Comets are icy balls of gas, dust and rock that orbit the sun. Astronomers believe most comets are leftovers from the formation of the sun and planets. In fact, comets come from the farthest reaches of the solar system, including the Kuiper Belt and the Oort Cloud. When passing stars outside our solar system jostle comets, the comets begin the long trek inward toward the sun. Then, as they come close to the sun and heat up, they release gas in a process called outgassing. This creates the long, glowing tail that stretches behind the comet and points away from the sun.
The video above is from the Meet the Experts series of the European Space Agency (ESA). In it, comet scientist Charlotte Goetz, formerly of ESA, discusses comets, their formation and their study. Also, she explains that comet nuclei are relatively small – about the size of a small earthly town – and that they are loosely packed balls of ice and dust.
Moreover, the comets we know about are mostly potato-shaped, but some are more oddly shaped. In addition, it’s only when comets come near the sun that they heat up and spew dust and gases. In fact, they develop giant glowing heads – called a comet’s coma – that may be larger than most planets. And indeed, they sprout their long comet tails that stretch millions of miles long.
NASA says that the current number of known comets is 3,979.
The parts of a comet
The nucleus is the core of a comet. Additionally, it is also the head of the comet. When a comet nears the sun and heats up, some of its frozen surfaces begin to thaw and create the fuzzy coma that surrounds the nucleus.
Surprisingly, a comet can have two tails. The ion tail is generally bluish in color and points away from the sun because it’s blown back by the solar wind. The ion tail is made of – you guessed it – ions. These are electrically charged gas molecules. The second tail is the dust tail. It is indeed made of dust and normally has a whiter appearance. The dust tail forms a slightly curved trail behind the path of the comet.
Artist’s concept of the parts of a comet. Image via NASA.
Observing comets
Us skywatchers are, of course, most interested in comets when they appear as (sometimes unexpected, often greenish) visitors in our skies. Since comets are most active when they’re near the sun, we tend to see comets shortly after sunset or before sunrise. At such times, comets don’t sweep across the skies as meteors do. But they do move slowly, from night to night, in front of the stars. They can be very beautiful, especially in a dark sky.
View at EarthSky Community Photos. | Alan Howell of Greensboro, North Carolina, captured this image on September 4, 2023. He wrote: “3rd time is the charm! I was finally able to capture our newest comet, C/2023 P1 Nishimura, around 5:30 a.m. today just before the sunrise washed out the tail. What a spectacular sight to see this rare green beauty show up on my camera screen!” Thank you, Alan.
Recently, many enjoyed Comet A3 Tsuchinshan-ATLAS in the evening sky. When will the next bright comet appear? Only time will tell.
Bottom line: Comets are diffuse balls of ice and dust orbiting the sun. They’re sometimes visible in our skies. A comet’s tail may stretch millions of miles across space.
Comets are icy balls of gas, dust and rock that orbit the sun. Astronomers believe most comets are leftovers from the formation of the sun and planets. In fact, comets come from the farthest reaches of the solar system, including the Kuiper Belt and the Oort Cloud. When passing stars outside our solar system jostle comets, the comets begin the long trek inward toward the sun. Then, as they come close to the sun and heat up, they release gas in a process called outgassing. This creates the long, glowing tail that stretches behind the comet and points away from the sun.
The video above is from the Meet the Experts series of the European Space Agency (ESA). In it, comet scientist Charlotte Goetz, formerly of ESA, discusses comets, their formation and their study. Also, she explains that comet nuclei are relatively small – about the size of a small earthly town – and that they are loosely packed balls of ice and dust.
Moreover, the comets we know about are mostly potato-shaped, but some are more oddly shaped. In addition, it’s only when comets come near the sun that they heat up and spew dust and gases. In fact, they develop giant glowing heads – called a comet’s coma – that may be larger than most planets. And indeed, they sprout their long comet tails that stretch millions of miles long.
NASA says that the current number of known comets is 3,979.
The parts of a comet
The nucleus is the core of a comet. Additionally, it is also the head of the comet. When a comet nears the sun and heats up, some of its frozen surfaces begin to thaw and create the fuzzy coma that surrounds the nucleus.
