Special Occasions

The science writers are at it again, hawking the "Grand Conjunction" of Saturn and Jupiter that will take place on December 21, 2020 as a bright Christmas Star for all to see. On that evening the two planets will be a scant 0.1° apart, close enough that they should both comfortably fit into most amateur telescopes at low to medium power. It is clearly a special occasion since the last time these two giants were visible this close together in the night sky was 1226 when St. Francis of Assisi was around. Of course there's also the fringe media that is having a ball with it, claiming this alignment at Winter solstice is a bad omen (just search for "grand conjunction 2020 predictions").

Hype aside, amateur astronomers are indeed excited to witness this alignment. Roughly every twenty years Jupiter catches up with Saturn, pairing up with it in the heavens. In 1980 and 2000 they got to within about 1¼° of each other, and will do so again in 2040. But the 2000 and 2040 alignments suffer from Sun glare, making the spectacle hard or impossible to appreciate. The spring of 2060 should deliver a mega hit to any conjunction junkie with Jupiter and Saturn getting within about 1 degree of each other amid Taurus while Venus threads her way through the Pleiades and a crescent Moon thrown in for good measure on the night of April 4th!

Grand Conjunction of 2060

So, looking at that Stellarium Online image of the conjunction on the night of April 4th in 2060, did you get excited? Did you think, "Wow, don't want to miss that!" (assuming you're under 40)? What is it about these gatherings of celestial orbs that makes the amateur astronomer circle the date on their calendar in expectation?

I think some of it relates to the yin-yang aspect of our hobby. On the one side we have the "passive" sense of the heavens. They are consistent, steady, predictable. There is something almost reassuring seeing Orion raise up from his side on a late October evening. We know that almost nothing of shallow or deep space has altered much since Galileo's first scope or Messier's compilation of faux comets. When I say "Albireo" your mind's eye brings forth a beautiful double star. Like travelers who've embarked on a country wide road trip to see the sights, we revel in comparing notes and swapping photos of the cool things we've visited. 

And then there's the "active" side of the night sky. Here we seek to catch ephemeral sights that may be constrained by location or good fortune. You venture out under cold, clear December skies on the 12th in hopes of catching a Geminid that is spectacular. We trek across country or even across continents in hopes of catching a few minutes of the solar corona. These two examples categorize the action; some of it is somewhat random (meteor showers, super novae, sunspots, aurora) while others are anticipated. 

Most of that predictable action centers around alignments. Conjunctions, eclipses, occultations, transits - all provide opportunities to experience something that ranges from uncommon to very rare. And while we have the sublime beauty of Saturn's rings or wispy tendril's of Orion's sword available to us on any clear night when they lie above the horizon, the beauty of a celestial alignment is often brief and may not be repeated in your lifetime. I doubt I shall ever see another Mercury transit but hope to work in another total eclipse.

Thankfully the universe is like a top chef at a 5 star restaurant, continually serving up one delightful alignment dish after another. In spring we had the octennial passage of Venus through the Pleiades, in fall we had a generational opposition of Mars. And now we get something even more uncommon, a "grand conjunction" of Jupiter and Saturn to close out a rather tedious year. So go out there and try to see it, photograph it, soak it in as yet another special occasion brought to you courtesy of the universe!

Jupiter & Saturn Drawing Together on Dec 8, 2020

Celestial Oenology

It's the holiday season and, like every year, thousands of people will be convinced that they want to take up astronomy as a hobby. Even before Thanksgiving this year I've had two people reach out to me for advice on what telescope they should buy for a loved one (or perhaps in truth the scope is for themselves as well as the loved one). Facebook teems with posts asking the same question. Unfortunately there is no easy answer to the question of "what's the best starter telescope?" because it is a nuanced question with a variety considerations. 

Suppose that instead of exploring the universe you were taken by the idea of exploring the world of wines. Perhaps you had a friend who introduced you to a couple of nice wines at a dinner party. They skillfully chose the wine and paired it with some good food to create a delightful experience.

The Party Introduction

Or maybe it is those posts on social media or articles in a magazine you thumbed through in the doctor's waiting room. They tease at this world of tasting & enjoying wine that convinces you that you want to explore this hobby. 

Whatever the trigger, you are sure this is worth pursuing and you want to purchase a corkscrew to enable you to enter this realm. But which one is best? An inexpensive and rudimentary one may only be good if your are skillful enough to wield it. An expensive one with bells and whistles may work for any bottle but likely requires you to read the manual thoroughly to use it properly, spending as much time opening the bottle as consuming it. A simple but efficient opener should allow you to master its use quickly and serve to open many bottles of wine.

