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

Today's Image of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features a false-color image of Lake Abbe in northeast Ethiopia. The image was captured by the Copernicus Sentinel-2 mission.&nbsp;



"Visible as the large round dark area, Lake Abbe, also known as Lake Abhe, straddles the border of Ethiopia to the west and Djibouti to the east. The lake is 19 km wide and 17 km long and is extremely salty. It is dotted with clusters of steaming limestone chimneys and surrounded by large salt flats, visible in white, and rift volcanoes," says ESA.



"The biggest volcano in the image is Mount Dama Ali, a dormant 25-km-wide shield volcano that rises on the northwest shore of the lake."



"Lake Abbe and Lake Afambo, which is visible at the top of the image, are part of a chain of six connected salt lakes, fed by the Awash River - one of Ethiopia’s biggest rivers.'



Copernicus Sentinel-2’s near-infrared channel highlights vegetation in bright red. This strategy makes it easy to spot algal blooms, such as the one that is visible in Lake Abbe. According to ESA, the light blue color on the west shore indicates sediment discharged into the lake.



"Because of its dry, desert, almost lunar landscape and the steaming, sulphuric vents, Lake Abbe is considered one of the most inaccessible areas on Earth," says ESA. "Earth observation satellites are key in these cases as they are particularly relevant for monitoring remote regions such as this."



Image Credit: ESA&nbsp;



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Lake Abbe in northeast Ethiopia

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

A recent discovery sheds light on the dietary habits of a juvenile tyrannosaur, revealing its last meal to be two baby <a href="https://www.earth.com/news/dinosaurs-self-regulated-their-body-temperature/" target="_blank" rel="noreferrer noopener">dinosaurs</a>. This finding offers a rare glimpse into the life and development of these prehistoric creatures.



In the Alberta Badlands, a hotspot for dinosaur hunters, a remarkable fossil was unearthed in 2009. It was the ribcage of a juvenile gorgosaurus, a close relative of the T. rex.



<h2 class="wp-block-heading" id="h-juvenile-gorgosaurus">Juvenile gorgosaurus</h2>



After meticulous preparation, researchers at the <a href="https://tyrrellmuseum.com/" target="_blank" rel="noreferrer noopener">Royal Tyrell Museum of Palaeontology</a> discovered the remains of two small bird-like dinosaurs, known as citipes, inside the ribcage.



The juvenile gorgosaurus, about seven years old and weighing approximately 330kg, was in a developmental stage equivalent to a human teenager.&nbsp;Its size was roughly a tenth of a fully grown adult tyrannosaur.&nbsp;



<h2 class="wp-block-heading" id="h-dietary-shifts">Dietary shifts</h2>



The presence of the citipes' hind limbs within its ribcage is "solid evidence that tyrannosaurs drastically changed their diet as they grew up,'' according to Dr. Darla Zelenitsky from the <a href="https://www.ucalgary.ca/" target="_blank" rel="noreferrer noopener">University of Calgary</a>.



The findings highlight a significant shift in the feeding habits of tyrannosaurs as they matured.&nbsp;



"We now know that these teenage (tyrannosaurs) hunted small, young dinosaurs," explained Dr. Zelenitsky.&nbsp;



<h2 class="wp-block-heading" id="h-indiscriminate-eaters">Indiscriminate eaters</h2>



Dr. Francois Therrien described these adult tyrannosaurs as "quite indiscriminate eaters." They probably pounced on large prey, "biting through bone and scraping off flesh," he told BBC News.



But, these immature tyrannosaurs were probably not ready to jump into a group of horned dinosaurs, where the adults weighed thousands of kilograms, said Dr. Zelenitsky.



<h2 class="wp-block-heading" id="h-selective-eaters">Selective eaters</h2>



Interestingly, only the legs of the baby dinosaurs were found inside the gorgosaurus. This suggests that the young tyrannosaur was selective, possibly preferring the meatiest parts.



