Today's Image of the Day from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency</a> features Hurricane Otis as it was approaching Mexico’s southern Pacific coast on October 24, 2023. The image was captured by Copernicus Sentinel-3’s Ocean and Land Colour Instrument. 



"Originally classified as a tropical storm, Otis was upgraded in just 12 hours to a category five hurricane – the most dangerous rating for a hurricane – shocking forecasters and local authorities alike," said ESA.



Hurricane Otis surpassed Hurricane Patricia as the strongest landfalling Pacific hurricane on record. The hurricane's rapid growth was influenced by a combination of factors, including light to moderate southeasterly wind shear, high sea surface temperatures (86–88 °F or 30–31 °C), which were above average due to a record-warm September in Mexico, an ongoing El Niño, and the influence of global warming.&nbsp;



These conditions provided a favorable environment for Otis to intensify dramatically. A jet streak in the jet stream further accelerated the hurricane's development by dispersing latent heat and fostering convective development.



The hurricane's core made landfall just west of Acapulco around 1:25 a.m. CDT at peak intensity. The storm caused immense damage.



"Acapulco, which is home to almost one million people, is covered by storm clouds in the image. It was one of the worst places hit," said ESA.



"Mexico City, the country’s huge, densely populated capital, can be seen as a brown area in the cloud-free part of the image north of the hurricane. The Popocatépetl active volcano can also be spotted about 70 km southeast of Mexico City."



The rapid intensification of Otis was one of the most poorly forecast events in recent years. Forecast models struggled to predict the storm's strength and speed, and there were very few instruments available for evaluating hurricane strength in the East Pacific.&nbsp;



Otis' small size, extending hurricane-force winds only about 30 miles from its center, made it more prone to rapid changes in intensity.&nbsp;



Image Credit: ESA



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Otis was the strongest landfalling Pacific hurricane on record

Today's Image of the Day from the European Space Agency...

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the reddish-brown waters of the Betsiboka River Delta in Madagascar. It is one of the most visually striking river deltas in the world, especially when viewed from space.



The Betsiboka River is the largest river in Madagascar by discharge, and its delta is equally significant. The river flows into Bombetoka Bay, which further leads to the Mozambique Channel.



One of the most notable characteristics of the Betsiboka River Delta is its bright color when viewed from space.



"In this case, the color is caused by the transport of iron-rich sediment. The sediment can clog waterways in the delta’s estuarine environment, but it can also form new islands that become colonized by mangroves. Many other water bodies, such as the reservoir fed by the Jacui River in southern Brazil, are colored by reddish sediment," said NASA.



"Despite their rusty color, these arteries of water are important for biodiversity. Algae and other microorganisms serve as a vital food source for vulnerable bird species, such as the Andean flamingo in the Laguna Colorada. Within the Betisboka River Delta, the estuary provides food, such as seagrasses, to the endangered green turtle and vulnerable dugong, or sea cow."



The photo was captured by an astronaut on the space station on September 30, 2023.



Image Credit: NASA Earth Observatory&nbsp;



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The Betsiboka River Delta in Madagascar

Today's Image of the Day from NASA Earth Observatory features...

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features an astronaut view of the northeast coast of Somalia. This region, which borders the Indian Ocean, has a mix of sandy beaches and rugged cliffs



"The detailed image reveals a desert landscape etched by wind and water," said NASA. "Over time, streams have cut canyons into the earth. But streams in this region are ephemeral, making groundwater the main source of fresh water."&nbsp;



"The water table is shallow (wells are typically drilled less than 20 meters deep) and meets the surface toward the coast, creating springs."



"Bidirectional winds sculpted the tan, brown, and reddish sand into transverse sand dunes visible near the stream’s deltas. The orientation of the sand dunes indicates that they were likely formed by summer winds blowing up the coast from the southwest."



The economy of northeast Somalia is primarily based on fishing, livestock, and trade. The long coastline provides ample opportunities for fishing, which is a significant source of food and income.



