On February 24, running through March 10, 2022, the watch begins for the perfect opportunity to launch a sounding rocket into a common but rarely-viewed type of aurora: the pulsating aurora. The NASA Loss through Auroral Microburst Pulsations (LAMP) mission will send instruments high above the auroral light. Read on to find out what the target is, and how citizen scientists can help. Follow real-time launch updates here and see their nightly blog for more detailed updates. You can also find a printable, family-friendly flyer about the mission here.
Note: Always prioritize safety when chasing aurora! Check out these tips by Aurorasaurus Ambassador Hugo Sanchez.
What are pulsating auroras?
Video by Chris Ratzlaff. CW: Because pulsating auroras flash on and off,
Pulsating aurora, a type of “diffuse” aurora, occurs after more dramatic “discrete” auroras, often in the time before dawn. “Poetically minded observers have likened it to the beating of a gigantic light-filled heart in the heavens; the less poetic have thought in terms of a malfunctioning neon sign.” (Helferrich, 1993). It is extremely dim, however, and is often missed by photographers taking a break between substorm peaks in auroral displays. “Pulsating aurora rewards the patient. It often marks the closing phase of an auroral display, appearing some time after the other activity has stopped.” (Helferrich, 1993).
According to the out of print but excellent Aurora Watcher’s Handbook by T. Neil Davis, “To see pulsating aurora, a watcher should look overhead during the minutes or hours following the appearance and subsequent disappearance of discrete aurora…making sure that your eyes are well dark-adapted. The aurora will probably look patchy at this time. Fasten the eyes on one patch. Within a few seconds, that patch will probably disappear, but it will reappear a few seconds later….A look to the east and west of the one seen will reveal many more. Once pulsating auroras occur in the sky, they may continue for hours, perhaps until dawn” (Davis, 1992, p. 50). Have you seen the pulsating aurora?
Less poetically, “Both pulsating arcs and patches are seen; the most obvious to the human observer are large pulsating patches, usually bigger than the Big Dipper from handle to cup. These patches blink on and off every few seconds; the most common periodicity [how often it blinks] is 6 to 10 seconds. Many pulsating auroral patches may be seen in the sky at one time. Each seems to have its own temporal behavior pattern, quite independent of its neighbors” (Davis, 1978).
But why do patches pulsate, turning on and off? “A rock dropped in a pond generates waves that travel across the water, and the plucking of a violin string produces audio waves. During substorms, a certain amount of rock-dropping and string-plucking transpires in the magnetosphere and the ionosphere, generating waves of various sorts….The various waves running around in the magnetosphere and the ionosphere may be important to the particles that are moving through too, because the particles and the waves may interact in ways that might slow down or speed up the particles. Wave-particle interactions—the waves speeding up or slowing down the particles, and the particles modifying the waves—perhaps are the cause of the pulsating aurora” (Davis, 1992, p. 160).
The Earth’s magnetic field is shaped roughly like a dipole magnet, and electrons rapidly bounce between the north and south poles. If this cloud of bouncing electrons were visible in 3D, it would look like a donut that wraps around the Earth. This structure is called the Outer Van Allen Radiation Belt. Some of the processes that accompany an auroral substorm trigger a special kind of wave called a “chorus wave”, which jostles the radiation belt and loosens medium-high energy electrons. These particles surf the chorus waves toward Earth and plunge deep into the upper atmosphere in a natural process that influences atmospheric chemistry.
In summary, pulsating auroras occur most frequently over wide regions at lower latitudes from the hours of midnight to dawn, because in that special place the medium-high energy electrons and chorus waves sync up. Interactions between the chorus waves and the particles lead to the on-off nature of the pulsating lights.
