Thursday, April 14, 2022

Saturn Shadow Play

Saturn is gradually climbing out of the Sun's glare in the pre-dawn sky, and by month's end it clears 20° in altitude before civil twilight starts. The ringed planet is both spectacular and subdued in the eyepiece. The rings, even if beginning to close up compared to the last few years, are just an amazing sight. The globe, however, is subtle with its pastel colors and gradually darkening bands as you move north to the darker NPR. For this reason most of us will admire the planet for a minute or two before moving on to another target of interest.

A unique aspect to Saturn is the shadow play of globe and rings. The most obvious is the shadow of the globe cast on the rings as they arc behind the planet. Prior to opposition it is seen on the preceding (western) limb, reaching maximum visibility at western quadrature (which will be May 16th this year). It gradually wanes until it is invisible at opposition and then emerges on the eastern limb, growing until reaching eastern quadrature. 

Saturn, a month after opposition, shadow on eastern limb

A little harder to detect at times (and more complicated to predict) is the shadow of the rings falling upon the globe. The geometry is multifactorial in predicting where (or if) we get to see the rings' shadow; the extent to which the rings are tilted and the angle between Earth and the ringed planet can influence it. In general, the shadow of the rings on the planet is obscured when they are "fully open" and then gradually becomes more visible (and thinner) as we head towards Saturnian equinox. 

We're entering the period where the rings' shadow is beginning to peek out along the southern border of the rings. Earlier this month there was an interesting observation submitted to ALPO by Clyde Foster, an accomplished planetary imager from South Africa. In it he noted a bright white speck at the intersection of  the western limb and southern edge of the rings (below). At first he considered it as an artifact, but then Martin Lewis from England postulated that this actually represented us seeing sunlight passing through the Cassini Division onto the planet.


Mr. Lewis' analysis was greatly aided by the tool known as WinJUPOS, a software program that handles the calculations of Solar System object geometry (among other marvelous functions). The graphical representation of Saturn for early April when Clyde made his observation showed that the ring gap was ever so slightly peeking out from under the rings on the western limb. 

Using WinJUPOS to examine the position of the shadow reveals that the "Cassini Gap Sunshine" will continue to emerge from under the rings on the western limb for several more weeks, reaching its maximum exposure as Saturn reaches western quadrature May 16th. It then begins to retreat until it is tucked up under the rings and lost from view by mid-June. The animated GIF below shows the ebb and flow of the CGS. 




Animation showing the Cassini Gap Sunshine (CGS) visibility

I suspect that this might be imaged with a telescope as small as 6" in aperture, and possibly even seen visually. Steady seeing will be a huge determinant in your success, but the good news is that at dawn we often find some of the steadiest conditions and Saturn will be near its culmination in the sky. Also be sure to allow enough time for the optics to cool to the ambient temperature, especially with a Newtonian system. I for one am hoping to see this CGS in mid-May with my 10" reflector and will share any success on the HAL Google Group. 

And, in full disclosure, seeing the CGS should be easier next spring as the rings close up even further. Sure, it's going to require a little effort to see if you can observe or capture this first opportunity at seeing the sunlight filtering through the Cassini Division on the cream-colored cloud tops below. It is guaranteed to test your planetary observing (or imaging) skills to snag it like Clyde. But then again, isn't testing your skills at the eyepiece a part of what makes this hobby an enduring passion for so many of us?

Thursday, March 17, 2022

A Filtered Experience

The topic for the HAL meeting this evening was "filters", which is a pretty big topic! After all, we have filters for visual use vs. imaging use, and then filters for specific targets from faint DSO to our brilliant Sun. Hopefully I provided a little insight at the session based on my personal experiences, especially as to planetary observing.

Back in '65 when I got my first scope, a classic 60mm refractor with .965" high-powered eyepiece, I knew one thing for sure that I really wanted to see was Jupiter's Great Red Spot. The scope showed the planet as a fuzzy disk with slight rainbow fringe, perhaps a stripe or two upon it, but no GRS in sight on the multiple occasions I target the giant planet. Somewhere - probably a library book that I had borrowed - I read how a blue filter would darken the GRS and therefore make it stand out better. Clearly that would make my target materialize in the eyepiece!