The region is home to important port cities like Bosaso, which is a hub for trade and commerce. These ports are vital for both the local and national economy.



The area is rich in cultural heritage, with a history that dates back to ancient times. It is believed to be part of the ancient Land of Punt, known for its trade relations with ancient Egypt.



The climate is typically hot and dry, with irregular rainfall. This environment shapes the lifestyle and agricultural practices of northeast Somalia.



Despite the arid conditions, the region supports a variety of wildlife, including species adapted to desert and semi-desert habitats.



The photograph was captured on August 9, 2023 as the International Space Station orbited over the Horn of Africa.



Image Credit: NASA Earth Observatory&nbsp;



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Northeast Somalia: A landscape shaped by wind and water

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features Cyclone Michaung, which slammed into the southern Indian coast on December 5, 2023 with intense winds and torrential rainfall. Michaung made landfall between Nellore and Kavali in the state of Andhra Pradesh. 



"When it made landfall, the storm had sustained winds of 90 to 100 kilometers (56 to 62 miles) per hour, according to the India Meteorological Department," said NASA.



"The VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 satellite captured this image after landfall, as the weakening storm moved northward and winds had slowed to 65 to 75 kilometers per hour."



As the cyclone approached, tall waves crashed into southern coastal towns and entire villages were submerged, according to a report from Reuters. Trees were uprooted, roads were damaged, and cars were swept away.&nbsp;



By Wednesday, rescue operations were launched in Chennai, a city of over six million people. Rescuers used inflatable rafts and ropes to pull people from their flooded homes and air force helicopters dropped food to some of those who remained stranded.



Among the widespread destruction, there have been 13 confirmed deaths due to causes including falling structures and electrocution.



Cyclones are relatively common along the southern coast of India, particularly in the Bay of Bengal and the Arabian Sea. This region is prone to cyclonic activity primarily due to its geographical location and certain meteorological factors.&nbsp;



Cyclones in this area tend to occur mainly in two seasons: the pre-monsoon season (April-June) and the post-monsoon season (October-December).



During these periods, warm ocean temperatures, high humidity, and favorable wind patterns contribute to the development and intensification of cyclones.



Image Credit: NASA Earth Observatory&nbsp;



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Cyclone Michaung caused widespread destruction in southern India

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features a volcanic plume drifting from Anak Krakatau, a small island in the Sunda Strait between the islands of Java and Sumatra in Indonesia. 



Anak Krakatau, which means "Child of Krakatoa," emerged from the sea in 1927, forming over the caldera of the infamous Krakatoa volcano, which erupted catastrophically in 1883.&nbsp;



This earlier eruption was one of the most violent volcanic events in recorded history, known for its immense power and the global climate impact it had due to the large amount of ash it sent into the upper atmosphere.



Anak Krakatau has been growing continuously since its emergence, with frequent eruptions that have reshaped its structure and size over time.&nbsp;



"Geologists have tallied 57 eruptive periods from this location since the beginning of the Holocene, roughly 11,700 years ago," said NASA. "The most recent eruptive period, which started in May 2021 and continued into December 2023, has featured frequent but generally mild Strombolian blasts of volcanic gases and ash particles."&nbsp;



"Materials ejected from the volcano’s vent are typically lofted a few hundred meters above the summit, and small lava flows occasionally drain down the island's flanks and into the sea."



"Beginning on November 26, 2023, geologists with the Indonesian Center for Volcanology and Geological Hazard Mitigation began to report more intense explosions, with plumes of volcanic material rising up to 1,000 meters (3,280 feet) above the vent."&nbsp;



The public has been warned to stay at least 5 kilometers (3 miles) from the crater. Due to elevated risks of ash in the area, the Volcanic Ash Advisory Center in Darwin, Australia, has issued multiple warnings to the aviation community.



The image was captured on December 2, 2023 by the Operational Land Imager (OLI) on Landsat 8.