With your new tool to open the oenophilic world your next step is to target some wines, so off to the liquor store. The array of choices can lead to analysis paralysis. Red or white? Fruity or dry? Each category of wine seems to have its own characteristics and proponents. You might ask your friends who already enjoy wine what their favorites are and try sampling some for yourself. Or perhaps you follow the recommendations in a magazine or good book to start you on your exploration. As you sample the varieties you find you're drawn to some more than others and become passionate about locating ever more examples of your favorite. You also might find that keeping a log with notes about the wines you've tried helps improve your appreciation of them.

After some time you become aware of accessories that can possibly deepen your enjoyment of your favorite varieties. You open up your wallet and start to add to your armamentarium of wine tools. Some prove to be useful for any bottle you select, while others have more specialized application. 

So let's distill what our theoretical journey into Oenology can offer the budding amateur astronomer:

1.  When picking a telescope you should probably avoid inexpensive models that will frustrate you and likewise expensive models that will likely baffle you. Somewhere between $300 to $1000 should net you a quality starter telescope that can give years of pleasure, even after you upgrade.
   
   
2. Figuring out what to view is challenging so consider asking other amateurs what they enjoy, or pick up a copy of a book that is geared towards initial exploring of the universe. Just like wine is an "acquired taste" with many glasses needed before you can discern those subtle flavors of a vintage, examining faint fuzzies or planetary features is an acquired skill. The more you observe them and read about them the more subtle details you'll uncover and savor.
   
   
3. Just as your wallet will dictate whether you can afford to taste the more subtle and exotic wines, your budget will also influence your ability to experience the heavens. If you are smitten by seeing features of Jupiter and Mars then sharp optics, tracking mount, and a video camera are in order. If you yearn to see the spiral arms in M51 then a large Dobsonian will fill the bill. But they will mean a financial commitment.
   
   
4. Just as oenophiles gather at wine tastings to share sips and opinions, amateur astronomers benefit greatly from joining a club and getting out under the stars together where they can share views.
   
   
5. Accessories can make your hobby more enjoyable and enhance what you taste/see. Do your research before making a purchase by reading reviews online or checking with club members who already use the item, but gadgets are part of the fun.

Go ahead and take the plunge into the world of amateur astronomy - it can provide you years of enjoyment and new friends that share your enthusiasm.

Mars Pays a Visit

Every two years & two months we are treated to a celestial show as Mars comes calling for a visit. For most of that 26 month interval the size of our brother planet is diminutive - under 5 arcseconds for nearly a year of that time, hovering around Uranus' size (3.8") for nearly 6 months.And as many amateur observers know, not all alignments are equal. Because of Mars' fairly elliptical orbit, the meetup can happen when Mars is at its farthest point from the Sun (aphelion) or when it's near its perihelion (or somewhere in between, obviously!). The difference is significant in terms of how large the disk will appear in the eyepiece (chart below). So perihelic oppositions are almost generational events, taking place every 15-17 years and boasting nearly twice the size of an unfavorable aphelic approach. It's little wonder that the excitement and anticipation for Mars fans has been growing all summer. Heck, I've even seen a lot more interest from the neighbors out for an evening stroll who know that Mars is "up there somewhere". It's a shame that Covid keeps me from sharing more than the image on my computer screen, and my hopes for a fun Halloween activity for the kids is gone as well.

Mars Size Over 2 Year Period

Range of Opposition Sizes

This apparition culminated in a closest approach on the night of October 6th, and opposition almost a week later on October 13th. That may seem odd at first - after all, all the other outer planets have their closest approach synced up with their opposition date. But for Mars we need to factor in its faster orbital rate compared to the gas & ice giants along with its orbit eccentricity. By October Mars was already past its perihelion point of its orbit, so that means with each passing day it draws farther from Earth. So it stands to reason we hit closest approach as a sweet spot a little before opposition since the two planets are pulling away from one another. So here's a pop quiz. The 2018 opposition took place before Mars' perihelion. Would the closest approach happen a few days before or after that opposition?

