about this image.

Stereoscopic pair of Unnamed crater between Lowell W and Mare Orientale









Location of the unnamed crater near Mare Orientale
Mare Orientale on the lunar far side. The arrow just below crater Lowell W points to the unnamed crater in the image above.













Aristarchus central peak

Aristarchus is visible in small telescopes, binoculars, and even with the unaided eye. It is often one of the brightest features visible because it is a young crater, 450 million years old, that hasn't had time for its ejecta material to darken. Here is a closeup crop of the central peak of the crater, taken by LROC from an altitude of 60 miles, facing west. The central peak is about 1,300 feet tall and 9,800 feet wide. The crater is over 2 miles deep. The best time to view Aristarchus is four days after First Quarter or three days after Last Quarter, but try for it around Full Moon and you'll see how bright it appears. See details about this image. 

Stereoscopic pair of Aristarchus central peak






Aristarchus is 25 miles in diameter. Here's another view. See details about this image.

Stereoscopic pair of Aristarchus










Location of Aristarchus
Location of crater Aristarchus in Oceanus Procellarum. South is up.













Messier crater

About 8.7 miles across, Messier is located in Mare Fecunditatis and may have been formed by a low angle impact, causing it's oblong shape. With an apparent size of nearly 7 arcseconds, Messier and its companion crater, Messier A, as well as the two small rays pointing east from Messier A, can be seen in small telescopes. The best time to view Messier is four days after New Moon or three days after Full Moon. See details about this image.

Stereoscopic pair of Messier crater

















Location of Messier crater
Location of Messier crater in Mare Fecunditatis. South is up.















Komarov crater floor (detail)

Located on the far side of the Moon, the floor of 53-mile-wide Komarov crater is covered with deep fractures created when magma rose from the mantle more than 2.6 billion years ago. The largest fractures are about 1,600 feet deep and 8,000 feet wide. Not visible from Earth. See details about this image.


Stereoscopic pair of floor of Komarov crater















Location of Komarov crater

Lunar Orbiter image of Mare Moscoviense with Komarov crater in the left foreground.















Mare Tranquillitatis pit

Pits are relatively small features that may have formed due to the collapse above a lava tube. They were first discovered in 2009 and over 200 have now been identified. The sharp edge of the opening of this pit is about 330 feet across, and the depth is estimated to be about the same. Computer modeling suggests the temperature in the shaded part of the pit may be relatively stable at about 63 degrees F, and there may be a more extensive cave or cave network. The pit is too small to be seen in backyard telescopes. See this article for details.

Stereoscopic pair of Mare Tranquillitatis pit






Location of Mare Tranquillitatis pit
Mare Tranquillitatis pit location. South is up.









Mound in Stevinus crater


A fractured mound inside Stevinus crater. This may have resulted from squeeze-up of molten rock in the impact that formed the crater. The mound is about 2 miles wide. Stevinus can be seen in small telescopes, although our view is at an angle, Stevinus being near the Moon's southwestern limb. The central peak can be spotted. The mound is only about 1.6 arcseconds in diameter and may just barely be detected in some amateur images. The best time to observe Stevinus is three days after New Moon or two days after Full Moon, with a favorable libration. See details about this image.

Stereoscopic pair of Stevinus mound


















Location of Stevinus crater
Location of Stevinus crater. South is up.







Location of Stevinus dome
Location of the dome within Stevinus crater. North is up.













Wallach crater

Wallach is located in Mare Tranquillitatis. The asteroid or comet that hit the basaltic surface stirred up brighter material from underneath. Wallach is about three miles in diameter. This image was taken from an altitude of about 58 miles. A small telescope with good seeing can pick it out from the mostly flat floor of the mare using higher powers. The best time to observe Wallach is five days after New Moon or four days after Full Moon. See details about this image.


Stereoscopic pair of Wallach crater

















Location of Wallach crater
Wallach's location in Mare Tranquillitatis. South is up.













Hell Q crater


One of the many satellite craters (smaller craters near a named crater) named after Hungarian astronomer Maximilian Hell, Hell Q is a very young crater only about 2 miles in diameter. At only 1.8 arcseconds in apparent size, Hell Q requires a 6-inch or larger scope with higher power. The best time to observe it is one day after First Quarter or Last Quarter. See details about this image.


Stereoscopic pair of Hell Q crater

















Location of Hell Q crater
Hell Q location. The crater Tycho is just above  center on the right, near the Terminator. South is up.