Image Credit: NASA Earth Observatory&nbsp;



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Volcanic activity has intensified on Anak Krakatau

Closeup,Orion,Constellation,On,Night,Starry,Sky,Above,Forest,Silhouette,

Next week, the night sky will witness an extraordinary astronomical event, as Betelgeuse, one of the most luminous <a href="https://www.earth.com/news/rare-six-planet-star-system-moves-in-strange-perfect-synchrony/">stars</a> in the constellation Orion, temporarily vanishes from view.&nbsp;



This unusual occurrence, set to happen on Monday night, December 11, is due to an asteroid, 319 Leona, passing directly in front of the star, causing it to disappear for approximately 12 seconds.



<h2 class="wp-block-heading" id="h-rare-occlusion-nbsp">Rare occlusion&nbsp;</h2>



Astronomical phenomena like this are not uncommon, but the upcoming event involving Betelgeuse is unique due to the specific alignment that will create a striking ‘ring of fire’ effect.&nbsp;



Observers in Florida, parts of eastern Mexico, southern Europe, and northern Asia will be ideally positioned to witness this rare ‘occlusion.’ For those not in these regions, the <a href="https://www.virtualtelescope.eu/" target="_blank" rel="noreferrer noopener">Virtual Telescope Project</a> in Italy will be streaming the event live from 8 PM Eastern on Monday.



<h2 class="wp-block-heading" id="h-once-in-a-lifetime-opportunity-nbsp">Once-in-a-lifetime opportunity&nbsp;</h2>



This brief occlusion is more than just a spectacular sight; it presents a valuable scientific opportunity. Astronomers are eager to use this time to study the surface of Betelgeuse, a red supergiant sun, which has shown unusual dimming patterns over the past four years.&nbsp;



Miguel Montargès, an astrophysicist at the <a href="https://www.observatoiredeparis.psl.eu/-observatoire-de-paris-.html?lang=en" target="_blank" rel="noreferrer noopener">Paris Observatory</a>, expressed excitement about this event, calling it a “once-in-a-lifetime opportunity.” The occlusion will enable scientists to examine the star’s outer region, which is normally overwhelmed by its bright core.



<h2 class="wp-block-heading" id="h-critical-new-insights">Critical new insights</h2>



This research is expected to provide insights into the ‘convective cells’ of Betelgeuse, which are the pathways for heated gas movement across the star. Montargès anticipates that the data gathered might also enhance understanding of how planetary systems, like our own solar system, form.



Gianluca Masi, director of the Virtual Telescope Project, pointed out that the event will also aid in studying asteroid 319 Leona.&nbsp;



“These kinds of occultations,” Masi stated, "are very useful to constrain the shape of the asteroid involved.” He also noted that this occlusion is not only rare but symbolic of Betelgeuse’s eventual fate. “For a very short time, we will see the legendary Orion constellation without its famous, orange shoulder,” referencing the eventual supernova explosion of Betelgeuse.



<h2 class="wp-block-heading" id="h-viewing-the-betelgeuse-event">Viewing the Betelgeuse event</h2>



Astronomers are meticulously tracking the trajectory of asteroid 319 Leona, with the occultation anticipated to occur around 8:17 PM Eastern Time. Those within the correct viewing line will have the chance to see Betelgeuse, typically the 10th-brightest star, fade from sight, an experience that can be enhanced with binoculars or a telescope.



Even for observers outside the optimal viewing areas, there’s still a chance to witness Betelgeuse dimming in an unusual manner. Residents of the Northern Hemisphere can find Betelgeuse in December by looking east about two hours after sunset, near Orion’s Belt.



For those seeking more information, the <a href="https://occultations.org/" target="_blank" rel="noreferrer noopener">International Occultation Timing Association</a> has dedicated a <a href="https://www.iota-es.de/betelgeuse2023.html" target="_blank" rel="noreferrer noopener">page</a> to the event, complete with a downloadable Google Earth file to assist in tracking the visibility of the event globally.