As if the orbital machinations aren't enough to make a good view of Mars elusive we need to add a wild card into the equation - dust storms. Planet-wide, rover-killing dust storms are not uncommon as the Martian atmosphere warms. And of course, warming is going to be at its most pronounced during the planet's perihelion. The much anticipated perihelic opposition of 2018 fell victim to an impressive global storm that hid features from our prying eyes and instruments for weeks.

But here's the good news - so far this opposition has been relatively free of dust storms, and at over 22" in size the views have been great! I had hoped to have my 10" reflector back in commission in time for the event but that did not pan out. My old reliable 6" RV-6 classic Newtonian has come through, however. On closest approach night using a light red filter (Wr23A) and an 8mm TMB planetary eyepiece (150x) I could see the wedge shaped Syrtis Major/Mare Tyrrhenum feature on the central meridian. A little pearl sat atop the south pole, the receding ice cap as summer has just occurred a few weeks ago for Mars' southern hemisphere. On the setting limb a distinct peninsula albedo feature, Mare Cimmerium, was easy to pick out. One thing I found quite interesting was the rather subdued appearance of Hellas which lies between Syrtis Major and the polar cap. Normally Hellas is quite a bright feature, but this time around it is muted for some reason. You could almost envision the combination of albedo markings looking like a steer head silhouette.

A few nights later near opposition evening I was able to get out and observe a slightly different portion of the Red Planet's globe with the same equipment. Here Syrtis Major was not visible, getting ready to rise on the limb. But Mare Cimmerium was in full view as well as dusky regions south of it where Mare Chronium also appears to be a little darker than I would have expected. And even though it's only been a week, I struggled this night to pick out the polar cap.

I also achieved a life-long desire to image Mars successfully. Two years ago my attempts were undermined by the dust storms and still learning the ropes a bit, acquiring better software and tools over the interval. My most recent addition has been a Baader UV-IR cut filter which serves to enhance images obtained with a color video camera. Playing with PIPP and Autostakkert!3 have also allowed me to tease out as much detail as I can. While I'm no where near the level of the incredible images I see in my role as ALPO AAC (posting images to the gallery), I feel pretty pleased with what I can produce with a smaller instrument and a setup far less costly than the leaders in amateur planetary photography. And after all, it's more about learning and improving, arriving at something that brings you joy and a sense of accomplishment. 

So, if you are an amateur astronomer I urge you to give this a go - Mars won't be this good again for 15 years. You don't need a big scope - I have caught albedo features and the polar cap using my 80mm Vixen earlier this summer (Of course by the time you read this the polar cap will likely be dissipated). If you are new to planetary observing then be sure to take your time at the eyepiece. At first you may not make out anything, but keep looking, waiting for those moments of atmospheric stability where you'll grab a quarter of a second of good seeing and pick out a dark marking. As your eye and brain work together you'll end up "integrating" those moments of clarity to fashion an image in your mind of what the planet looks like. Be sure to use a relatively high magnification, perhaps 30-50x your aperture in inches. Hopefully you have tracking ability so that you can relax while viewing the ocher orb, but even if you have to play bump & observe with your Dob, it's still worth it! I'd also suggest a rough sketch of what you are seeing as you observe, it not only gives you a memento for later but will improve your observing skill.

Mars with Pastel & Charcoal

Finally, even with just your naked eye, go out and admire that brilliant orangish beacon rising in the east. Drink in the setting, the place from which you are seeing it, the terrestrial scenery and sounds that accompany Ares as he rises amid the stars of Pisces. Let your mind ponder that at this moment we have rovers on its surface and orbiters whizzing above it, beaming back amazing images of this world. Take comfort in the rhythm and predictability of the heavens, especially now. And perhaps dream that, just maybe, the next time Mars gleams this bright you'll be able to say that humans have set foot on the Red Planet!

Doorstep Mars

Answer to pop quiz: Opposition was July 27 and closest approach happened 4 days later on July 31

NEOWISE Breaks the Drought

“Comets are like cats: they have tails, and they do precisely what they want.” ― David H. Levy

While they are not as infrequent as Venus transits, a showy comet is pretty rare based on my experience. And hands down they are the biggest tease that the solar system has to offer. From Kohoutek (1974) to this year's PANSTARRS (C/2020 K1) comets often show promise of putting on a show only to either massively under perform or occasionally just crumble into pieces. Even the most famous of comets, Halley, was a bit of a dud for northern hemisphere observers on its last visit in 1986.