Surprisingly, a comet can have two tails. The ion tail is generally bluish in color and points away from the sun because it’s blown back by the solar wind. The ion tail is made of – you guessed it – ions. These are electrically charged gas molecules. The second tail is the dust tail. It is indeed made of dust and normally has a whiter appearance. The dust tail forms a slightly curved trail behind the path of the comet.
Artist’s concept of the parts of a comet. Image via NASA.
Observing comets
Us skywatchers are, of course, most interested in comets when they appear as (sometimes unexpected, often greenish) visitors in our skies. Since comets are most active when they’re near the sun, we tend to see comets shortly after sunset or before sunrise. At such times, comets don’t sweep across the skies as meteors do. But they do move slowly, from night to night, in front of the stars. They can be very beautiful, especially in a dark sky.
View at EarthSky Community Photos. | Alan Howell of Greensboro, North Carolina, captured this image on September 4, 2023. He wrote: “3rd time is the charm! I was finally able to capture our newest comet, C/2023 P1 Nishimura, around 5:30 a.m. today just before the sunrise washed out the tail. What a spectacular sight to see this rare green beauty show up on my camera screen!” Thank you, Alan.
Recently, many enjoyed Comet A3 Tsuchinshan-ATLAS in the evening sky. When will the next bright comet appear? Only time will tell.
Bottom line: Comets are diffuse balls of ice and dust orbiting the sun. They’re sometimes visible in our skies. A comet’s tail may stretch millions of miles across space.
NASA’s Solar Dynamics Observatory (SDO) captured this image of a giant solar prominence on August 31, 2012. Although large and dramatic, it did not come close to having the power of a solar superstorm. Image via NASA/ SDO/ AIA/ Goddard Space Flight Center.
Scientists narrowed down the date of a solar superstorm that occurred more than 2,600 years ago to 664 BCE, based on a spike in carbon-14 in ancient tree rings.
The carbon-14 spike was found in ancient wood, including wood from an Iron Age child’s burial chamber in Russia.
This event was one of six solar superstorms that have occurred in the past 14,500 years, said the scientists.
About 2,600 years ago, ancient Assyrians witnessed a fiery red glow across the night sky. And they recorded this significant event on a stone tablet. We now know they saw bright auroras caused by a powerful solar storm. On November 20, 2024, scientists said they believe they’ve found evidence of this event in tree rings. Furthermore, they’ve pinpointed that it happened in 664 BCE, 2,688 years ago.
The researchers published their discovery in the peer-reviewed journal Communications Earth & Environment on August 23, 2024.
If a storm of that magnitude were to occur today, it would have a serious impact on our power and communications infrastructures. But it probably would not be catastrophic. Power grids and communications systems are growing increasingly resilient in weathering solar storms. To learn more, catch up with this informative interview with David Wallace, a professor of electrical engineering at Mississippi State University.
A closeup of tree rings, with the ring corresponding to 664 BCE labeled in the image. This wood came from a larch log at an archaeological site. It was part of a child’s burial chamber. Image via Irina Panyushkina. Used with permission.
Carbon-14 in tree rings reveal an extreme solar event
Irina Panyushkina at the University of Arizona led the team studying tree rings in ancient logs. In particular, they were measuring the amount of carbon-14 in the tree rings.
They discovered a much higher concentration of carbon-14 in rings that were formed in 664 BCE. This type of carbon-14 signature, in other studies, has been associated with solar superstorms.
What is carbon-14? It’s a type of radioactive carbon that forms continually in the atmosphere. Cosmic ray particles interact with nitrogen in the upper atmosphere to create carbon-14. Eventually, carbon-14 combines with oxygen to form carbon dioxide. Over a few months, that carbon dioxide containing carbon-14 makes its way to the lower atmosphere. There, trees take it up and store it in wood tissue.
During a solar superstorm, the sun releases enormous amounts of particles. These particles strike the Earth’s atmosphere, creating a much higher amount of carbon-14 than usual. As a result, trees alive during such an event absorb and store that additional carbon-14 in that year’s tree rings.
How often do solar superstorms occur?
Scientists have identified six solar superstorms – known as Miyake events – that have happened in the past 14,500 years. They occurred in 7176 BCE, 5410 BCE, 5259 BCE, around 660 BCE, 774 CE and 993 CE.