<h2 class="wp-block-heading" id="h-more-about-betelgeuse">More about Betelgeuse</h2>



Betelgeuse, often pronounced "Beetlejuice," is a red supergiant star that has captivated astronomers and stargazers alike with its distinctive red hue and immense size. Located in the constellation of Orion, it's one of the most easily recognizable stars in the night sky and has been a subject of fascination and study for centuries.



<h3 class="wp-block-heading" id="h-astronomical-significance">Astronomical significance</h3>



As discussed above, Betelgeuse holds a special place in astronomy due to its enormous size and relatively close proximity to Earth. It's one of the largest stars visible to the naked eye, with a radius over 1,000 times that of the Sun. If placed at the center of our solar system, Betelgeuse would engulf the inner planets, reaching out nearly to the orbit of Jupiter.



<h3 class="wp-block-heading" id="h-stellar-characteristics">Stellar characteristics</h3>



This celestial giant is a red supergiant, a stage in the lifecycle of a star that occurs after it has exhausted the hydrogen in its core. During this phase, the star expands significantly and cools down, giving it a distinctive red color. Betelgeuse's surface temperature is around 3,500 Kelvin, much cooler than the Sun’s 5,778 Kelvin.



<h3 class="wp-block-heading" id="h-variability-and-brightness">Variability and brightness</h3>



Betelgeuse is a variable star, meaning its brightness changes over time. These fluctuations in brightness are due to complex processes happening in its vast, bubbling surface. The star’s light can vary in a somewhat irregular pattern, making it a subject of interest for those studying stellar behavior.



<h3 class="wp-block-heading" id="h-distance-and-visibility">Distance and visibility</h3>



Located approximately 642 light-years from Earth, Betelgeuse is relatively close in astronomical terms, allowing for detailed observation. Its brightness usually ranks it among the top ten brightest stars in the night sky, making it easy to spot even in areas with moderate light pollution.



<h3 class="wp-block-heading" id="h-future-supernova">Future supernova</h3>



One of the most intriguing aspects of Betelgeuse is its potential future as a supernova. Astronomers predict that within the next million years, Betelgeuse will exhaust its nuclear fuel and undergo a spectacular supernova explosion. This event will be so bright that it will be visible from Earth even during the day and will mark the end of this star’s life cycle.



<h3 class="wp-block-heading" id="h-cultural-and-historical-impact">Cultural and historical impact</h3>



Betelgeuse has also played a significant role in various cultures and mythologies. Its position in the constellation of Orion, a prominent figure in Greek mythology, and its visibility across the globe have made it a point of interest and storytelling for many civilizations.



In summary, Betelgeuse stands as a magnificent example of the wonders of the universe. Its immense size, changing brightness, and inevitable fate as a supernova continue to make it a subject of both scientific study and popular fascination. As we gaze upon this red supergiant, we are reminded of the vastness and beauty of the cosmos.



<h2 class="wp-block-heading" id="h-more-about-the-orion-constellation">More about the Orion constellation</h2>



As discussed above, <a href="https://universe.nasa.gov/news/147/discovering-the-universe-through-the-constellation-orion/" target="_blank" rel="noreferrer noopener">the Orion constellation</a>, one of the most recognizable and prominent constellations in the night sky, captivates observers across the globe. Named after the Greek mythological hunter, Orion, this constellation not only boasts significant astronomical importance but also holds a rich cultural and mythological heritage.



<h3 class="wp-block-heading" id="h-astronomical-features-of-orion">Astronomical features of Orion</h3>



Orion is home to some of the brightest stars in the night sky. Betelgeuse, the protagonist of this article, marks Orion's right shoulder. Bellatrix serves as his left shoulder. Rigel, a brilliant blue-white star, represents Orion's left foot, and Saiph constitutes his right knee. These stars form the distinct hourglass shape of the constellation.



A striking feature of Orion is his belt, comprised of three aligned stars: Alnitak, Alnilam, and Mintaka. Below the belt, the <a href="https://www.earth.com/news/jumbos-james-webb-reveals-free-floating-worlds-that-cant-be-explained/" target="_blank" rel="noreferrer noopener">Orion Nebula </a>(M42), a vibrant, star-forming region, dazzles astronomers and astrophotographers alike. This nebula, visible to the naked eye under dark skies, is a popular target for telescopic observation.