In my half century of sky gazing I've seen 3 comets that fit the archetype of a comet: Bennett (1970), Hyakutake (1996), and the grand Hale-Bopp (1997). There are likely some I missed when I was less active but most comets that I've viewed are small fuzzies that need a scope or binoculars to see well and resemble a Manx rather than a Persian feline. They make you appreciate why Messier, fooled by the faux comets of nebulae and galaxies, started his catalog.

I had adopted a "I'll believe it when I see it" attitude towards NEOWISE C/2020 F3 when the initial assessments were that it could be a winner. No Lucy, this Charlie Brown wants to know that football isn't going to be pulled away at the last moment! And by the way - I know we need these robotic scopes to efficiently catch incoming asteroids and comets for our safety, but their comet names are so sterile. And it takes away one of the best lotteries in amateur astronomy - the glory of finding a great comet and having your name slapped on it. If I were in charge I'd say that the robots have to keep quiet - report their finding to a secret database but then wait for some lucky amateur to stumble upon it and get the naming honor. Bring back awesome comet names like Ikeya-Seki! Sigh - but I digress...

Once NEOWISE had completed its rendezvous with the Sun the reports - and images - started coming in with good news. There appeared to be a naked-eye visible tail, even from suburban venues. Excited with the prospect of ending the long drought of a fine comet I waited for a break in the normal Baltimore July weather pattern - hazy, warm, humid. Finally the weather sites agreed that Sunday morning was likely to be a good opportunity. While many HAL members were planning to assemble at Carrs Mills I opted for a closer spot with good horizons at Dulaney Springs park. 

I pulled into the parking lot with camera, binoculars, and face mask (just in case) at about 4:15. A last quarter Moon hung high above, and Venus gleamed adjacent to Aldebaran. To the left was Capella, and farther to the left should be roughly where NEOWISE ought to be hanging out. I thought with averted vision I could catch a shaft of light extending above the tree line, and the binoculars confirmed it. Moving out onto the field to shift the comet's apparent position into a break in the trees revealed a glowing nucleus and nearly 2° tail.

NEOWISE's Tail Above Treeline

Setting up the camera I worked on getting some shots of NEOWISE as it ascended above the treeline. As I'm taking one of the shots I notice a bright object moving nearby. First impression was that it was the ISS starting a pass but then it winked out, pretty suddenly. Odd - did it just enter the Earth's shadow that quickly? Something didn't seem quite right so I noted the time in order to check later as to what was in the area. As it turned out Jim Johnson captured it and properly identified it as a meteor. It was likely quite distant given the appearance in both our shots is pretty similar while separated by some 25 miles.

NEOWISE Crests Treeline and Greets Meteor

As NEOWISE gained altitude it became a fine sight! To the naked eye it had perhaps a 1^st magnitude coma gradually fading into a delicate gossamer tail. In the 7x50 binoculars the head was a compact, bright white with the tail streaming upward like a jet contrail. The tail had more yellowish-gold tones compared to the whiter coma, making a beautiful impression. The tail also seemed to be a bit stronger on its edges, as though the coma had active jets on each side. I drank in the experience of this celestial visitor to our neighborhood, knowing that the creeping dawn would soon overwhelm its presence. By 5 a.m. I headed back home, eager to see my digital images on a laptop screen.

A Sight to Behold

So now NEOWISE heads back out to the icy depths of the solar system and we'll get to see it in a more convenient evening sky. Hopefully it will continue to delight as it gradually recedes from view over the summer months.

The Venus Show

One thing is for certain - the disruption of our routines thanks to the COVID-19 virus outbreak has created a vacuum. Binge-watching has taken center stage for a lot of America, but if you step outside you'll find another show streaming through the evening twilight. Venus has been dazzling, high above the horizon like a super intense LED. Even the average person out for their stroll around the neighborhood notices this gem in the western sky.

Our sister planet returned to the evening twilight last fall. I recall catching sight of her in early November heading south on I-81 in Virginia on our way to NC, anchoring a wonderful Zodiacal alignment of Venus-Jupiter-Saturn. Slowly but steadily since then, like a diver ascending the ladder to the high dive platform, Venus has been gaining altitude from the Sun's glare.

Venus and crescent Moon Thanksgiving evening 2019

This evening apparition has been particularly auspicious, hitting a trifecta + one of favorable celestial mechanics. First, for us spring brings the angle of the ecliptic - that imaginary highway that the visible planets traverse - to its steepest angle with the horizon, reaching 73° on March 24th. This means that every degree that a planet lies from the Sun translates to maximum distance above our northern hemisphere horizon.