My dad was a local pharmacist and contracted with a camera shop down on Falls Road to provide film developing service for his customers. He was supportive of my hobby (so long as I didn't get the foolish idea that I could make a living looking at stars) and helped me to get a 2x2"Wratten 80A blue gelatin sheet and a mounting ring for the filter that was just a little smaller than the internal diameter of the refractor's dew shield. I carefully cut out my circle of blue, mounted it in the holder, dropped it into the front end of the scope and then waited for the next clear night. 

The view of Jupiter was quite pretty with its blue hue, but even after several attempts on different nights I still could see no GRS. (Of course, I am assuming that just by the odds I would have seen it on one of those evenings. I had not discovered Sky & Telescope with its listing of GRS transits yet, and online lookup would have been the glorious stuff of science fiction in the mid-60s). While filters lost a little of their charm from the experience, I felt that the principle was certainly sound. Reddish features would have their light blocked by a complementary blue filter, making them darker and easier to see. I began to suspect (correctly) that it was more an issue of small aperture than filter failure.


When I graduated to my 6" Newtonian I was finally able to catch sight of the Great Red Spot one evening without a filter. It had fairly good intensity back in the late 60's - similar to its appearance now. The availability of a glass filter that would screw into the bottom of the eyepiece was (as far as I knew) nonexistent. So no filters for visual inspection of my planetary quarry at that point in time.

But by now I was starting to play with using a second-hand Minolta range-finder camera to take pictures using the afocal method. Talk about a tedious hit or miss approach! You had to line up the camera over the eyepiece at where you think you are at focus, then hopefully get the planet in the field just based on the 6x30 finder scope, and finally snap the picture with a cable release while hopefully not jiggling the scope. Despite all that, I had occasional success with the technique. It also drove me to learn how to do my own B&W development rather than watch the photo lab assume nothing was on the roll of film and slice right through my field when trimming the negatives.

By this point I'm a HS freshman, networking with fellow amateurs at the Baltimore Astronomical Society and with enough pocket money from working at the pharmacy to buy some hobby stuff. I got another filter holder that would attach to the front of the Minolta and outfitted it with a Wratten blue gelatin. And then on a May evening in 1970 I did it - I actually captured the GRS photographically, a dark spot near the planet's central meridian. It was an OMG!! moment as I inspected that roll of film while hanging it up to dry. 

Jupiter - afocal method with 6" f/8 RV-6 at 140x
using Minolta camera with 80A filter

It was probably shortly after this that I began to find retailers of glass Wratten filters that we are so familiar with today. I started my collection with a #80A blue and it gradually expanded like a rainbow. Over the years I have found that, for visual planetary observing, they are not going the wow you like an O-III filter can do on an emission nebula. But they can be helpful if you approach their potential realistically, i.e., a tool that can improve the contrast of notoriously low-contrast planetary features. In addition, they do not cost an arm and a leg (at least not for the basic Wratten glass filters that almost any good astronomical supply house will carry).

Although I am given over more to imaging a planet rather than sketching it these days, I still do enjoy at the end of the session taking a few minutes to gaze upon my target before putting away the equipment. In doing so I'll almost always apply a filter in an effort to see the most that I can. Here are my common go-to filters using my 10" reflector (if you have a smaller scope then a corresponding filter with higher transmission rate may be a better fit):

The brilliance of our sister planet Venus means you have to knock down the glare significantly to be able to appreciate the disk. I often use a #47 Violet with only 13% transmission to accomplish that. The most I have been able to make out on Venus is some brightening at one or both polar regions ("cusp caps").

When Mars comes calling every other year it is a fun target and arguably one of the best for filter enhancement. The #80A medium blue is helpful in seeing the polar ice caps and lighter orthographic clouds that sometimes form. A light red #23A helps to darken the albedo features and boost their contrast. I have also found a deep yellow #15 to be a nice choice to reduce the planet's brightness and boost overall contrast.