<h3 class="wp-block-heading" id="h-orion-in-culture-and-mythology">Orion in culture and mythology</h3>



In Greek mythology, Orion is depicted as a formidable hunter, often associated with tales of bravery and prowess. Various cultures have their own interpretations of this constellation, each adding to its rich narrative tapestry.



The stars of Orion have been significant in various ancient civilizations, from the Egyptians, who associated the constellation with Osiris, the god of the afterlife, to the Native American cultures, where it held various meanings and stories.



In summary, Orion continues to be a source of wonder and inspiration. Its prominent place in the night sky makes it a gateway for amateur astronomers and a subject of ongoing study for professionals. Whether it's through the lens of science, culture, or mythology, the Orion constellation remains an enduring and captivating presence in our night sky.



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The Betelgeuse star in constellation Orion will vanish from sight this week

Next week, the night sky will witness an extraordinary astronomical...

New research led by Dr. Florian Klein at the <a href="https://portal.uni-koeln.de/en/uoc-home" target="_blank" rel="noreferrer noopener">University of Cologne</a> has revealed incredible new details about how the immune system responds to <a href="https://www.earth.com/news/new-clues-about-the-household-spread-of-covid-19/">SARS-CoV-2</a> and its variants. 



Despite the familiarity of the immune system with the virus, new variants continue to present challenges.&nbsp;



Two recent studies from Dr. Klein's group have shed light on the evolution of the antibody response to SARS-CoV-2 and the immune system's proactive strategies against emerging variants.



<h2 class="wp-block-heading" id="h-affinity-maturation-nbsp">Affinity maturation&nbsp;</h2>



One of the key processes in this battle is "affinity maturation," where antibodies mature over time through mutations of individual amino acids. This maturation enhances the detection and neutralization of infectious pathogens.&nbsp;



The researchers found that an infection with the Omicron variant triggers a renewed immune response in vaccinated individuals, primarily through the reactivation of memory B cells.&nbsp;



Interestingly, the antibodies produced by these cells had matured even before the emergence of Omicron, suggesting that the immune system was preemptively prepared.



<h2 class="wp-block-heading" id="h-focus-of-the-study">Focus of the study</h2>



“Our first goal was to investigate how the antibody response in healthy subjects changes through a third vaccination against the original SARS-CoV-2 strain,” said study first author and doctoral candidate Svea Rose.



“We were initially surprised by the results. Although the third vaccination significantly increased the SARS-CoV-2 immune response overall, there was hardly any further maturation at the level of individual antibodies.”&nbsp;



<h2 class="wp-block-heading" id="h-affinity-maturation-nbsp-0">Affinity maturation&nbsp;</h2>



Further analysis, particularly in individuals infected with Omicron variants BA.1 and BA.2 post-vaccination, revealed that memory B cells that were capable of forming antibodies to neutralize the Omicron variant had proliferated.&nbsp;



According to the study's first author Dr. Timm Weber, these immune cells were already in existence prior to contact with the Omicron variant.&nbsp;



“Interestingly, the immune cells directed against the Omicron variant were already present before contact with Omicron and were not induced by Omicron,” said Dr. Weber.&nbsp;



<h2 class="wp-block-heading" id="h-proactive-response-nbsp">Proactive response&nbsp;</h2>



Furthermore, the team discovered broad neutralizing antibodies - which had appeared early on in the pandemic - that were effective against all tested new variants.



The working group also looked at the molecular mechanism of affinity maturation. The clock was turned back and individual antibodies, which were isolated throughout the world in the first year of the pandemic, were restored to their original state, explained study lead authors Michael Korenkov and Dr Matthias Zehner.&nbsp;



<h2 class="wp-block-heading" id="h-random-modifications-nbsp">Random modifications&nbsp;</h2>



The analysis revealed that some modifications during affinity maturation occur randomly, and surprisingly, these random modifications were crucial for neutralizing the Omicron variants.