For all Miyake events, high carbon-14 spikes were found in tree rings of ancient wood corresponding to those dates. Also, scientists have found corroborating evidence in ancient ice core samples from Greenland and Antarctica. (Higher levels of beryllium-10 and chlorine-36, found in the ice, were a result of interactions between particles from the sun during the storm and the Earth’s atmosphere.)
However, there was uncertainty about the 660 BCE event. Scientists had known, from previous tree ring data and ice core studies, that a superstorm occurred around that time, but they did not know exactly when it happened. This new study narrowed the date to 664 BCE.
When will the next solar superstorm occur? Panyushkina said:
Tree rings give us an idea of the magnitude of these massive storms, but we can’t detect any type of pattern, so it is unlikely we’ll ever be able to predict when such an event is going to happen. Still, we believe our paper will transform how we search and understand the carbon-14 spike signal of extreme solar proton events in tree rings.
The energy from this type of event not only changes the atmosphere’s radiocarbon content but also the atmosphere’s chemistry. We are trying to figure out how those short-lived and powerful events affect the Earth system as a whole.
The wood that revealed the 664 BCE solar superstorm
The researchers used dead trees that lived a long time ago to study ancient tree rings. One of the wood samples came from a well-preserved tree from a riverbank at the Polar Urals, a mountain range in Russia.
Another was an archaeological timber from an ancient larch tree. Panyushkina told EarthSky more about it:
The archaeological wood is from a small child’s [burial] chamber made of larch logs from the highlands of the Altai Mountains. It belongs to the Pazyryk culture, associated with the Siberian Scythians. I worked on an archaeological project to date these burials, known as kurgans, in 2003. Local archaeologists from Novosibirsk [in Russia] excavated the cemetery, and I collected wood samples from the kurgans for dendrochronology and dating.
Researchers took a wood sample from this child’s burial chamber, made from larch logs. It was part of a kurgan, a type of burial mound associated with the Pazyryk culture of the Iron Age. Image via Irina Panyushkina. Used with permission.A cross-section of one of the logs from the burial chamber, showing the larch tree rings. Image via Irina Panyushkina. Used with permission.
Using tree rings to study past climate and to date events
Dendrochronology is the study of tree rings to date events and changes in the environment.
In temperate climates, where the seasons change, trees usually form annual rings. The size and density of each ring is determined by environmental conditions during that year. As a result, tree rings provide valuable insight into past climate in a particular region.
Tree rings can also be used for dating events. To do that, scientists build a long chronological timeline of ring patterns for a region, starting from living trees to progressively older dead trees. To date a tree ring sample, they compare the sample’s pattern to the reference chronological timeline, looking for a match. That match allows them to identify a date for their wood sample.
Bottom line: Scientists have narrowed down the date of a solar superstorm that occurred over 2,600 years ago to 664 BCE, based on a spike in carbon-14 in ancient tree rings.
NASA’s Solar Dynamics Observatory (SDO) captured this image of a giant solar prominence on August 31, 2012. Although large and dramatic, it did not come close to having the power of a solar superstorm. Image via NASA/ SDO/ AIA/ Goddard Space Flight Center.
Scientists narrowed down the date of a solar superstorm that occurred more than 2,600 years ago to 664 BCE, based on a spike in carbon-14 in ancient tree rings.
The carbon-14 spike was found in ancient wood, including wood from an Iron Age child’s burial chamber in Russia.
This event was one of six solar superstorms that have occurred in the past 14,500 years, said the scientists.
About 2,600 years ago, ancient Assyrians witnessed a fiery red glow across the night sky. And they recorded this significant event on a stone tablet. We now know they saw bright auroras caused by a powerful solar storm. On November 20, 2024, scientists said they believe they’ve found evidence of this event in tree rings. Furthermore, they’ve pinpointed that it happened in 664 BCE, 2,688 years ago.
The researchers published their discovery in the peer-reviewed journal Communications Earth & Environment on August 23, 2024.
If a storm of that magnitude were to occur today, it would have a serious impact on our power and communications infrastructures. But it probably would not be catastrophic. Power grids and communications systems are growing increasingly resilient in weathering solar storms. To learn more, catch up with this informative interview with David Wallace, a professor of electrical engineering at Mississippi State University.