Next, that date of steepest ecliptic coincided with Venus reaching the point in its orbit where it forms a right angle alignment between itself, the Sun, and us - i.e., the greatest distance it can appear separated from our home star. The result of all this? Our brilliant neighbor began the evenings in late March a full 44° above the horizon, an inner-planet party animal that stayed up until close to midnight.

Another favorable aspect is that on March 20th the planet was at perihelion - the point in its orbit where it lies closest to the Sun. This contributes slightly to the planet's brightness so that when it hits that sweet spot between disk size and phase on April 28th it achieves an eye-catching maximum brilliance of -4.4 magnitude. While it may not be visually apparent that Venus is reaching an incremental notch above its normal brilliance it is as good as it gets (but don't tell the press less we start a "Super Venus!" meme). 

Perhaps the pièce de résistance of this apparition was Venus making a call upon the Pleiades, passing through their midst on April 3rd. While not rare (it happens every 8 years due to celestial mechanics returning Venus to roughly the same spot) it is one of the most lovely and photogenic conjunctions around. I have (somewhere) a shot of a similar alignment some 24 years ago taken on film. This time around I used the digital magic of taking 200+ shots with my 200mm lens and stacking them to produce a nice souvenir of the occasion (star spikes courtesy of Photoshop).

M45 and Venus on Apr 2, 2020

 

But wait - there's more! Like that diver perched high above on the platform our sister planet is preparing to swan dive into the glare of the Sun. Once we reach dichotomy (half phase) Venus becomes a more interesting target for amateur astronomers with even a modest scope. We enter a period where the size and apparent phase alter week by week and then day by day as we approach the June 3rd inferior conjunction date. If you have never tried to spot Venus in the daytime you'll have a great opportunity on April 26th using the Moon as your guide as it slides roughly 5° south of the planet. It also is a great time to see how soon you can pick out the phase using only binoculars or capture it using only your telephoto lens.

Remember, you don't have to practice social distancing with your old friends in the night sky - let them infect you with their beauty and mystery!

Improv at the Impromptu

Last Saturday was blessed with a dome of high pressure over the mid-Atlantic, bringing transparent but frigid skies. Despite the chill Chris Miskiewicz announced he'd open Alpha Ridge for a HAL Impromptu star party. As soon as he called it I fired up Telescopius and elected galaxy NGC 2841in UMa as my primary target for a photography session. If I could hold out against the cold I'd also attempt a wide field of Messier duo of M97\M108. Little did I know that despite my best efforts of being prepared for my evening under the stars I'd need to circumvent a variety of unexpected challenges!

I started packing up the equipment into the Rogue about 5pm. First in was the Orion Atlas EQ mount - but wait! What the heck!? One of the tripod leg tips was missing! I spent 10 minutes scouring the area where I usually observe from home and in the garage where the tripod is stored but no luck. I decided that I could still make it work for the evening by extending the affected leg a bit. Improvisation #1.

Made it to Alpha Ridge as twilight was fading fast and the temps dropping. I transferred the equipment to my observing spot and roughly aligned the mount on the North Star. Turning on laptop and the PoleMaster camera I thought I had Polaris in the field, but soon realized it was an imposter. Nudging and bumping the mount this way and that brought no other suitable candidate star onto the screen, so finally I resorted to taking the camera off and sighting it through the shaft as was my custom prior to PoleMaster. This improvisation allowed me to get Polaris onto the screen when I reattached the camera - all at a cost of time. Finally, about an hour after my arrival I was ready to target NCG 2841 and begin taking my series of 30 second exposures.

I popped on the Telrad and reached for its On lever, only to find it was already on. Nooo! I cranked up the rheostat in hopes that maybe it had happened when loading the Telrad into the car but the poor batteries had no juice left to give me. Sigh - and no spare batteries with me. Alright then - we'll do it using the Vixen scope's finder. Improvisation #3.

I get the Tiger Eye galaxy in the eyepiece and begin to attach the Canon and establish its WiFi to my tablet. Boom - my Orion red headlamp I'm wearing shuts off. Did I bump it? No, apparently I'm having the worst dead battery night I've ever had. Fortunately for this bump in the road I did at least have a hand held red-light flashlight that I dig out from my observing toolbox. With improvisation #4 I'm finally connected and snapping photos.