LAMP: Shedding Light on Pulsating Aurora
The LAMP mission is a set of scientific instruments on board a 40-foot (12.2m) rocket that will fly into a pulsating aurora, launched from the University of Alaska Geophysical Institute’s (UAFGI) Poker Flat Research Range. The team is from NASA Goddard, the University of Iowa, the U.S. Air Force Academy, the University of Electro-Communications, Tokyo, the University of New Hampshire (UNH), Dartmouth College, Tohoku University, Kyutech Institute of Technology, Nagoya University, and JAXA. There will also be several special ground cameras in the area to get a clearer picture of the on-off pattern of pulsation. They will join the rocket in looking for even higher-frequency flickering embedded within it. The instruments will measure a number of things related to particles and waves that drive the pulsating aurora and the high frequency flickering which may be related to another similar phenomenon called microbursts. While we usually hear about microbursts in the context of severe thunderstorms, the aurora science definition is very different. On scientific instruments, microbursts look like concentrated, sudden, intense rains of super-high energy particles like those usually found in the outer radiation belt. LAMP wants to find out whether the microbursts happen in the same time and place as pulsating patches, and how they could be related to the pulsations.
Be a Rocket Citizen Scientist!
Because the pulsating aurora is visible over great distances, citizen scientists in Alaska and beyond can contribute valuable information. There are several ways to participate:
- What do you want to know about the science of pulsating aurora? Science questions are the foundation of research, and the team wants to hear what piques your curiosity. This month (February 2022), you can submit your questions on Twitter by tagging both @LAMP_rocket and @tweetaurora, or by email at firstname.lastname@example.org. We will do our best to answer the question, explain why it is a mystery, and/or see if LAMP might be able to help solve the puzzle!
- If you are an aurora photographer anywhere aurora is visible and are interested in photographing pulsating aurora, you can help by submitting your observations to Aurorasaurus. To participate, go to aurorasaurus.org and click “Yes” next to “Did You See the Aurora?” at the top of the page. Then, fill out the quick form.
Pulsating auroras can cover enormous areas, so scientists can use multiple observations to triangulate measurements and look at a structure from different angles. Photographic observations with your location, when you see it, and how broad an area it covers are important, even if the rocket isn’t launching that night.
We are often asked what makes a good science photo of aurora.The timescales of pulsating aurora movement are difficult to capture, so timelapses with as short a time as possible are ideal. Color photos are also ideal for finding out whether photography cameras are able to capture the color variations of pulsating aurora. In most cases, though, the best photo is any you would like to share!
Bonus mission (should you choose to accept it): The shapes and on/off nature of the pulsating aurora can create some curious forms. Can you capture the weirdest structures? We will send Aurorasaurus bumper stickers to the 3 people with the most scientifically intriguing photos!
Last tag until I drop my timelapse I know everyones’ twitters are blowing up today😂. Just wanted to share some real-time of the pulsating aurora last night; so fast and colorful. Seen from in town (bortle 8).@TamithaSkov @AuroraJAnderson @ItsAstroKota @KimHinesSN @LachDonna pic.twitter.com/aK8ay9Gxmq
— Vincent Ledvina (@Vincent_Ledvina) November 4, 2021
Again, be sure to follow the mission’s Twitter for real-time launch updates and nightly blog for more information. You can also check out Aurorasaurus for more aurora citizen science and to learn more about aurora science. We can’t wait to learn more together!
“Cultural Connections: The Northern Lights,” University of Alaska Fairbanks Geophysical Institute, https://culturalconnections.gi.alaska.edu/.
Davis, T. Neil, The Aurora Watcher’s Handbook, Fairbanks, University of Alaska Press, 1992.
Davis, T. Neil, “Hints for Aurora Watching,” University of Alaska Fairbanks Geophysical Institute Alaska Science Forum blog, 1981 https://www.gi.alaska.edu/alaska-science-forum/hints-aurora-watching-0
Davis, T. Neil, “Pulsating Aurora,” University of Alaska Fairbanks Geophysical Institute Alaska Science Forum blog, 1978 https://www.gi.alaska.edu/alaska-science-forum/pulsating-aurora
Helfferich, Carla, “Eye Troubling Auroras,” University of Alaska Fairbanks Geophysical Institute Alaska Science Forum blog, 1993 https://www.gi.alaska.edu/alaska-science-forum/eye-troubling-auroras
Jaynes, Allison, “The origin of pulsating auroras”, Nature https://www.nature.com/articles/d41586-018-01669-z
Jaynes, Allison, “Types of Auroras,” Aurorasaurus blog, http://blog.aurorasaurus.org/?p=168
Tebolt, Michelle, “Lava Lamp or the aurora?” Aurorasaurus blog, http://blog.aurorasaurus.org/?p=511