Tycho

The 53-mile-wide crater Tycho has a large and prominent ray system. This oblique image was taken from an altitude of about 37 miles. The west wall on the far side in the image is more than 14,000 feet high. Tycho is an easy target in any telescope, best observed one day after First Quarter or Last Quarter. The bright rays are most prominent around Full Moon, however. See details about this image.

Stereoscopic pair of Tycho crater











The central peak of Tycho. The image is about 3/4 of a mile wide. The boulder on top is about 100 yards wide. See details about this image.

Stereoscopic pair of central peak of Tycho crater


















Lichtenberg B

Lichtenberg B is a young three-mile-wide crater located in Oceanus Procellarum. The ejecta darkens over time, so the presence of bright ejecta is an indicator that the crater is relatively young. Lichtenberg B can be spotted with small telescopes. Being very close to the northeastern limb, it is best observed six days after First Quarter or five days after Last Quarter using higher powers. See details about this image.

Stereoscopic pair of Lichtenberg B crater








Location of Lichtenberg B crater
Lichtenberg B location in Oceanus Procellarum













Earth over Compton Crater

Taken at 83 miles altitude, the Earth appears over the far side crater Compton. See details about this image.

Stereoscopic pair of Earth over Compton crater




Thursday, September 19, 2024

New Binocular Space Walk audio guide - Clusters in Cassiopeia and Perseus

I've added a new Binocular Space Walk audio guide, "Cruising for Clusters in Cassiopeia and Perseus." The guided tour takes you through the northern constellations Cassiopeia and Perseus to find 16 of the brightest open clusters in that part of the sky, as viewed from mid-latitudes in the northern hemisphere. It lasts about half an hour, but provides many opportunities to pause the recording to admire the objects and take breaks. Here's the link to the page, which is also available under Quick Hops on the right. Enjoy!

Binocular Space Walk - Cruising for Clusters in Cassiopeia and Perseus

Wednesday, September 18, 2024

Eyepiece cheat codes: Observing Jupiter and Saturn

Eyepiece cheat codes logo
Jupiter and Saturn, and sometimes Mars, are the planets that will yield the most detail to backyard astronomers. Not only are they bright, but they are large enough for even the smallest telescopes to see them as balls with shading and details. And of course, there are Saturn's rings! Mars generally needs to be at a favorable opposition to see surface details well. 

Jupiter has its four Galilean moons and Saturn has between two and seven moons accessible to typical backyard telescopes. The moons of Mars are generally too close to the planet to spot except when Mars is close to opposition and you have a steady atmosphere with good equipment. 

A night with a steady atmosphere—good "seeing"—will allow you to have much better views than a night where the seeing is soft, turbulent, or mushy. This is probably the single most important factor in how sharp the view will be. Try to observe when the planet is highest above the horizon. Viewing through a lot of "soup" at low altitude will also make for disappointing views, even on a night of good seeing. Heat rising from rooftops, asphalt, and concrete also wreaks havoc with seeing.

If you are observing with a Newtonian reflector, the image will be rotated 180 degrees (generally south is up). In a refractor or Cassegrain with a mirror diagonal the view will be mirror reversed (north up, but mirror reversed). See this explanation of directions in the telescope.

Jupiter

Io and its shadow transits Jupiter
A complete novice can expect to see two main cloud bands on Jupiter and its four Galilean moons. With more practice, not only the South and North Equatorial Belts (SEB and NEB), but temperate belts in each hemisphere may also sometimes come into view, as well as darkened polar areas. 

In addition, features such as festoons, barges, and other spots that represent the turbulent swirls and storms in Jupiter's upper atmosphere become visible with practice and good seeing. 

The Great Red Spot is also sometimes visible when it is rotated towards us, although in recent years it has become rather wimpy in its size and color compared to previous decades. Look at some Jupiter images to see the types of features to look for.

Above: The moon Io and its shadow visible against the cloud tops of Jupiter. Image by Steve Hill, CC by 2.0, via Flickr

Below: The four Galilean moons are aligned on one side of Jupiter in this image by Ivana Peranic, CC by 2.0, via Jeremy Keith/Flickr.

Jupiter and its four Galilean moons
Jupiter's Galilean moons—those that Galileo was able to see in his tiny refractor: Ganymede, Callisto, Io, and Europa—are the only moons, out of the currently identified 95 Jovian moons, that are visible to amateur observers, and can even be spotted in binoculars. Because their orbits are well known, predictions as to transits across the face of the planet and the corresponding shadows, disappearances and reappearances behind the planet or its shadow, and even occasional occultations and eclipses of one moon by another are available. You can plan an observing session to add these to the interesting details you can see in your telescope. 