“The immune system expands the arsenal of existing antibodies by inserting arbitrary mutations and thus increases the likelihood of having a suitable antibody in the repertoire when a new virus variant appears,” explained Dr. Christoph Kreer, who led the study together with Professor Klein.&nbsp;



This insight led to the modification of a therapeutic antibody, previously ineffective against Omicron, to effectively neutralize Omicron variants.



<h2 class="wp-block-heading" id="h-study-implications-nbsp">Study implications&nbsp;</h2>



Ultimately, these studies not only illuminate how the human immune system reacts to a new virus and its evolving variants but also highlight the potential therapeutic and preventive applications of the newly isolated broad neutralizing antibodies against newer Omicron variants.&nbsp;



The research marks a significant advancement in our understanding of the immune system's adaptability and resilience in the face of emerging viral threats.



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.immuni.2023.11.004" target="_blank" rel="noreferrer noopener">Immunity</a>.



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Our immune system has a proactive response to Covid variants

New research led by Dr. Florian Klein at the University...

The,Ethereal,Beauty,Of,The,Aurora,Borealis,,Also,Known,As

The enchanting auroras, with their vibrant displays of green, red, and purple curtains, have long captivated observers of the night sky. However, the recent emergence of peculiar aurora-like phenomena -- the mauve and white streaks known as "Steve" and their often accompanying <a href="https://www.earth.com/wp-content/uploads/2023/12/aurora_Steve_green_1medium.jpg" target="_blank" rel="noreferrer noopener">glowing green</a> "picket fence" -- has intrigued scientists and sky-watchers alike. 



First identified in 2018 as distinct from the more familiar <a href="https://www.earth.com/news/aurora-borealis-seen-as-far-south-as-the-equator-after-largest-known-solar-storm/" target="_blank" rel="noreferrer noopener">auroras</a>, Steve, named after a character in a 2006 children's movie, and the picket fence phenomenon were initially believed to be products of the same physical processes as the auroras. However, this assumption left many questions unanswered about the origins of their unique glowing emissions.



<h2 class="wp-block-heading" id="h-new-mechanism-is-generating-sky-glows">New mechanism is generating sky glows</h2>



Enter Claire Gasque, a promising graduate student in physics at the <a href="https://www.berkeley.edu/" target="_blank" rel="noreferrer noopener">University of California, Berkeley</a>. Gasque has proposed an intriguing explanation for these phenomena, suggesting a physical mechanism vastly different from those responsible for the traditional auroras.



"This would upend our modeling of what creates light and the energy in the aurora in some cases," Gasque said. "It's really cool, one of the biggest mysteries in space physics right now."



Collaborating with the Space Sciences Laboratory (<a href="https://www.ssl.berkeley.edu/" target="_blank" rel="noreferrer noopener">SSL</a>) at Berkeley, Gasque advocates for a <a href="https://www.nasa.gov" target="_blank" rel="noreferrer noopener">NASA</a> mission to launch a rocket into an aurora to validate her hypothesis. This research coincides with the sun entering a more active phase of its <a href="https://www.earth.com/news/northern-lights-activity-will-intensify-over-the-next-18-months/" target="_blank" rel="noreferrer noopener">11-year cycle</a>, making this an opportune moment for studying rare events like Steve and the picket fence.



<h2 class="wp-block-heading" id="h-distinguishing-steve-from-a-common-aurora">Distinguishing "Steve" from a common aurora</h2>



Gasque's research focuses on the peculiar behavior of electric fields in the upper atmosphere. She suggests that these fields, parallel to <a href="https://www.earth.com/earthpedia-articles/earths-magnetic-field-origin-structure-and-impact-on-humanity/" target="_blank" rel="noreferrer noopener">Earth's magnetic field</a>, might produce the color spectrum observed in the picket fence phenomenon.



This hypothesis challenges existing models of <a href="https://www.earth.com/news/northern-lights-captivated/" target="_blank" rel="noreferrer noopener">auroral light</a> and energy generation and has significant implications for our understanding of the interaction between Earth's magnetosphere and the ionosphere.



