Spectacular Atlas V Rocket Stage Deorbit Burn Over Beaghmore! - September 27th 2021

This was one of those examples when I became focused on one thing then suddenly something completely unexpected happened which suddenly made it into my most memorable sky events category and a rarity I may not witness again for a very long time, if ever. Man made spectacles were the last thing on my mind on September 27th however my eyes were watching the skies for two reasons. The first was a risk of thunderstorms and the second was the prospect of a bright aurora display. To cut a long story short I focused on the convective potential first and ended up at the Co. Antrim coast in the hunt for early Autumn cells, it was the time of year when solar heating inland is ebbing away every day while sea surface temperatures increase, when this transition occurs one can except to see an increase in ocean thunderstorms, especially when cold unstable air interacts with warm moisture-rich ocean vapor, today was one of those days. Convection did form, I observed low topped towering cumulus and mammatus however the tops never seemed to get high enough and the anvils were skinny and fuzzy, I knew from the visual appearance that they were not going to produce so by 14.00 I decided to call it a day and headed home for some rest, I was also craving Roisin's home made vegetable soup.

Plan B was to warm up then head out aurora hunting, a CME was expected to hit with NOAA forecasting G2 storms and with clear skies it looked like a good plan. However as darkness fell the geomagnetic set-up wasn't happening, solar wind speeds remained low and the Bz was north, there would be no auroras. Normally that would be enough to end any night drive into the middle of nowhere however something was telling me that I should head out with the camera anyway and do some night shooting, I actually had no idea what I was going to shoot but fancied a time lapse or star trail in the local area, just being under the stars again was appealing as I felt a strong urge to reconnect with the sky.

I just happened to be scrolling through twitter when suddenly I spotted a curious post by Astronomer and science writer Will Gater who posted...

''Heads-up UK skywatchers: potential for an interesting sighting of a rocket stage deorbit burn in the coming hours''

Will had shared a post by Marco Langbroek with the following details...

''Now Landsat-9 has cleared the launch tower on time, a reminder for NW Europe that later tonight, the Centaur upper stage deorbit burn might be visible from the UK, Netherlands, Belgium, France, Ireland, Germany, Denmark''.

This really got my attention and soon more info appeared, it would be visible at 22.10 BST with the map above being the only visual information available. This was very short notice and by the time I read it I had perhaps 1.5 hours to come up with a plan. There were no sky charts published and there was no time to wait about for someone to make one, at least I had an approximate time however where in the sky would it appear?, going by the map it looked like the east was the best bet however I knew I would have to be switched on incase I was wrong.

I wrapped up warm then drove out into the night, my main intention now was to observe and capture this rocket burn, I could have stayed in the backyard however lights and horizon obstructions would spoil the photo potential so I decided to get out into the countryside to find truly dark skies and do things properly. I decided on Beaghmore where the skies are dark, I pulled into the picnic area before the stone circles and did my watch from there. I was 50 minutes early however this was intentional, I wanted to get my gear ready and eyes dark adapted and tune into the night sky. Showers had just passed through and the clouds began to clear to reveal a beautiful dark starry sky.

I honestly didn't know what to expect with this burn up as I had never witnessed such a thing before, truthfully my expectations were extremely low. I have observed the ISS countless times as well as many space shuttle passes, space chases, Mir space station and supply craft over the years but never anything of this caliber. All these events looked like bright stars so this was the lower threshold of what I expected to see. However, secretly I was being cautiously optimistic, for I had seen rocket events captured on camera before from different parts of the world and some of them looked absolutely amazing taking the form of striking comet-like forms among the stars. I have always wanted to experience an event like those however such transient apparitions rarely happen near Ireland, I have never seen such a dramatic deburn before since I first began sky watching before 1997.

Just in case this turned out better than expected I set up two cameras, the Canon 5D Mark IV on one tripod and Canon 600D on another tripod. I had a 15mm wide angle on the full frame and a 50mm F/1.8 on the crop sensor, I suspected I might need a little magnification in case this turned out to be impressive so the 50mm was a good option. I then took test exposures of the sky, checked focus then left the cameras alone and began tuning into the sky. I still had 30 min's to pass the time so I gave the sky a good visual check, known as a dome search, checking the familiar constellations in case a Nova had erupted then I studied sections of the Milky Way and spotted M13 and M31 with the naked eye and my old friend RCrB just below 6th magnitude. As the minutes ticked by I began to get a little anxious, I honestly didn't know what to expect, would this just be a moving star or something else entirely?, will it be low near the horizon or high in the sky? and would it be bright or faint?, it could even be a non-event. One thing was for sure, if and when I did see it I would need to get one or both cameras shooting fast.