A closeup of tree rings, with the ring corresponding to 664 BCE labeled in the image. This wood came from a larch log at an archaeological site. It was part of a child’s burial chamber. Image via Irina Panyushkina. Used with permission.
Carbon-14 in tree rings reveal an extreme solar event
Irina Panyushkina at the University of Arizona led the team studying tree rings in ancient logs. In particular, they were measuring the amount of carbon-14 in the tree rings.
They discovered a much higher concentration of carbon-14 in rings that were formed in 664 BCE. This type of carbon-14 signature, in other studies, has been associated with solar superstorms.
What is carbon-14? It’s a type of radioactive carbon that forms continually in the atmosphere. Cosmic ray particles interact with nitrogen in the upper atmosphere to create carbon-14. Eventually, carbon-14 combines with oxygen to form carbon dioxide. Over a few months, that carbon dioxide containing carbon-14 makes its way to the lower atmosphere. There, trees take it up and store it in wood tissue.
During a solar superstorm, the sun releases enormous amounts of particles. These particles strike the Earth’s atmosphere, creating a much higher amount of carbon-14 than usual. As a result, trees alive during such an event absorb and store that additional carbon-14 in that year’s tree rings.
How often do solar superstorms occur?
Scientists have identified six solar superstorms – known as Miyake events – that have happened in the past 14,500 years. They occurred in 7176 BCE, 5410 BCE, 5259 BCE, around 660 BCE, 774 CE and 993 CE.
For all Miyake events, high carbon-14 spikes were found in tree rings of ancient wood corresponding to those dates. Also, scientists have found corroborating evidence in ancient ice core samples from Greenland and Antarctica. (Higher levels of beryllium-10 and chlorine-36, found in the ice, were a result of interactions between particles from the sun during the storm and the Earth’s atmosphere.)
However, there was uncertainty about the 660 BCE event. Scientists had known, from previous tree ring data and ice core studies, that a superstorm occurred around that time, but they did not know exactly when it happened. This new study narrowed the date to 664 BCE.
When will the next solar superstorm occur? Panyushkina said:
Tree rings give us an idea of the magnitude of these massive storms, but we can’t detect any type of pattern, so it is unlikely we’ll ever be able to predict when such an event is going to happen. Still, we believe our paper will transform how we search and understand the carbon-14 spike signal of extreme solar proton events in tree rings.
The energy from this type of event not only changes the atmosphere’s radiocarbon content but also the atmosphere’s chemistry. We are trying to figure out how those short-lived and powerful events affect the Earth system as a whole.
The wood that revealed the 664 BCE solar superstorm
The researchers used dead trees that lived a long time ago to study ancient tree rings. One of the wood samples came from a well-preserved tree from a riverbank at the Polar Urals, a mountain range in Russia.
Another was an archaeological timber from an ancient larch tree. Panyushkina told EarthSky more about it:
The archaeological wood is from a small child’s [burial] chamber made of larch logs from the highlands of the Altai Mountains. It belongs to the Pazyryk culture, associated with the Siberian Scythians. I worked on an archaeological project to date these burials, known as kurgans, in 2003. Local archaeologists from Novosibirsk [in Russia] excavated the cemetery, and I collected wood samples from the kurgans for dendrochronology and dating.
Researchers took a wood sample from this child’s burial chamber, made from larch logs. It was part of a kurgan, a type of burial mound associated with the Pazyryk culture of the Iron Age. Image via Irina Panyushkina. Used with permission.A cross-section of one of the logs from the burial chamber, showing the larch tree rings. Image via Irina Panyushkina. Used with permission.
Using tree rings to study past climate and to date events
Dendrochronology is the study of tree rings to date events and changes in the environment.
In temperate climates, where the seasons change, trees usually form annual rings. The size and density of each ring is determined by environmental conditions during that year. As a result, tree rings provide valuable insight into past climate in a particular region.
Tree rings can also be used for dating events. To do that, scientists build a long chronological timeline of ring patterns for a region, starting from living trees to progressively older dead trees. To date a tree ring sample, they compare the sample’s pattern to the reference chronological timeline, looking for a match. That match allows them to identify a date for their wood sample.
Bottom line: Scientists have narrowed down the date of a solar superstorm that occurred over 2,600 years ago to 664 BCE, based on a spike in carbon-14 in ancient tree rings.