The easiest are the shadow transits, which show up as dark black dots on the face of Jupiter. The moons themselves are more difficult to see when they pass in front of the planet, and much depends on the level of contrast with the cloud deck below them. I have seen them many times in my 4.5-inch reflector, but have been unable to see them just as many times. The best time to see them is when they are right on Jupiter's limb or just off the limb. Then they show up as tiny disks. Compare the size to the apparent disks of the other moons against the dark sky away from the planet and you'll see how much smaller they actually are.

Averted vision is unnecessary for Jupiter and its moons. In fact, you'll see the most by looking directly at any feature. Bore your vision into the feature, almost as if you are looking through it, to get the most detail to register. Relax your eye and just let the detail burn into your retina. Really stare into it!

Sketching the cloud belts and swirls that you see can really help you focus on the details. You don't always have to sketch what you see, but try it a few times and you'll be surprised at the amount of detail that is actually visible. You may not see it all at the same time, the same with deep sky observing, but you will build up a complete picture with fragmented glimpses. This teaches you to place a detail within the greater context and you'll also see how the features slowly traverse the globe of the planet in an (astronomical) westward direction as Jupiter completes a full rotation in less than 10 hours—the fastest rotating planet in the solar system. For more on observing Jupiter, I recommend How to Observe Jupiter Through a Telescope by BBC Sky At Night Magazine.


Saturn

Saturn
Of all the sights a beginner can see in the telescope, Saturn is probably the most striking. When I show it to people at public outreach events, most people are thrilled and some even question whether what they are seeing is real.

While Saturn doesn't show nearly the same amount of detail as Jupiter, and it's remarkably smaller in the eyepiece, the sheer beauty and uniqueness of the planet will keep you coming back whenever you can. Something about the rings is precious. Really.

Above: Saturn by John Spade, CC by 2.0, via Flickr


Montage showing the ring tilt of Saturn sequentially
The rings change their tilt over the years, and with Saturn now in the evening sky, the rings are nearly edge-on. This makes it difficult to see the major feature in the rings, the Cassini Division. This thin dark lane is sometimes visible on nights of excellent seeing with the rings tilted towards or away from us at a significant angle. Look for it at the outward ends of the rings, where they become more visible because they begin to curve the other direction and the gap is seen at its fullest width. This gap that appears so tiny to us is actually almost 3,000 miles wide! The next ring plane crossing is in March 2025, when the rings, being an average of only about 30 feet thick, become invisible in our telescopes. The Cassini Division may have to wait.

Above: Saturn's varying ring tilt, image by NASA and the Hubble Heritage Team (STScI/AURA), CC by 2.0, via Flickr. Cassini Division label added.

If you look carefully you will usually see a slightly darker band around Saturn and perhaps some subtle shading elsewhere, especially at the poles. Saturn is much smoother than Jupiter, but it does have very infrequent storms visible in our telescopes, such as the great white spot of 2011.

For Saturn's moons, you'll have to use averted vision for all except the largest, Titan, and Iapetus when it is furthest out on the western side of Saturn and its bright icy side is turned toward Earth. Iapetus strays pretty far from Saturn in its wide orbit and can easily be confused with background stars. The inner moons are dimmer, but with good seeing, patience, and a telescope of around 4 inches or more, you should be able to pick out Rhea, Tethys, Dione, and possibly Enceladus. Mimas is quite difficult, Hyperion requires a larger telescope of 10 inches or so, and you won't have a chance at any of the other moons of Saturn, which currently number 146 and counting [Mar. 2025 update: now 274 and counting!].

Jupiter and Saturn observing resources:


Help! I Can't See Detail on the Planets! (excellent article on the pitfalls of observing the planets)

Cloudy Nights Planet Gallery (more recent images at top)

Cloudy Nights Major and Minor Planetary Imaging thread (latest images)

Online interactive observing tool for Jupiter's Moons (Sky & Telescope)

Great Red Spot transit times (Sky & Telescope) (when it crosses the planet's central meridian)

Online interactive observing tool for Saturn's Moons (Sky & Telescope)

Apps:

Moons of Jupiter and Saturn (Android)

JupitersMoons (iOS)

SaturnsMoons (iOS)

Sunday, September 1, 2024

Mounting a RACI finderscope on a collapsible tabletop telescope


I recently bought a Sky-Watcher Virtuoso GTi 150P tabletop 150mm (6-inch) telescope. This is a slightly larger variation, with a go-to mount, of a popular design sold by Astronomers Without Borders as the OneSky, a 130mm (5-inch) altitude-azimuth mounted collapsible tabletop telescope, shown at left.