With the exception of a few passing cars along the country road the countryside was dark and quiet, the wind had fallen light and an eerie calmness was palpable. I suspected the burn up would happen in the east but if I was wrong I could miss it so I was constantly checking all sky sectors in a constant loop while periodically glancing to the north for any tell tale signs of aurora activity, during this process I began to drift off into a world of my own, a semi trance. Suddenly my instincts sharply kicked in and I felt an urge to look up, nothing yet, then I did turned around to the north east and looked behind me and there it was, or should I say there they where, I yelled out loud ''holy s**t!!!'', among the stars, where moments before was nothing, now there was a spectacular apparition moving among the stars like twin torch beams, I was so shocked by the spectacle that I momentarily froze not knowing what to do, all I heard was a voice in my head saying ''shoot shoot shoot'', I fumbled for a camera in the dark, suddenly having two cameras was confusing, deciding on which to use slowed me down further, but during a quick evaluation I realized I needed the 50mm to get me in close to do this remarkable moment justice.

Thank goodness I had been prepared and the camera was already pre-focused with cable release and night settings selected with lens cap removed, this saved me priceless seconds. The naked eye view brought me back to my first sighting of Hale-Bopp when I knew I was seeing something special and alien in the sky, something which normally shouldn't be there, any logic and scientific understand was gone and pure raw emotion took over, this felt like mythology, to me these looked like bright Banshees moving among the stars, and moving they were, the motion was fast which got my adrenaline surging even more as I knew I wouldn't have long to get images before they were gone, I panned the DSLR to the left, panned upward, saw them blazing through the viewfinder then took my first exposure.

I was using a 50mm F/1.8 prime lens on a crop sensor camera stopped down to F/2, ISO1600 for 3 seconds, this crop shows the motion of those twin stages during the course of three seconds as space rocket fuel vented into atmosphere.

They where moving from NE to N and downward at a steep angle, I grabbed the tripod and ran through the lay by onto the pitch black road and into a back road with tall trees to one side, I set the camera down fast to compose another image hoping that the vibration didn't knock the delicate focus of the nifty fifty lens. This was the moment which will stay with me forever, to the naked eye all I could see were two bright naked eye comets with tails moving across the background stars with fanned 'dust tails', the upper most comet was exceptionally bright, much brighter than planet Jupiter to the SW, these were casting shadows on the ground, I reckoned they were at least as bright as planet Venus in the mag -4 to -5 range with vivid white fans. I managed to frame the stages with the tops of the trees to get that much needed Earth-sky connection which really helped the composition with them both in the rule of thirds.

Same settings, 50mm at F/2 ISO1600 and 3 second exposure, any longer and the upper stages would blur dramatically across the frame, I actually needed shorter exposures and higher ISOs but with my crop sensor I couldn't get any more out of the camera so this was the ideal settings I could use, I had to think of these things on the spot in real time as this event was unfolding.

I had just enough time to get a few exposures and glance up into the sky to observe these twin comets, they seemed to be getting even brighter yet at the same time where dropping in altitude fast towards the trees, soon they would be out of view.

Crop from the above image, I couldn't believe I was actually seeing this, a rare event ticked off my list which I never thought I would ever experience in this country.

My second last image, I opened the aperture fully to F/1.8 to get a shorter shutter speed and captured it just as it entered a bank of clouds low in the north, if I was religious I would have described it as a celestial Angel. My last exposure was of cloud and stars, the rocket stages were glowing through the cloud then vanished from view.

I was on a high after seeing that, I had to keep looking at the images on the camera just to convince myself that it had actually happened. I drove on down to the stone circles and met Hugh from Embrace Tours, he and a few others had also observed the deburn and even captured using their mobile phones. As it turned out many people had seen it across UK and Ireland, it was even captured over light polluted towns and even over Belfast, the majority of the sightings were chance encounters and many didn't know what was happening which added to the excitement. The following day NASA's amateur Astronomy website Spaceweather.com updated with more information...

''Last night, sky watchers in Europe saw a bright comet glide across the night sky. Where did it come from? Hint: It was made of rocket fuel. Many witnessed the ascent of NASA's new Landsat 9 satellite. It blasted off Sept. 27th (18:12 UT) from California's Vandenberg Air Force Base onboard an Atlas V rocket. A few hours later, the rocket's Centaur upper stage executed a deorbit burn and that's what European sky watchers saw. Landsat 9 is now in orbit, joining its predecessor Landsat 8 in mapping urban sprawl, wildfires, the retreat of glaciers and many other changes to planet Earth. The latest member of the Landsat family carries two new cutting-edge instruments: the Operational Land Imager 2 (OLI-2) and the Thermal Infrared Sensor 2 (TIRS-2). These can detect minute changes in lakes, rivers and forests by analyzing light reflected from Earth's surface''.

I can now place this event in my extremely rare catalogue along side Nacreous Clouds, thanks very much to Will Gater for that post, I'm glad I trusted my instincts and made the effort to go out under a proper dark sky, the experience is something which I will never forget!! thanks very much for reading.


Martin McKenna

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