Mars through my 6" f/8 RV-6 & Red #23A filter 10/7/2020

 

Jupiter is an absolute favorite for me given how dynamic it is. I have always found a yellow filter (#15 deep yellow or #11 yellow) as a good, all purpose aid to improving the contrast of the belts against the lighter zones. A pale blue (#82A) or medium blue (#80A) are helpful as well, especially with the Great Red Spot (the pale blue improves the contrast yet you can still pick out some of the red overtones to it).

While not as subtle as features among Venusian cloud tops, Saturn offers delicate features with its gradually darkening belts as you move from bright equatorial zone to dark polar hexagon. Again, a yellow filter seems to work well for improving the contrast a bit on the globe. 

Based on a very interesting "consumer reports" article on Cloudy Nights where author William A. Paolini compared multiple filters to find the ones that seemed to be the best for accentuating planetary detail, I have recently purchased a Baader Contrast-Booster filter. Now I just need to wait for this fall when we'll have Mars, Jupiter, and Saturn available for my own assessment of how well it does. 

If planetary observation is something you enjoy then you really should play around with some filters to see if they help you pick out some of the subtler details. Most retailers offer the Wratten color filters for under $20, and so long as you are not expecting miracles to happen, you'll likely find them an interesting and enjoyable accessory to have in your observing armamentarium. 

Saturday, February 26, 2022

A Tangent on Venus

In last month's blog I chronicled my effort to see Venus as it skirted north of the Sun during its inferior conjunction. It was not a particularly easy task but certainly doable in clear skies. This month I'm doing a little armchair astronomy because that experience made me ponder when circumstances would be at their best to capture Venus as it moves between our home planet and the Sun.

Trigger warning - math is used in this blog post!

While you could spend time scouring the Internet to find the maximum distance that Venus can lie from the Sun during an inferior conjunction, where's the fun in that for anyone with geek tendencies? If we dust off our trigonometry and get some basic orbital elements we should be able to swag an answer to our question. 

It always helps to define some terms before solving the problem. The ecliptic is the plane in which the Earth orbits the Sun. In considering the orbits of other members of our Solar System we can speak of the inclination (tilt) of their orbit relative to Earth's orbit. Those two planes will intersect at two nodes (points). One node (the descending node ☋) would be when the neighboring planet is heading south when it crosses through our orbital plane, while the other (ascending node ☊) it is northbound. What is curious is that there does not seem to be a term for the point 90° farther along the orbit, where the planet would lie maximally above or below our ecliptic. For the sake of discussion, I'll call the point in the orbit where the planet lies at its greatest distance above (north) of the ecliptic as its cresting node and its southern counterpart as its sinking node.

Step 1: How far above the ecliptic does Venus lie when at its cresting (or sinking) node?  

We can readily find Venus' inclination to the ecliptic (3.4°) as well as its average distance from the Sun (a) and then calculate how far above the plane it lies (b) using basic trig:

b = a ÷ cot(θ)

Plugging in to the formula:

a (Venus-Sun distance) : 108 million km

cotangent of 3.4° = 16.8

b = 108/16.8 = 6.4 million km

Step 2: Knowing how high above the ecliptic plane Venus lies at cresting/sinking node and the distance between Earth and Venus at inferior conjunction, we can calculate the angle as seen from Earth for how far above the Sun Venus will appear in the sky: 



θ = tan-1(b ÷ c)

b (height of Venus above ecliptic): 6.4 million km

c (Earth-Venus at Inferior Conjunction): 42 million km 

tangent ratio: 6.4 ÷ 42 = 0.1524

arctan(0.1524) = 8.67°

Wow - that is almost the length of the upper bowl of Big Dipper. My observation back in January had a distance of 4.8°, a little better than half the best it could be. So having determined the "what", let's turn our attention to "when" we would see one of these inferior conjunctions where Venus is at its cresting node.

This June will mark a decade since the last time Venus transited the Sun. As you may know, these events are quite rare, occurring as a set of transits 8 years apart. In the context of our ecliptic plane and Venus' plane, the inferior conjunction must occur while Venus is moving through its ascending or descending node in order for us to see a transit. And that is why they are confined to a few days around June 8th (as it reaches its descending node) or December 8th (ascending node). If our cresting node can reasonably be assumed to occur midway between June 8 and December 8, the approximate date for it would be on March 8th. As a result, for those of us in the northern hemisphere, an early springtime inferior conjunction will be our best opportunity to catch a glimpse of our sister planet directly above the Sun. 