The constellation Tucana the Toucan is visible year-round from Earth’s Southern Hemisphere. That’s because it’s near the south celestial pole, the point in the sky around which all southern stars revolve. So those of us in the Northern Hemisphere would have to travel southward on Earth’s globe to see Tucana. And, once we got there, we’d find that the stars of this constellation aren’t particularly bright or remarkable. Yet many of us know Tucana by name. Why?
It’s because this constellation is famous for being home to the Small Magellanic Cloud, the fuzzy patch in the sky that represents one of two relatively large dwarf galaxies orbiting our Milky Way. Plus, southern stargazers know that a large globular star cluster – 47 Tucanae, visible to the unaided eye – is also located within the boundaries of Tucana. In fact, this constellation’s stars are harder to pick out than the globular cluster and galaxy that anchor its southern edge.
On the opposite side of the constellation from Alpha is Beta Tucanae, a star system containing six stars loosely bound together. Beta 1 is the brightest and shines at magnitude 4.36. Beta 2 shines at magnitude 4.53, and Beta 3 shines at 5.07. The whole Beta Tucanae system is an average of 140 light-years from Earth.
You’ll find the Small Magellanic Cloud in the southeast corner of the constellation Tucana. The nearby bright star is Achernar, across the border in the constellation Eridanus the River. Chart by IAU. Used with permission.
Small Magellanic Cloud
Despite its great distance of 197,000 light-years, the Small Magellanic Cloud is one of the closest galaxies to Earth. You can see it without optical aid as a misty, cloudy patch from dark-sky locations. The Small Magellanic Cloud is an irregular galaxy but has a central bar as part of its structure, making it look like a disturbed former spiral. It’s the smaller of the two satellite galaxies in the Southern Hemisphere skies, with the larger being the aptly named the Large Magellanic Cloud.
The Small Magellanic Cloud has many clusters and nebulae within its expanse. An excellent target for a telescope, clusters stream through its length and out one tail. The Small Magellanic Cloud’s nearby kin, the Large Magellanic Cloud, lies in the constellations Mensa and Dorado. Both of these nearby galaxies are being sucked inward by our Milky Way Galaxy and will eventually be absorbed by it.
The Small Magellanic Cloud galaxy is a striking feature of the southern sky, but visible-light telescopes cannot get a clear view. Like the “cloud” in its name, the satellite galaxy also harbors obscuring dust clouds. The Visible and Infrared Survey Telescope for Astronomy (VISTA) allows a clearer view of the Small Magellanic Cloud. Notice also globular cluster 47 Tucanae to the right of the galaxy. Image via ESO/ VISTA VMC.View larger. | Can you spot Tucana the Toucan in this image of the night sky over the ALMA telescopes in Chile? The Small Magellanic Cloud lies within the border of Tucana. The bright ball of light to the upper right of the Small Magellanic Cloud is the globular cluster 47 Tucanae. Imagine the Toucan standing with its feet on the Small Magellanic Cloud. Image via ESO/ C. Malin.
47 Tucanae
The globular cluster 47 Tucanae also bears the catalog name NGC 104. It shines bright at magnitude 4.0 and is easily visible with the unaided eye. In excellent seeing conditions, it appears as large as the full moon. It’s the second brightest globular cluster of the Milky Way and contains millions of stars. Use binoculars or a telescope to resolve thousands of stars in the cluster.
47 Tucanae lies 14,500 light-years away. 47 Tucanae and the Small Magellanic Cloud may look close together, but that is only a line-of-sight coincidence. The Small Magellanic Cloud is about 14 times farther away.
The Southern Hemisphere’s 47 Tucanae is the second brightest globular cluster in the sky as viewed from Earth. Millions of stars create this cluster. Image via NASA/ ESA/ the Hubble Heritage/ Wikimedia Commons.
Bonus globular cluster
Want a bonus observing target? On the opposite edge of the Small Magellanic Cloud’s curving shape from 47 Tucanae is NGC 362, another bright globular cluster. NGC 362 is a bit dimmer than 47 Tucanae, at magnitude 6.4, but still a good target in binoculars or small telescopes.
The globular cluster NGC 362 appears on the outskirts of the Small Magellanic Cloud. NGC 362 orbits the Milky Way in a highly eccentric orbit. Image via NASA/ JPL-Caltech/ University of Virginia/ R. Schiavon/ Wikimedia Commons.