These telescopes have a Vixen-style dovetail bar attached to the solid part of the tube—the green thing in the pictures of my telescope below. This is how the tube attaches to the mount, which has a Dobsonian style groundboard for the azimuth (side to side) axis and a half-fork with dovetail saddle for the altitude (up and down) axis. The tube can be removed from the saddle and clamped back on with a single threaded knob, the knob sticking up from the blue tube in the picture of the OneSky, making this portable design even more portable.


The problem

For finding objects, or in the case of the go-to model, aligning the mount or finding objects when the go-to isn't cutting it, the scopes are equipped with a straight-through red dot finder that projects a red dot on a window in front of the stars. A clever design with many variations, but like some people, I have trouble—no, make that pain—bending my neck enough to comfortably look through one, especially at objects high in the sky. 

On my other two scopes I have added azimuth circles and a digital angle gauge to find objects by looking up their alt-az coordinates in an app like Sky Safari Pro, moving the scope so that the coordinates are set on the azimuth circle and the gauge, and then using a right angle correct image (RACI) finderscope to zero in on the target. A RACI finder doesn’t require neck contortions and shows a correctly oriented view like you would see in binoculars.

I wanted to add a RACI finder to the Sky-Watcher tabletop telescope, but the problem is that the front ring that holds the secondary mirror and focuser is extended out on two truss tubes so that the whole front half can collapse into the solid rear half that holds the primary mirror, making it quite compact. There is no good place to add a finder on the front ring and it would make the scope quite front-heavy, requiring some sort of counterweight for manual operation. Others have added reinforcement to the front plastic ring or have drilled holes in the tube to add a finderscope, but I didn’t want to do either of these things. 


The solution

Finished finderscope mount on the telescope.
I added a universal dovetail shoe (base) to a block of wood attached to the scope's dovetail bar (the green thing) and swap my RACI finder between my 4.5-inch and this telescope. Looking at the design, the long dovetail bar attached to the telescope tube has two channels that run its length and a single 1/4-20 threaded hole close to the front end of the bar. The hole is presumably for mounting on a tripod, but it’s at a very poor location for balance. I had seen others mount a laser pointer and finder on that part of the dovetail bar, so I experimented with mounting a Svbony SV182 6x30 RACI finder that I have on my 4.5-inch reflector. I zip tied it in place to see how it worked. The problem was that, sticking out straight from the dovetail bar, the finder was too far from the observer’s position and I had to get up and either lean over or walk around the back of the scope to the other side to use it.

If I were to fasten a block of wood to the end of the dovetail bar at a 90 degree angle, then I could mount the RACI finder on the end of it, bringing the eyepiece to a much better position, even better than if I had drilled a couple of holes in the solid tube to mount it. After doing just that, I noted a post on the OneSky megathread on Cloudy Nights that did something similar, but by drilling and tapping a dovetail clamp instead of using a block of wood. Same end result.

Finderscope with updated forward mount extension
10-19-2024 Update: I wasn't happy with how far I had to scrunch down to look through the finder at or near the zenith, so I added an 8-1/2" extension bar made out of a piece of 1x2 furring strip where the dovetail shoe was and put the dovetail shoe on the end of the new bar, moving the finderscope forward and closer to the eyepiece. Wood screws all around. Shifts the balance slightly, but I just move the scope down the dovetail bar a small amount to compensate.


Here’s how to do it

[Note: See 10-19-204 updates below for an improved version that puts the finder closer to the eyepiece.] I cut all the pieces using a basic mitre box and a hand saw.

Finished finderscope mount off the telescope with finder mounted.
I cut a 5” piece of 2x2 baluster (vertical railing piece) that I had left over from making the legs for the telescope’s table mount. I cut a 45 degree corner on one end so I wouldn’t have a sharp corner sticking out. These balusters tend to vary slightly in cross section width, so I checked a few pieces before I found one where the dovetail finder shoe, or base, fits tightly in one direction—one more way to make it even more solid. Note: I used balusters rather than the 8’ lengths of 2x2 that they have because the balusters tend not to be as warped as the long pieces and they were actually cheaper per foot.