From a listing of past and upcoming inferior conjunctions, we have the following ones that occur in March:

March Inferior Conjunctions
3/30/2001
3/29/2009
3/25/2017
3/23/2025
3/20/2033
3/18/2041
3/15/2049

Searching online for the inferior conjunction that happens March 23, 2025 we find the difference in Declination between Venus and the Sun will be + 7.5° - adhering pretty well to our predictions. With any luck I'll be around and have a clear day to set up the scope and try yet again to image the event.

A final observation before closing out this post. As discussed in April's 2020 blog when Venus traversed the Pleaides, our sister planet takes just shy of 8 years to return to nearly the same point in our sky. We see that 8 year interval again in the table above where each subsequent inferior conjunction arrives a couple days shy of 8 years. What if we look at the most recent inferior conjunction January 8th and project it out in an unscientific way to estimate its future conjunctions by simply adding 2,920 days repeatedly to it:

January Inferior Conjunctions
1/8/2022
1/6/2030
1/4/2038
1/2/2046
12/31/2053
12/29/2061
12/27/2069
12/25/2077
12/23/2085
12/21/2093
12/20/2101
12/18/2109
12/16/2117

Hmm - the next Transit of Venus is set to occur on December 11, 2117. We didn't land on it exactly because of our estimating shortcut, but there's no doubt that the most recent inferior conjunction is gradually walking the calendar backwards to become the next transit event, gradually losing a little of its northern clearance above the Sun's limb on each conjunction until it finally ends up crossing the orb.

If you have persevered to the end of this geeky blog entry - congratulations! It's probably due in some measure to the fact that, like me and the multitude of ancient astronomers that came before us, you find the patterns and rhythms of the heavens amazing and fascinating to explore.






Sunday, January 9, 2022

Lunchtime Venus

Since late last spring Venus has been an evening star in our skies, shining brilliantly in the southwest. It was not the best of apparitions for those of us at mid-northern latitudes as it hung out in the basement of the zodiac when reaching its greatest distance from the Sun. I only managed a couple of casual observations and a single imaging attempt due to the planet often being obstructed by trees or buildings from my home observing venue.

Like all evening appearances of our sister planet, the transition from evening to morning star is defined by Venus reaching "inferior conjunction." This event, where the planet passes between Earth and the Sun, was set to occur on Saturday, January 8th around 7:40 p.m. our time. If the Earth-Venus-Sun orbital alignment were straight on we would witness Venus transiting the face of our home star at each one of these passages. But, just as we are not treated to a solar eclipse at every new Moon, Venus' orbital inclination of 3° to the ecliptic causes her to glide north or south of the Sun. Only roughly once a century do we get to witness a pair of transits, spaced eight years apart, with the most recent taking place in June of 2012.

This weekend's conjunction saw Venus skirting Sol's northern limb by about 4.5°, leading most websites such as In the Sky to state

At closest approach, Venus will appear at a separation of only 4°51' from the Sun, making it totally unobservable for several weeks while it is lost in the Sun's glare.

S&T Image Credit

In actuality, to describe it as totally unobservable is perhaps a bit of an exaggeration. It's one of those observing challenges that can be done, albeit with great care since even a brief exposure to the Sun's surface through any sort of optical aid can easily damage your retina. I've viewed Venus in the daytime before, both naked eye and with telescope, on numerous occasions, but had never attempted an Inferior Conjunction sighting. With the forecast for conjunction day looking quite good I decided to take up this challenge.

My hope was to actually get an image of the event, so I arose before dawn to mount the 6" reflector and perform an alignment. After battling some passing clouds I finally got the Celestron mount able to slew to a target with reasonable accuracy. I left the drive running and waited for my quarry to rise high enough in the eastern sky to view it. 