Common <a href="https://www.earth.com/news/breathtaking-red-auroras-ignited-northern-hemisphere-skies-this-week/" target="_blank" rel="noreferrer noopener">auroras</a> result from solar wind energizing particles in Earth's magnetosphere, causing oxygen and nitrogen molecules in the upper atmosphere to emit specific frequencies of light. 



Steve, however, exhibits a broad range of frequencies centered around purple or mauve, without the blue light typical of the most energetic particle interactions in auroras. Interestingly, Steve and the picket fence occur at lower latitudes than typical auroras, potentially even near the equator.



<h2 class="wp-block-heading" id="h-parallel-electric-fields-at-play">Parallel electric fields at play</h2>



Gasque's research posits that the emissions from the "picket fence" are generated by low-altitude electric fields parallel to Earth's magnetic field. Employing a widely accepted physical model of the ionosphere, she demonstrated that a parallel electric field of approximately 100 millivolts per meter at an altitude of about 110 km could accelerate electrons. 



This acceleration is sufficient to energize oxygen and nitrogen atoms, resulting in the emission of the <a href="https://svs.gsfc.nasa.gov/12865" target="_blank" rel="noreferrer noopener">spectrum of light</a> observed in the "picket fence" and "Steve" aurora. She also identified unique conditions in this region, such as a reduced plasma density and an increased presence of neutral oxygen and nitrogen atoms. These could serve as an insulator, preventing the electric field from short-circuiting.



"If you look at the spectrum of the picket fence, it's much more green than you would expect. And there's none of the blue that's coming from the ionization of nitrogen," Gasque said. "What that's telling us is that there's only a specific energy range of electrons that can create those colors, and they can't be coming from way out in space down into the atmosphere, because those particles have too much energy."



Instead, she said, "the light from the picket fence is being created by particles that have to be energized right there in space by a parallel electric field, which is a completely different mechanism than any of the aurora that we've studied or known before."



<h2 class="wp-block-heading" id="h-searching-for-steve-with-rockets">Searching for Steve with rockets</h2>



<a href="https://www.ssl.berkeley.edu/full-directory/name/brian-harding/" target="_blank" rel="noreferrer noopener">Brian Harding</a>, an assistant research physicist at SSL and co-author of Gasque's paper, highlights the significance of this discovery. 



"The really interesting thing about Claire's paper is that we've known for a couple of years now that the Steve spectrum is telling us there's some very strange physics going on. We just didn't know what it was," said&nbsp;Brian. "Claire's paper showed that parallel electric fields are capable of explaining this strange spectrum."



The team proposes launching rockets from Alaska to measure electric and <a href="https://www.earth.com/news/solar-wind-collides-magnetic-field/" target="_blank" rel="noreferrer noopener">magnetic fields</a> within these phenomena, aiming to validate their hypotheses. This endeavor aligns with NASA's Low Cost Access to Space (<a href="https://www.science.gov/topicpages/l/low-cost+space+access" target="_blank" rel="noreferrer noopener">LCAS</a>) program and is expected to deepen our comprehension of the upper atmosphere's chemistry and physics. Initially, the target would be what's known as an enhanced aurora, which is a normal aurora with "Steve" and "picket fence"-like emissions embedded in it.



"The enhanced aurora is basically this bright layer that's embedded in the normal aurora. The colors are similar to the picket fence in that there's not as much blue in them, and there's more green from oxygen and red from nitrogen. The hypothesis is that these are also created by parallel electric fields, but they are a lot more common than the picket fence," Gasque said.



The plan is not only "to fly a rocket through that enhanced layer to actually measure those parallel electric fields for the first time," she said, but also send a second rocket up to measure the particles at higher altitudes, "to distinguish the conditions from those that cause the auroras." Eventually, she hopes for a rocket that will fly directly through "Steve and the "picket fence."