I glued and screwed two small pieces of wood to the block to sit in the bar channels and keep the block from rotating on the single bolt. I cut the two little pieces from a large size paint stirring stick (1/4” thick). The pieces are 7/16” wide and 2-1/4” long. I sanded them so they fit tightly into the bar channels.


This side will face the observer sitting at the telescope.

Close up of the end of the dovetail rail on the telescope.
I dry fit the block and the two channel pieces to make sure they fit tightly in the dovetail bar. There are two screws in the dovetail bar at the bottom of each channel 1/8” from the front end of the bar. The block would need to sit behind these screws with the channel pieces butting up against them to add stability. I marked where the bolt would go through the block into the dovetail bar and also where I would need to glue the small channel pieces that would fit snugly into the two channels in the bar. I had cut them a little long just to give a bit more twist resistance in the channel.

Unpainted finderscope mount with dovetail base attached- back view.
Where the bolt would go through the block and screw into the dovetail bar, I countersank a 3/4” diameter hole about 3/16” deep, enough so the bolt head, with a 5/8” outer diameter - 1/4” inner diameter washer, would be flush or nearly flush with the surface, using a 3/4” Forstner bit. (3/4” because my wrench socket would fit in it so I could tighten the bolt.) You must do this before drilling the hole for the bolt so that the bit can center properly. It’s not essential to countersink the bolt head, but I thought it would be better than having it sticking out, and I recently got the Forstner bit set, so I’m eager to find reasons to use it! I then drilled a 1/4” hole all the way through the block, centered in the 3/4” countersunk hole.

I inserted the two little channel pieces into the channels and pushed them tight up against the screws in the bar channels. I inserted the bolt and tightened it to make sure the fit was good. Then I removed the bolt, put wood glue on the two channel pieces where they would join the block and bolted the block into place. Once the glue had dried for about 45 minutes, I removed the assembly and cleaned off some glue that got on the dovetail bar. It removes easily.

Top view of mount showing dovetail base screwed into top.
The dovetail shoe for the finder has four slots for screws. I screwed it into the top of the block with four 1-1/4” #6 wood screws. Everything looked good, so I took the shoe off the block assembly, painted the block assembly black, reattached the shoe, and attached the whole assembly to the dovetail bar. The shoe stays on the bar and the finderscope is removed for transport. This modification is also entirely reversible with no alteration to the telescope. [Note: With the updated extension, you'll screw the extension bar in here and screw the dovetail shoe to the forward end of the extension bar.]


The finished mount. Note the four screws added to the channel bars. I found glue alone did not hold. Make sure you recess the screw heads into the wood with a countersink bit so they don't scrape the dovetail bar. 








View of telescope with finderscope in place.
The finder is at a more comfortable, although still not optimum, location. I can also fit my head in there to use the red dot if necessary. The scope can rotate through the entire range of altitude motion without anything bumping or binding, but be careful when pointing above 50 degrees, as the additional weight of the finder will want to flip the tube backwards.


Telescope collapsed with mount attached.
Packed up, the finder mount is out of the way and adds very little weight or volume to the overall package. Just loosen the two thumbscrews, slide the finderscope on, and tighten the thumbscrews. 








View from above of telescope collapsed with mount attached.
View from above when collapsed. The finderscope mount does not stick out beyond the round baseboard of the telescope mount. The dovetail shoe is mounted so that the thumbscrews point inward and are less likely to catch on a cover or other item.





Now I can use the RACI finder more easily and swap it between the two telescopes. It's still not an optimum viewing position especially at higher altitudes, although being able to rotate the diagonal on the finderscope helps. But for these collapsible telescopes, this makes a useful addition or alternative to the red dot finder.

Extended mount on the telescope
10-19-2024 Update: The scope with the new extended mount for the finder. Because it sticks out further when the scope is collapsed, I plan on getting a 1-1/2" knob to replace the bolt holding the bracket to the dovetail bar, making it easy to remove for transportation.

Saturday, August 24, 2024

Recording your observations

 
Jupiter-Venus conjunction over houses
Jupiter-Venus conjunction, March 2023

 

July 3, 1990 (Miami, Florida)

Picked out major stars: Vega, Altair, Deneb, Arcturus, Spica, and Antares (near Moon). Found the “Teapot” and figured that was Saturn to the left (west) of it. Mosquitoes were fierce and it’s only July! Looked for M19- too washed out to spot it. Also M4. Traced out some of the constellations. Moon is gibbous—some good crater action on the “tan line”.