The Hubble Deep Field South
The Hubble Space Telescope took a series of famous images called “deep fields” starting in the 1990s. In these images, the space telescope stared at what mostly looks like a blank area of sky for a long period of time, allowing the faint background objects to come to light. One of these images, the Hubble Deep Field South, came from a region of Tucana.
View larger. | The red circle shows the location of the Hubble Deep Field South in the southern constellation of Tucana the Toucan. All the stars on this chart are visible to the unaided eye on a dark, clear night. Image via ESO.View larger. | This image – Hubble Deep Field South – from the NASA/ESA Hubble Space Telescope is one of the first deepest visible/ultraviolet light images of the universe. The Hubble Space Telescope captured a tiny region of Tucana the Toucan in this image. Take some time to admire the huge array of galaxies in the deepest depths of space and from the early years of the universe. Image via R. Williams and the HDF-S team/ ESO.
Bottom line: Tucana the Toucan is a constellation in the Southern Hemisphere that’s a cinch to spot. Just look for our little satellite galaxy, the Small Magellanic Cloud. Two easy-to-observe globular clusters also reside here.
The constellation Tucana the Toucan is visible year-round from Earth’s Southern Hemisphere. That’s because it’s near the south celestial pole, the point in the sky around which all southern stars revolve. So those of us in the Northern Hemisphere would have to travel southward on Earth’s globe to see Tucana. And, once we got there, we’d find that the stars of this constellation aren’t particularly bright or remarkable. Yet many of us know Tucana by name. Why?
It’s because this constellation is famous for being home to the Small Magellanic Cloud, the fuzzy patch in the sky that represents one of two relatively large dwarf galaxies orbiting our Milky Way. Plus, southern stargazers know that a large globular star cluster – 47 Tucanae, visible to the unaided eye – is also located within the boundaries of Tucana. In fact, this constellation’s stars are harder to pick out than the globular cluster and galaxy that anchor its southern edge.
On the opposite side of the constellation from Alpha is Beta Tucanae, a star system containing six stars loosely bound together. Beta 1 is the brightest and shines at magnitude 4.36. Beta 2 shines at magnitude 4.53, and Beta 3 shines at 5.07. The whole Beta Tucanae system is an average of 140 light-years from Earth.
You’ll find the Small Magellanic Cloud in the southeast corner of the constellation Tucana. The nearby bright star is Achernar, across the border in the constellation Eridanus the River. Chart by IAU. Used with permission.
Small Magellanic Cloud
Despite its great distance of 197,000 light-years, the Small Magellanic Cloud is one of the closest galaxies to Earth. You can see it without optical aid as a misty, cloudy patch from dark-sky locations. The Small Magellanic Cloud is an irregular galaxy but has a central bar as part of its structure, making it look like a disturbed former spiral. It’s the smaller of the two satellite galaxies in the Southern Hemisphere skies, with the larger being the aptly named the Large Magellanic Cloud.
The Small Magellanic Cloud has many clusters and nebulae within its expanse. An excellent target for a telescope, clusters stream through its length and out one tail. The Small Magellanic Cloud’s nearby kin, the Large Magellanic Cloud, lies in the constellations Mensa and Dorado. Both of these nearby galaxies are being sucked inward by our Milky Way Galaxy and will eventually be absorbed by it.
The Small Magellanic Cloud galaxy is a striking feature of the southern sky, but visible-light telescopes cannot get a clear view. Like the “cloud” in its name, the satellite galaxy also harbors obscuring dust clouds. The Visible and Infrared Survey Telescope for Astronomy (VISTA) allows a clearer view of the Small Magellanic Cloud. Notice also globular cluster 47 Tucanae to the right of the galaxy. Image via ESO/ VISTA VMC.View larger. | Can you spot Tucana the Toucan in this image of the night sky over the ALMA telescopes in Chile? The Small Magellanic Cloud lies within the border of Tucana. The bright ball of light to the upper right of the Small Magellanic Cloud is the globular cluster 47 Tucanae. Imagine the Toucan standing with its feet on the Small Magellanic Cloud. Image via ESO/ C. Malin.