Sketch NGC 2814

The allure of these clear February skies keep me from being bored while firing off round after round of 30 second exposure. I drink in the showy winter constellations: Orion and his dogs, the Twins, the Bull - all old friends who have crested and are riding the night tide to the western horizon. Over the dome of HALO the Big Dipper stands on its handle as if to vault itself high overhead. Leo climbs his way up the eastern sky as the subtle Hydra crawls beneath his feet. No matter how high-tech the gadgets become and what they can do, there is still something in the amateur astronomer's very being that finds joy in taking in a starry sky with nothing more than one's eyes.

By 9:15 p.m. the cold is beginning to win - I clearly do not have the perseverance to start a new session targeting the Owl Nebula and nearby galactic neighbor M108 - that will need to wait for another spring evening. I take my final 30 second light shot and go to get my home-made "light box" that I use to take my flats. Arrghh - are you kidding me!? I guess with the distraction of finding my peg-legged tripod I neglected to pack it. Think, think, think - how can I get a diffuse light source for these flats? I wonder if - maybe I can find a way to make my Samsung 10" tablet display an almost completely white screen? Can I find some web site or document to meet my need? A quick Bing search and - by Jove - there it is! The "White Screen Page" is exactly what I need for Improvisation #5. I load the page on my tablet and hold the tablet over the Vixen 80sf dew cap and rattle off my flat shots. Wow, that improvisation worked great!

Before I pack it in I take a few minutes to do a visual observation. At 60x in the 80mm refractor the galaxy is readily seen as a soft, elliptical glow running more or less in a N-S orientation. There's no core visible but the star field is pleasant with a tight, white double at the southern edge of the field competing for one's attention - the sort of pair whose symmetry of magnitude and coloration make it stand out. There'd be no hope of seeing the subtle light of this distant island universe from my driveway, so I linger a few moments to enjoy the benefit of Alpha Ridge's skies.

The next day I do some preliminary work with the image files in DSS and PixInsight. It's always a bit like Christmas morning when you open up that stacked photo to see what you have. The result is decent for a first pass but I think that there's more in there that can be teased out - if only I knew the intricacies of PixInsight better. The good news is that with the data in hand and safely dropped onto the cloud storage, NGC 2841 can await a cloudy night in the future to have its details extracted from the hour's worth of exposures. 

NGC 2841, the "Tiger's Eye" galaxy

Oh - and that eye-catching double? Turns out that's STF (Struve) 1341, a near equal 9th magnitude pair with a separation of 20" and sun-like spectral class G5. And to top it off, the preceding one of this E-W aligned pair [HD 80606] actually has an exoplanet associated with it weighing in at about 4 Jovian masses and whipping about the star once every 111 days. 80606b also sports an amazing orbital eccentricity of e=0.927 - check out the diagram below from NASA website "Earth Observatory" to get a sense of how elongated the orbit is (Pluto is e=0.25 for comparison). As Spock would say, "Fascinating..."

Orbital Eccentricity

Transit Terminus

This past Veterans Day the tiny planet Mercury was scheduled to cross the face of the Sun in an event visible in its entirety from my vantage point in North America. Such alignments are infrequent yet not as rare as those when we get to see Venus interposed between us and the Sun; we get two of those within a decade and then the interlude is over a century before the next transit pair. For Mercury we get to witness roughly 13 such events in a century. Like any celestial phenomena that takes place in under 12 hours, not every point on the globe gets to see the transit - in some locales the entire event happens while the Sun is below the horizon (a.k.a. night time).

I've been fortunate enough to catch a couple of prior Mercury transits. My first was on Saturday May 9, 1970, just about two months following the amazing total Solar Eclipse for the east coast that took place on March 7th. My notes have long since been lost on that event but I do recall seeing the tiny dot of our smallest planet against the Sun using my RV-6 Newtonian using a solar filter by the same company. The next transit that I have a clear memory of (and some notes) was Monday May 9, 2016. It's not just coincidence that both are on May 9th - the orbital mechanics dictates that a transit of Mercury can only occur within a couple days of May 8th or November 10th when Mercury's orbit intersects Earth's plane. If Mercury happens to be undergoing inferior conjunction at that time we have ourselves a transit.

Looking at the predictions for Mercury transits beyond 2019 showed that while there was one set for 2032 and another in 2039 neither would be visible from my side of the planet. That makes the next candidate May 7, 2049 - putting me well into my nineties. So for me the reality was that the November 11th event would be my swan song for any planetary transits. In a year that brought several reminders of my own mortality here was the universe offering yet another commentary upon it.