That was the first observation I ever recorded. I didn't even have celestial east and west sorted out yet. Not that I hadn't observed the sky with a variety of telescopes, binoculars, or the unaided eye before that. But this was my first year of "getting serious" with amateur astronomy.


But how serious are you about Sirius?

It's what you make it. It's a hobby. For some people it's a passion. But it's still a hobby. Most of your observations matter only to you, so consider that, when and if you record them. I do strongly suggest you keep some kind of observing log, for the following reasons:

  • It will jog your memory to bring back specific nights and events
  • You can compare observations made at different times, in different skies, through different instruments
  • It's interesting to see your progress in the hobby, and your failures
  • It will tell you if you've observed something before or if it's new to you
  • You'll remember people (and critters) you would otherwise have forgotten

That's just a few, and it really varies depending upon the person.

I can only tell you how I log my observations. I don't always log details, especially for objects I've seen many times, unless I see something new in them. I like to keep it conversational and not too technical. I like to have fun. I don't like to be bothered recording the seeing, transparency, exact eyepieces and powers I was using, data from a sky quality meter, etc. for every observation. I'll note the sky conditions at the beginning of a session and if they change, as they often do. I keep it simple- who, what, where, and when. I already know the why. See my post on the Comet Shoemaker-Levy 9 impacts on Jupiter log entries to get an idea of what I put in there and how a log makes a great memento of a memorable observing session or event.


Two bins

My observing records end up in two bins: an observing log in narrative form, which includes notes taken while at the eyepiece that I then extract from the log and group together by object over time in a separate collection of notes files.

A page from my observing log
My actual observing log, as in the example above and at left, is a session by session narrative. I keep it in a series of Microsoft Word compatible documents, usually one document per year or half year, depending on how much observing I've done, and I'll add images from the internet for many of the objects. 

I note the situation, the people, animal sounds, big gusts of wind, spectacular lightning on the horizon—all those things that bring back the memory like it was yesterday. I'll also make notes at the eyepiece about specific objects. At the beginning of each session, I note the date, day of the week, location, and what equipment I'm observing with.


Periodically I'll extract the notes on specific objects, which I highlight in bold in the log to make them easier to find, and collect them in text files, which I call my observing notes. With this collection of notes, I can look up an object and compare what I'm currently seeing with what I have seen in the past from a variety of locations, in different sky conditions, and with different instruments. I aggregate the notes for each object into a single entry, as in the following example:

Veil Nebula (western portion), NGC 6960

Oct. 13-14, 1993, Chiefland Star Fest, Chiefland, FL
(4.5-inch) Quite bright- tried for dimmer side near the bright star in my scope- only a hint of its brightest part in 100x. Low power would be better if I had it.

Nov. 13-14, 1993, Lake Kissimmee State Park Star Party, FL
(10-inch) Nice view of the fainter section in the 10-inch SCT. Very bright with the nebula filter. Seems like there's a dark lane down the center of the nebulosity (this is the W section). E end visible with the filter.

Sep. 24-25, 2003, Skyline Drive, Shenandoah National Park
(4.5-inch) It's just such a nice transparent night I had to go for the Veil Nebula, and sure enough, it's pretty easy to see around 52 Cygni on both sides, not just the one brighter side, and I can see more than I usually can in those areas. I can see the other segment on the opposite side (NGC 6992) in the finderscope! It shows up nicely in 50x. I gotta say that's about as well as I've seen the Veil show up in this scope. I can trace the whole crescent shape of 6992 for at least 2 fields of view in 50x (almost 2 degrees).

...and so on.

Decades ago I wrote my notes at the eyepiece in pencil or pen. Then I used a handheld tape recorder. Then a digital recorder. Now I dictate in Google Keep using the voice typing feature, copy and paste into my log at a later date, and clean up the dictation errors. Google voice typing has particular difficulty with certain astronomical names, such as when I say "Ophiuchus," and it writes "all for you because," "ophelucas" (huh?), or the usual "off of Lucas." I'm used to correcting such phrases such as "and you see," for "NGC." A recent favorite is "IHOP address" for Saturn's moon Iapetus. 


Find a way to make it easy


Ideally, I would have a charting app at the telescope in which I could click on an object and it would bring up these observing notes for that object. Sky Safari falls short for me in that respect, in that it forces you to organize your notes by observing session, much like my observing log. But I want to see all my notes over the years for a single object in one place. I've tried to use one Sky Safari "session" to put all the observations for a single object in the comments, but the box has no scroll bar, there's no way to add images, and it's very clunky. 