<h2 class="wp-block-heading" id="h-curiosity-drives-this-steve-aurora-research">Curiosity drives this "Steve" aurora research</h2>



Gasque credits her success to collaborations with experts studying various atmospheric layers, including the mesosphere and stratosphere. This interdisciplinary approach enabled significant progress in understanding the difference between an aurora and Steve. 



Harding, Gasque, and their colleagues submitted a proposal to NASA for a sounding rocket campaign this fall, anticipating a response about its selection in the first half of 2024. Gasque and Harding view the experiment as a crucial step towards comprehending the chemistry and physics of the upper atmosphere, ionosphere, and <a href="https://www.earth.com/news/geomagnetic-storms-are-influenced-by-earths-atmosphere/" target="_blank" rel="noreferrer noopener">Earth’s magnetosphere</a>. 



"It's fair to say that there's going to be a lot of study in the future about how those electric fields got there, what waves they are or aren't associated with, and what that means for the larger energy transfer between Earth's atmosphere and space," Harding said. "We really don't know. Claire's paper is the first step in the chain of that understanding."



The team eagerly awaits NASA's decision on their proposed rocket campaign, anticipated in the first half of 2024.



In summary, the research led by Claire Gasque marks a pivotal advancement in space physics. Gasque has shed light on the elusive nature of "Steve" and the "picket fence" as being something other than an aurora. As the solar cycle progresses, these findings promise not only to unravel the mysteries of these phenomena but also to enhance our broader understanding of the dynamic interplay between Earth and space.



<h2 class="wp-block-heading" id="h-more-about-auroras">More about auroras</h2>



Auroras, commonly known as the Northern and Southern Lights, stand as a mesmerizing natural light show in the Earth's polar skies. They occur due to the fascinating interplay between the Earth's atmosphere and solar winds.



As discussed in detail above, scientists believed that the "Steve" and the "picket fence" phenomenon resulted from the same physical processes as an aurora. However, this belief left many questions unanswered about the origins of their unique glowing emissions.



<h3 class="wp-block-heading">Origin: The solar connection</h3>



The Sun, a powerhouse of energy and particles, constantly emits solar winds, streams of charged particles. These particles, on their journey towards Earth, encounter the Earth's magnetic field, which plays a crucial role in the formation of auroras.



Upon reaching Earth, the solar winds get influenced by its magnetic field. The Earth's magnetic field, extending into space, acts as a shield and directs these particles towards the poles. Here, the magnetic field lines funnel these charged particles into the Earth's upper atmosphere.



<h3 class="wp-block-heading">Science of "Steve" and aurora displays</h3>



The core phenomenon of auroras occurs when these charged particles, primarily electrons, collide with gases like oxygen and nitrogen in the Earth's atmosphere. This collision transfers energy to the gas molecules, exciting them and causing them to emit light - the essence of auroral displays. 



The specific colors of the aurora and of Steve, ranging from greens and reds to blues and purples, depend on the type of gas involved and the altitude of these interactions.



Solar activity significantly impacts the intensity and frequency of auroras. During the solar maximum, increased solar flares and coronal mass ejections result in more intense and frequent auroras. Conversely, the solar minimum leads to reduced auroral activity.



<h3 class="wp-block-heading">Cultural and historical significance</h3>



Beyond their visual splendor, auroras offer valuable insights into the Earth's magnetosphere dynamics and its interaction with solar radiation. The study of auroras contributes to our understanding of how the Earth's magnetic field protects us from harmful solar emissions.



Auroras have held a special place in various cultures, inspiring myths and folklore. From being seen as the Valkyries' shields in Norse mythology to representing ancestral spirits in indigenous beliefs, auroras have been a source of wonder and inspiration throughout history.



In summary, auroras, with their breathtaking beauty, are more than just a visual spectacle. They are a dynamic interaction between solar winds and our planet's magnetic field, offering insights into Earth's protective shield and continuing to captivate people across cultures and generations.



The full study is published in the journal <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL106073" target="_blank" rel="noreferrer noopener">Geophysical Research Letters</a>.



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