I decided to try to make this last Mercury transit the best yet. The prediction for 1st contact was 7:35 a.m., which meant the Sun would be quite low in the sky. If I could find a suitable location I might be able to witness that 1st contact and maybe even the "black teardrop" effect. But a more realistic goal was to try to obtain some nice photographic captures of the tiny orb as it marched its way across old Sol. I planned to take the RV-6 on the Atlas mount with me and the Canon Rebel t6s camera and the DFK21AU042 planetary video camera. I gathered everything together the evening before and then fashioned a solar filter using some Baader solar film, sandwiching it between stiff cardboard. The weather forecast was iffy - most prognostications had high clouds moving in as the morning wore on. I set out the equipment so that when I got up it would be easier to load it into the Rogue and set off in search of a venue with good eastern horizon.

The pre-dawn was not encouraging. While portions of the sky were clear the eastern direction had a buildup of high altitude clouds - the Sun was clearly not going to penetrate it. Regardless I set off looking for a location. I toyed with the idea of heading to the parking lot at Leidos where I work. It would be pretty empty on Veterans Day (a government holiday) and the horizon is pretty good. But the commute could be 30 minutes or more meaning the transit would likely be underway by the time I made my own transit and got set up. In the end I set up on the western edge of the ball field by the BYKOTA senior center in Towson, trying to position myself to catch the Sun soon after it rose. I had used the spot before in 2004 to catch the Venus transit soon after sunrise.

Setup outside BYKOTA, waiting for clouds to disperse

The 1st and 2nd contacts came and went without my witnessing them, a combination of clouds and obstructing building. Finally by about 8 a.m. the clouds thinned just enough that I could target the Sun using the shadow technique. I popped in the 16mm Plossl and focused. It took a moment but then there it was - a tiny black silhouette of planet Mercury against a solar disk completely devoid of sunspots. Yay! I could at least say I had successfully witnessed my third transit of Mercury!

Fighting clouds & buildings at the start

My initial attempt to record the phenomena was with the DFK21AU042 video imager, but it proved a frustration. With the Sun over my shoulder making it hard to see the screen and focus at the same time I was not getting any worthwhile results. I switched to the 35mm camera adapter for eyepiece projection using the 16mm and the camera's live view mode,  working to bring the solar limb into sharp focus. Even though I finally got to what seemed to be a good sharpness it was challenging to see if the view contained the tiny dot of planet Mercury. Without any sunspots that could serve as landmarks to guide me to position the best I could do was approximate, My approach evolved into taking a shot, bringing it up for review and enlarging it on the tablet to see if I by chance had caught the messenger planet. If not I used the RA/Dec control pad to slew to another part of the Sun to take another shot. It took a little while but finally ended up with a pretty decent image of the transit.

Mercury Transit - ISO 400 at 1/15 sec using 6" f/8 with 16mm Plossl

As I worked to get some photos there was a gradual stream of dog walkers, joggers, and curious neighbors wondering what the heck was going on. I obliged most of them with a peek through the scope so that they could tell friends and family they had seen it. By a little before 9 a.m. I decided to pack up and head home to finish observing and capturing the transit. I was back in business on the driveway of 404 within about a half hour, setting up the Vixen 80mm as well so that I could take some whole disk shots of the Sun sporting Mercury. The clouds continued to threaten - in the short video below you can see them crossing the face of the Sun. There were a few times when the clouds won but surprisingly the bulk of the transit window the Sun was visible.

Around 10:30 a.m. I decided to start taking a set of bracketed shots of the whole disk every 15 minutes in the hopes of creating a final product that would document the tiny speck making its way towards 3rd contact. I got most of the shots but the 10:45 one was a bit out of focus. It was quite challenging to get a sharp focus on the Samsung tablet that was connected to the Canon due to the Sun making it hard to see the screen. I resorted to having a pillow case draped over my head every 15 minutes as I tried to recenter the Sun and check the focus.

Mercury marches across the Sun on Nov. 11, 2019 (times EST)

As we slid past noon the tablet was running low on battery, signaling that photography would soon be over. I took a few more looks at the tiny, silhouetted dot to appreciate the scale of things in our solar system. As the clouds began to thicken yet again I decided to conclude observations and began to breakdown the setup. I may have missed the ingress and egress but overall it was a fine and memorable event to mark my last planetary transit!