By 10:30 a.m. the winter Sun was well placed so I attached the camera and asked the mount to center Venus. I had placed a red filter in the optical path to help boost contrast against the bright blue sky, but the screen was still a bright, featureless canvas. I tried slowly sweeping the area a little bit to no avail. I finally removed the camera and substituted a 16mm eyepiece to see if I could make a visual sighting, but that, too, ended in failure. I reluctantly broke down the equipment and headed inside.

Not quite willing to accept defeat, while eating lunch I plotted my next attack. I considered that Venus should be positioned pretty much at the 12 o'clock position relative to the Sun's disk at this time. What if I positioned myself such that the apex of the neighbor's house blocked old Sol? Would that allow me catch Venus in the sky above the roofline with binoculars? I grabbed my trusty 7x50 Celestron binoculars and headed outside to find out. I swept the area until my arms grew tired with still no sign of the planet. As a last ditch effort I brought out the 15x70 Oberwerk binoculars to see if they might do the trick. After about five minutes - there!! A surprisingly bright, tiny crescent lying on its back was visible above the rooftop. It was a little surprising how clear one could distinguish the crescent shape and how white, like snow, the disk seemed in the blue sky. 

I hurried inside to grab the Canon and telephoto lens in hopes of capturing a shot using the same technique. When I emerged and used the Oberwerks to try to relocate Venus I struggled. Where the heck was it - I had just seen the darn thing. Then fate lent a hand when a jet billowing a contrail behind it crossed the field. Within a few seconds I had identified Venus again. Once the contrail had dissipated, it was again tough to pick out the tiny crescent. A few minutes later another jet deposited its white contrail in the vicinity, and again it became easier to pick up Venus in the field. Thinking about this I suspect that as the field jostled from my unsteady hand the planet moved with the contrail, thus becoming more apparent to my brain. Whatever the actual reason it was an undisputed truth that having the contrail in the field made picking up the planet easier.

In yet another testimony to our eyes' logarithmic response to light, the photos appear to have been a bust as well since exposures long enough to possibly pick up Venus were overexposed. The result is in a field containing a wide range of light intensities, our eyes will provide a good image whereas it is often impossible for the camera to capture it. And although I may have come away with no photographic proof of my success, the experience adds another page in my book of  amateur astronomy that I will have fond memories of.

A digital sketch of Venus & Contrail



 

Sunday, December 19, 2021

Great Expectations

As the holidays unfold, we can be certain that a multitude of shoppers are weighing the decision of putting a telescope under the tree for a loved one. As seasoned amateur astronomers, we often try to provide advice on potential purchases to friends and strangers alike on social media. Increasingly there are good resources made available by the amateur community on what is a good starter scope for the newbie in hopes of avoiding a “hobby killer.”

Unfortunately, the seed of a budding amateur astronomer can be poisoned even more thoroughly than any poor telescope long before the instrument finds its way into their hands. It comes about when they develop expectations that are impossible to meet. It’s often said in business that to “under promise and over deliver” leads to a happy customer, but sadly that axiom is often turned on its head when it comes to starting off exploring the heavens.

APOD from 12/03/2021

Don’t take umbrage, but one of the primary offenders is the experienced amateur astronomer amplified by social media. While it is certainly not done by intent, posting those amazing pictures of what’s up there readily kindles a desire to replicate that. Some folks will also assume that they can actually see that object with their eye, having no understanding of the power of a CMOS chip in gathering up photons. The photo does not come with a disclaimer of how many years the author has been at this, nor the investment they have sunk into their equipment. The uninitiated will assume that the same technological magic they find in their phone will make creating their own picture of the Cygnus Loop a breeze (or at least doable.)

The other, and in my opinion bigger, contributor to inflated expectations is the media. In the good old days, one had a better sense of what sources of news were reputable. If the tabloid in the supermarket checkout line had 72pt type headline declaring “Super Blood Moon to Appear!” you were suspicious. If Sky & Telescope had “Best Lunar Eclipse of Year” you knew you could bank on it. But now, thanks to the digital revolution and lack of standards, anyone can be an author (including your humble blogger) without benefit of an editor. That can be a good thing in making voices heard, but it also opens the door to hyperbole in the pursuit of new content and clicks. You need look no further than the hubbub over Comet Leonard this month. Yes, it has technically been a naked eye object, but only if you were observing from a dark sky venue. For the vast majority of readers Comet Leonard is not going to be visible. I personally could not even catch it with 7x50 binoculars in the pre-dawn sky a couple weeks ago given the light pollution in Towson.