"The rock within the ribcage was removed to expose what was hidden inside," explained Dr. Therrien. "And lo and behold - the complete hind legs of two baby dinosaurs, both under a year old."



Dr. Zelenitsky said that the teenage gorgosaurus seems to have wanted the drumsticks - probably because that's the meatiest part.



"This animal was selecting and even dissecting its prey - biting off the legs and swallowing them whole."



<h2 class="wp-block-heading" id="h-physical-transformations-nbsp">Physical transformations&nbsp;</h2>



As tyrannosaurs grew, they underwent significant physical transformations. Juveniles were lighter and had blade-like teeth, whereas adults developed rounder teeth, dubbed "killer bananas" by Dr. Therrien.&nbsp;



This change in dentition reflects a shift in feeding strategy from selective predation in juveniles to a more powerful and indiscriminate approach in adults.



The discovery provides a window into the lives of these ancient creatures, debunking the stereotype of dinosaurs as mindless monsters.&nbsp;



<h2 class="wp-block-heading" id="h-sophisticated-feeders-nbsp">Sophisticated feeders&nbsp;</h2>



Professor Steve Brusatte, a palaeontologist from the University of Edinburgh, said that seeing prey in the dinosaur's guts gave a real insight into the animals. "They weren't just monsters, they were real, living things and pretty sophisticated feeders."



In the 1993 film Jurassic Park, a giant T. rex chased a car through a fictional theme park. Professor Brusatte noted that an adult T. rex wouldn't have chased after a car - its body was too big, and it couldn't move that fast.



"It would be the youngsters - (like this gorgosaur) - the children of T. rex that you'd have to keep an eye on."



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Juvenile tyrannosaurs hunted baby dinosaurs 

A recent discovery sheds light on the dietary habits of...

View,Of,Brilliant,Green,Aurora,Shining,Over,Swedish,Foggy,Forest

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 glowing green "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 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.



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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'Steve' phenomenon looks like an aurora, acts like an aurora, but what is it?

The enchanting auroras, with their vibrant displays of green, red,...

A high-speed stream from a coronal hole is expected to lead to G2 (Moderate) geomagnetic storming on December 4 (UTC Day) and G1 (Minor) storming on December 5, 2023, according to an alert this morning from the NOAA Space Weather Prediction Center (<a href="https://www.swpc.noaa.gov/" target="_blank" rel="noreferrer noopener">SWPC</a>).



Coronal holes are striking features of the <a href="https://www.earth.com/news/solar-storms-will-intensify-then-slow-as-the-solar-cycle-peaks-in-early-2024/" target="_blank" rel="noreferrer noopener">Sun</a>, often appearing as dark regions in the solar corona when observed in extreme ultraviolet (EUV) and soft X-ray solar images. These areas are notable for being cooler and less dense compared to the surrounding plasma. The darkness of coronal holes is attributed to their nature as regions of open, unipolar magnetic fields.



<h2 class="wp-block-heading" id="h-role-of-magnetic-fields-in-coronal-holes">Role of magnetic fields in coronal holes</h2>



The open magnetic field line structure of coronal holes is a critical aspect of their behavior. This structure allows the <a href="https://www.earth.com/news/the-solar-wind-which-creates-beautiful-auroras-on-earth-is-now-less-mysterious/" target="_blank" rel="noreferrer noopener">solar wind</a>, a stream of charged particles emitted by the Sun, to escape more easily into space. The result is a stream of relatively fast solar wind, often referred to as a high-speed stream in interplanetary space analysis.



Interestingly, coronal holes can develop at any time and place on the Sun. However, they are more common and persistent around the years of solar minimum. The more persistent coronal holes can last through several solar rotations, each spanning about 27 days.



<h2 class="wp-block-heading" id="h-prevalence-and-stability-of-coronal-holes">Prevalence and stability of coronal holes</h2>



Coronal holes are most prevalent and stable at the solar north and south poles. These polar holes can grow and expand to lower solar latitudes. Additionally, coronal holes can develop in isolation from polar holes, or an extension of a polar hole can split off to become an isolated structure. Persistent coronal holes serve as long-lasting sources for high-speed solar wind streams.