I just wanted a simple app that I can update easily, add images, and most important, import and export through a standard format. 

Memento Database screenshot of Astro Log





I think I found just that in the Memento Database app. I started with an astro log template available through the app and modified it to include just two fields: notes and images. While it requires going between the Sky Safari and Memento apps, it's a pretty good second best solution. I use the app Twilight to dim and redden the screen while observing. iPhones do this natively.








Memento Database screenshot for M61 log entry tab






I was able to export my notes from Sky Safari on the 1200+ objects I've recorded over the years, then import them to Memento, all via a .csv file. Cool beans. 










Memento Database screenshot of M61 image tab






I downloaded images of the objects, resized them to keep the database small (the Memento cloud has 100MB free storage), and attached them to each file. Tedious, but fun and it helps me remember some of the objects I haven't observed in a while and should revisit. I like having images at the eyepiece to help determine if what I think I'm seeing is actually there.







Apps will come and go, so one of the keys is to be able to backup your notes and store them in a standard format like text or xml. I figure text is about as standard as you can get, so I stick to that.

Sometimes I just like to read through my old logs on my computer, and now the notes are portable so I can look them up at the eyepiece and even browse them while I'm waiting at the doctor's office. I did that today, reading my observing notes on the Comet Shoemaker-Levy 9 impacts on Jupiter, which were 30 years ago. I cherish the memories that I've preserved through my observing log and notes. How much would I remember without them?

Thursday, August 15, 2024

Why does finding things easily have to be so hard?

Screen saying "404, Object not found. Try another universe."
In a previous post, I noted that I had gone over to the "Dark Side" and bought a 6-inch tabletop reflector with go-to, the ability to punch in an object and have the motor slew the telescope to it. This is a Sky-Watcher Virtuoso GTi 150P.

Well, so far I'm not impressed with the Dark Side. Like most tech gear, I have a love-hate relationship with it. I love it when it works. When it doesn't, which seems more and more of the time now, I hate it. I can't count the number of times just in the few weeks that I've had it that I wished I could just push the scope where I want it to go, like a manual dob. That always works. Always.

So what are the issues? For one thing, you need two suitable stars to do the initial alignment. These are selectable from a list. In a partly to mostly cloudy sky, which is common around here, two suitable stars may not both be visible at the same time. Understandably a limitation of the sky conditions. But if they are visible, the scope may slew many degrees away from the target star, so you need to choose only the brightest stars that are easiest to navigate to manually and recognize in the eyepiece as the correct star. 

Then there's the accuracy. Maybe because it's a cheaper mount (the scope retails for $470 and I paid even less on sale), but an initial alignment almost never lasts the whole observing session, which for me is usually between two and four hours. Sometimes, despite leveling, centering the alignment stars, and doing all the required tasks, the first object I punch in after alignment is still several degrees off. Occasionally it's right in the middle, but most of the time it's either on the edge if I'm lucky or somewhat outside a low power (30x) field of view. When it's several degrees off, I can starhop my way over to it with the help of the Sky Safari chart. Again, somewhat of a limitation of the technology.

Then there are the random take-offs. I'll have an object in view and then as I am watching, with the phone on the table, the scope suddenly decides it wants to look at something else and slews on its own. Hmm.

How about connection drop outs? This scope has WiFi, to which the Synscan app connects so you can control it with your phone. Synscan is very rudimentary in its interface for selecting objects (and the font for that function is inexplicably small). So I tried using Sky Safari to select and go-to the objects I want to look at. At first things were great, except that Synscan would drop the connection every 15 minutes unless it was in the foreground. Despite ensuring the Android settings would prevent this, it still did it. I could live with that. 

But then either Synscan or Sky Safari must have done an update (à la CrowdStrike), and Sky Safari would no longer connect: the Gray Screen of Death (GSOD) in the screenshot. So I used the apps separately, selecting an object in Sky Safari and pointing to it with Synscan, then going back and forth between apps to actually get it in the field. This is supposed to be the easy way of finding stuff? I later found that if I just move Synscan to the foreground and then back to Sky Safari, the latter will reconnect. But...really?