Is this even an actual image of Leonard??

What to do? One of the best things is to afford the curious a chance to actually look through a telescope in a suburban setting. HAL does a great job of this and should be commended for their persistent efforts to host star party events for the public. But you can do some sidewalk astronomy right from your own sidewalk. Maybe instead of hiding out in the darker back yard put the rig out in front of the house shortly after dusk as the neighbors are taking fido for his walk. Let them take a peek at the Orion Nebula or M15.

HAL Public Star Party 2021
 
 

You can also offer a (gentle) reality check in the comment sections of the social media posts that are overselling a celestial event. You can still be upbeat about the occurrence but let people know if certain equipment or experience is going to be needed. Inform them that that total solar eclipse this month is indeed an awesome sight to behold, but you’ll need to be in Antarctica to have a ringside seat.

Finally, if you are on social media, consider posting some of your images and experiences along with a few words about what went into achieving it. When you find a good article about getting started in amateur astronomy, share it. If you see someone starting off in the hobby, offer words of encouragement. You won’t be able to dispel every inflated claim made by astronomical B. T. Barnums, but if you establish your cred as a bona fide amateur astronomer, that person who is wondering if they might enjoy astronomy as a hobby will seek you out – and they will be in good hands.

Wednesday, November 24, 2021

Partial Beauty

Normally a partial eclipse, be it Lunar or Solar, is an interesting phenomenon that I'll observe and maybe snap a few photos - if it's convenient. Having seen my share over the years it's not something I am going to plan a PTO day for. It's pretty much a "yep, there's the hunk taken out of the Moon/Sun, right as it should be" event.

The partial Lunar eclipse last week was a bit of a different animal. First, it was darn near total at 99% - a circumstance that had not occurred in quite some time (the media was all over it heralding it as the longest partial eclipse in 500 years). Secondly, unlike a Solar eclipse where that 1% makes a huge difference in what you see, a Lunar eclipse so close to totality would likely be a fine sight. Prior Lunar eclipses have always begun to turn the Moon orangish before becoming totally immersed in the Earth's shadow, so certainly that should occur with this one.

Thursday evening started off overcast but with promises from the weather prognosticators that skies would clear after midnight. With calling out to work the next morning not an option I planned to do some simple naked eye viewing and perhaps try to grab a few shots with the camera. After the HAL meeting I got the Canon onto the tripod and set the alarm for about ten minutes prior to shadow maximum.


All too soon the phone began to chime and I arose to peek out the western bedroom window to see what we had. There it was, a dark red orb with bright edge at about 8 o'clock.

Faux "Diamond Ring"
What immediately leapt to mind was how we sort of had a Lunar eclipse version of the "Diamond Ring", the tiny part of lunar limb still bathed in sunlight acting like the emerging Sun at 3rd contact. HAL member Richard Orr did an excellent job of capturing the effect in his photo seen here. It was a beautiful and slightly eerie sight, resonating on an emotional level with ancient cultures who would be concerned about what was happening to the Moon.

Hyades, Pleiades, and Eclipsed Moon

While it was cold out it was no where near as bitter as the last Lunar eclipse (January 2019) under a "polar vortex". As my eyes adapted to the night I took a moment to appreciate the beautiful scene before me - a ruddy Moon beneath the Pleiades and adjacent to Hyades (the "V" asterism of Taurus). Framing the Moon on the camera's display at the lens' maximum focal length of 300mm I worked to get a focus. While there are a lot of pluses when using a digital camera rather than film, I hate the Buzz Lightyear nature of focusing where you can go to infinity and (just a tad) beyond. In the good old days you twisted the focus collar all the way to infinity and you were confident you had Moon and stars in sharp focus. And as fate would have it, my high power shots proved to be a tad soft once I saw them displayed on my laptop later that morning.