As the high-speed stream interacts with the slower ambient solar wind, a compression region forms, known as a co-rotating interaction region (CIR). From the perspective of a fixed observer in interplanetary space, the CIR will lead the coronal hole high-speed stream (CH HSS).



<h2 class="wp-block-heading" id="h-effects-of-cir-on-planetary-conditions">Effects of CIR on planetary conditions</h2>



The CIR can cause particle density enhancement and interplanetary magnetic field (IMF) strength increases before the onset of the CH HSS. As the CH HSS approaches Earth, solar wind speed and temperature rise, while particle density begins to decrease. After the passage of the CIR and the transition into the CH HSS flow, the overall IMF strength typically starts to weaken.



Coronal holes located near the solar equator are most likely to affect Earth with CIR passage and/or higher solar wind speeds. Strong CIRs and the faster CH HSS can significantly impact Earth’s magnetosphere, causing geomagnetic storms to the G1-G2 levels (Minor to Moderate) on the NOAA Space Weather Scale. 



In rarer cases, stronger storming may occur. The larger and more expansive coronal holes can be a source of high solar wind speeds that affect Earth for extended periods.



<h2 class="wp-block-heading" id="h-forecasting-a-coronal-hole">Forecasting a coronal hole</h2>



Forecasters closely analyze coronal holes for their potential to cause escalated geomagnetic activity and possible storming. They are noted on the daily synoptic drawing. 



The Space Weather Prediction Center (SWPC) forecasters consider the effects of CIR and CH HSS activity when forecasting the anticipated levels of overall planetary geomagnetic response for each 3-hour synoptic period over the next three days, as detailed in the 3-day forecast. Predicted CIR or CH HSS influences are further elaborated in the forecast discussion.



<h2 class="wp-block-heading" id="h-coronal-holes-and-auroras">Coronal holes and auroras</h2>



Coronal holes play a significant role in the creation of <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> on Earth. These dark areas on the Sun's surface, characterized by open magnetic fields, allow solar winds to escape more easily into space. When these high-speed solar winds, often emanating from coronal holes, reach Earth, they can interact with the planet's magnetosphere. This interaction involves the solar wind's charged particles colliding with Earth's magnetic field and atmosphere.



As the solar wind penetrates the magnetosphere, it can cause <a href="https://www.earth.com/news/noaa-alert-strong-geomagnetic-storm-warning-issued-due-to-strong-solar-flare/" target="_blank" rel="noreferrer noopener">geomagnetic storms</a>, especially if the incoming solar wind is strong and fast. These storms disturb the magnetosphere and lead to the acceleration of electrons and protons. When these accelerated particles collide with gases in Earth's upper atmosphere, such as oxygen and nitrogen, they excite these gases, causing them to release photons - the basic units of light. This release of photons results in the shimmering lights known as auroras.



The intensity and frequency of auroras often depend on the strength of the solar wind and the geomagnetic storms it induces. Coronal holes, being significant sources of fast solar winds, can enhance the likelihood and intensity of auroras. During times when Earth encounters streams of solar wind from these coronal holes, the chances of observing auroras at higher and sometimes lower latitudes increase. This phenomenon makes coronal holes an essential factor in predicting and understanding auroral activities on Earth.



In summary, understanding coronal holes and their associated phenomena is crucial for anticipating and mitigating the impacts of solar activity on Earth’s magnetosphere and space weather conditions.



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Massive "coronal hole" in the Sun prompts aurora alert for southern states

A high-speed stream from a coronal hole is expected to...

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Today&#8217;s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> discusses the interesting relationship between humans and meteorites.
A giant piece of a meteorite is central to the DECOS office in the Netherlands, and company founder Paul Vega explains how the four and a half billion-year-old specimen is a symbol of sustainability.
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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer
Video Credit: NASA Goddard

Meteorites represent a sustainable human society