Snarling dog
Lastly, I find that having to look down and press buttons on a cell phone when I'm observing is distracting and clunky. It also doesn't help with maintaining night vision, despite a "night mode" in the app, which is not well implemented. You can slew at different speeds, but it's aggravating to keep overshooting over and over. [1/9/25 update: I picked up a cheap bluetooth mini game controller and it works great. In the cold, I can even keep my hand in my pocket and control the scope. One problem solved.] I tried the "tilt to slew" feature in Sky Safari, whereby you tilt your phone a little one way or the other and the scope slews in response. That is even more masochistic, no matter how slow I set it. Sometimes I give up, loosen the clamps on the axes, and just move it by hand. Always works. But that kind of defeats the purpose of go-to, doesn't it?

Well, by now you either think I'm a total crank, or maybe that go-to is not everything it's cracked up to be. In fact, I have come to the realization that both are true. 

I am now experimenting with using the free progressive web app Astrohopper as my "push-to" way of finding things (see my initial review on Astrohopper here). It works well for that purpose and is more reliable than the go-to. I can still use the tracking once I find an object, and that's my main reason for getting the go-to version over the non-go-to. I can't use straight-through finders anymore due to physical limitations, otherwise I'd still be starhopping, which is the simplest, most reliable, and most rewarding way to navigate with a telescope.

By the way, the scope itself is great. It's the tech part that could use some refining, to say the least. The Synscan Pro app gets a 2.2 star rating on Google Play. The non-pro version only gets 1.7 stars. I may end up staying with Astrohopper as my finding tool, then turn on the tracking. That works. [9/21/2024 Update: I got fed up with the go-to, and Astrohopper seems to not be able to geolocate after browser updates, so I added an azimuth circle to the scope base and use that and my digital angle gauge to navigate now. I only use the tracking, and that is often out of whack, but it's nice when it works. Maybe I'll write up how I did the azimuth circle in a future post.]

Snarling dog image by Albert Leung via Flickr (CC 2.0).

Tuesday, August 6, 2024

New Binocular Space Walk audio guide available

Space Walk Among the Stars logo, a star with legs walking
I've added a new Binocular Space Walk audio guide. This one takes you through the Summer Southern Milky Way, as viewed from mid-latitudes in the northern hemisphere, looking at open clusters, globular clusters, a double star, and a few nebulae. It lasts about half an hour, but provides many opportunities to pause the recording to admire the objects and take breaks. Here's the link to the page, which is also available under Quick Hops on the right. Enjoy!

Binocular Space Walk - Summer Southern Milky Way

Friday, August 2, 2024

My favorite observing accessory

White duct tape. 

Okay, maybe not my favorite, but up there in the Top 10.

Why? Because it helps you find stuff at night. Not up there, down here. We worry about finding stuff in the sky, but when you drop something on the ground or walk into something in the dark, you’ll appreciate that being able to see stuff on Earth is almost as important as seeing stuff in the sky.

Few sites are so dark you won't see a piece of white duct tape more easily than something darker colored. I always keep a roll in the car.


Where to use it:

  • On any equipment you don't want people bumping into in the dark, especially at public events with people unfamiliar with the size and shape of astro gear.
  • Lens caps. Many lens caps are black. Drop one in the grass and you will need to turn a light on, not something you want to do unless you have to when you are observing. All my eyepiece caps and telescope covers have little squares of white duct tape on both sides so I can find them easily in the dark. Kudos to those companies that make the clear caps, but even they can benefit from a piece of white duct tape.
  • Marking indicators. I have this thing about always forgetting to turn off red-dot finders. Always. So I put a couple of small pieces of white duct tape on the knob that turns it off. When they line up, it's off. Where to put the scope in the dovetail saddle? Mark it with white duct tape. Where does the telescope cap line up? Where do I grab something at night? White duct tape.
  • At one site, we have a wooden fence gate that can be in various stages of open. I will invariably walk into it in the dark. Slap a piece of white duct tape on it.
  • At another site, there was a big gopher hole. I stepped in it. You can be seriously injured by doing something like that. A stick with a piece of white duct tape on it kept me out of the hospital.
  • Black telescope? Manufacturers love black telescopes, black binoculars, black cameras, black cases, black everything. A few strategically placed pieces of white duct tape will make it less likely to be stepped on, bumped, or run into at night, by you or someone else.
  • Red LED flashlight. If it's dark colored, it's not going to do you much good if you can't find it in the dark. White duct tape.
And there's not much in the world you can't fix temporarily with duct tape, so it's always good to have it around.

I'm sure I've forgotten many other uses for it, and I'm sure you can come up with others.