I went through a variety of lower focal lengths and exposures to record the surreal beauty of the coppery Moon gracing Taurus. After about half an hour I went back inside to warm up and nap a little before starting the day. My preparation and the eclipse itself might have been partial, but the enjoyment and beauty of it was total.

Pleiades and Partially Eclipsed Moon

Friday, October 22, 2021

64° N

Among the items on my bucket list is to see the northern lights, a fairly rare event from Maryland’s latitude. The last significant event around here was in the fall of 2001, but I was sadly unaware that it was happening. I still remember my disappointment the next morning when my boss exclaimed “Wow, did you see that sky last night!?”

With COVID vaccines making it reasonable to travel again I began thinking where my wife and I might go to perhaps witness the aurora. One logical approach was to investigate a tour with that objective such as those offered by Sky & Telescope. They were conducting a trip to Iceland in the fall of 2021 and the itinerary looked very nice – if you’re big into astronomy. My wife has a natural curiosity about the night sky but is hardly an aficionado of the heavens, so planning our own expedition where we could explore items of interest and possibly catch a northern lights display in the evening seemed ideal.

At 64° N in latitude the island nation of Iceland is certainly far north enough to regularly witness auroral displays. A little research also uncovered that October was not simply a random month selected by the official tour, but being near the equinox it has a better chance of seeing a display. It basically has to do with the favorable presentation of the magnetic field lines in interacting with the solar wind as discussed in the October 2021 issue of S&T.

We arrived quite early on the morning of October 4th and were greeted by a taste of Icelandic weather – a very blustery, rainy, and cold dawn, quite a rude change from our departure the prior evening with temps in mid-seventies. We made our way to the Northern Lights Inn where we would be staying for the week and grabbed a quick nap. That afternoon we explored the capital city of Reykjavik, roughly 25 miles away.

That first evening the skies were partly cloudy with roughly 50% of the sky being obscured at any one time. The wind in Iceland is seemingly perpetual and vigorous, so it was not exactly pleasant to step outside for any length of time. Being some 24 degrees more northerly in latitude I was immediately struck by the height of the Big Dipper which was near its anti-culmination point due north. From Towson it is so low to the horizon I lose sight of it, but here it was skimming above the rooftop with ease. Polaris had ascended noticeably higher and, while it was only midnight, Jupiter was already drawing close to the horizon in the southeast. I had anticipated in this little coastal town of Grindavik that the skies would be quite dark, and while the Milky Way was plainly visible it was not nearly as robust as I was expecting. I scanned the northern skies for any signs of the ethereal emerald glow without success, so I turned in with hopes that we’d get an aurora wake-up call from the inn keeper.

The next day we toured the "Golden Circle" and visited some spectacular scenery. Þingvellir National Park showcases the mid-Atlantic rift where the American and European plates meet (one of the few places where it lies above sea level). There was also the majestic Gullfoss water falls - we only wish we had more time to linger there.

On the ride back to the inn I was checking weather and aurora potential for the evening. The skies were predicted to be partly cloudy with (as usual) brisk winds, the KP index was around 3, a slight potential for auroral activity. A little before midnight I went out with camera in hand in search of Northern lights. It was mostly clear with the light dome from Reykjavik visible in the northeast. While scanning the skies I also decided to take some 20 second constellation shots, which was challenging because of the wind buffeting the camera on its tripod. After about 30 minutes I decided to go inside and hope for an aurora wake-up call (which never came).

The next day I was reviewing the constellation shots when I was startled to see the characteristic green glow beneath the Big Dipper. It turns out that while I wasn't successful visually capturing the Northern lights I had managed to record it photographically. Retrospectively, it obviously makes sense that over a 20 second interval the CMOS chip could record the glow when it was too faint for my eyes.

 

The Northern Lights under Ursa Major

The remaining 2 evenings in Iceland were overcast so there was no additional opportunity to catch the lights. And, of course, the following week I saw reports of some fantastic aurora lighting up Icelandic skies - timing is everything. Our trip was truly memorable - surreal and beautiful nature, superb seafood, and welcoming people. I guess I'll put an asterisk next to that bucket list item of seeing the Aurora Borealis in that while I did not see them, I did manage to photograph them. 😊