47 Tucanae
The globular cluster 47 Tucanae also bears the catalog name NGC 104. It shines bright at magnitude 4.0 and is easily visible with the unaided eye. In excellent seeing conditions, it appears as large as the full moon. It’s the second brightest globular cluster of the Milky Way and contains millions of stars. Use binoculars or a telescope to resolve thousands of stars in the cluster.
47 Tucanae lies 14,500 light-years away. 47 Tucanae and the Small Magellanic Cloud may look close together, but that is only a line-of-sight coincidence. The Small Magellanic Cloud is about 14 times farther away.
The Southern Hemisphere’s 47 Tucanae is the second brightest globular cluster in the sky as viewed from Earth. Millions of stars create this cluster. Image via NASA/ ESA/ the Hubble Heritage/ Wikimedia Commons.
Bonus globular cluster
Want a bonus observing target? On the opposite edge of the Small Magellanic Cloud’s curving shape from 47 Tucanae is NGC 362, another bright globular cluster. NGC 362 is a bit dimmer than 47 Tucanae, at magnitude 6.4, but still a good target in binoculars or small telescopes.
The globular cluster NGC 362 appears on the outskirts of the Small Magellanic Cloud. NGC 362 orbits the Milky Way in a highly eccentric orbit. Image via NASA/ JPL-Caltech/ University of Virginia/ R. Schiavon/ Wikimedia Commons.
The Hubble Deep Field South
The Hubble Space Telescope took a series of famous images called “deep fields” starting in the 1990s. In these images, the space telescope stared at what mostly looks like a blank area of sky for a long period of time, allowing the faint background objects to come to light. One of these images, the Hubble Deep Field South, came from a region of Tucana.
View larger. | The red circle shows the location of the Hubble Deep Field South in the southern constellation of Tucana the Toucan. All the stars on this chart are visible to the unaided eye on a dark, clear night. Image via ESO.View larger. | This image – Hubble Deep Field South – from the NASA/ESA Hubble Space Telescope is one of the first deepest visible/ultraviolet light images of the universe. The Hubble Space Telescope captured a tiny region of Tucana the Toucan in this image. Take some time to admire the huge array of galaxies in the deepest depths of space and from the early years of the universe. Image via R. Williams and the HDF-S team/ ESO.
Bottom line: Tucana the Toucan is a constellation in the Southern Hemisphere that’s a cinch to spot. Just look for our little satellite galaxy, the Small Magellanic Cloud. Two easy-to-observe globular clusters also reside here.
After a successful launch on November 19, 2024, the Starship Flight 6 test mission from Starbase in southern Texas headed toward the Caribbean, then to South Africa, before ending its mission in the Indian Ocean.
About 12 minutes after launch, people in Puerto Rico took videos of the eye-catching flyby. But there was a surprise: Many observers reported that they were able to hear a low-frequency rumble while Starship was visible.
Not too loud, but detectable. In fact, observers across the Caribbean island reported the same sound.
In some videos, skywatchers commented: “I can hear the rocket,” while other observers confirmed they could also clearly hear sounds from Starship.
SpaceX Starship launched toward space from Texas on November 19, 2024. Image via SpaceX.
When you look at high-flying aircraft, the sound usually seems to come from the area of the sky where the object was a few moments ago. The sound lags, because sound travels slower than the photons of light that let us see the aircraft. The same is true for lightning and thunder. We see the flash before we hear the rumble, unless the lightning is quite close by.
But with Starship, there was no delay in the low-frequency sound: Observers felt the rumble coming from the same direction of the rocket, which, in theory, should not occur because light travels faster than sound. In this case, you are looking at an object that is moving at speeds between 15,000 and 17,500 miles per hour.
So, how is this possible? The answer is electrophonic sounds.
What are electrophonic sounds?
Electrophonic sounds occur when electromagnetic energy – or waves from light and heat – interact with the ionosphere, and the waves propagate through the atmosphere at the speed of light.
This strange audible effect was first used to explain how some rare meteors can produce a hiss or low-frequency sound that can be heard in real time or with no delay, as you are seeing a meteor.
When these fast-moving waves reach Earth’s surface, objects such as trees, structures or nearby walls behave like passive speakers or acoustic reflectors, allowing observers to hear the low-frequency sounds. Studies show that even long hair, hats and sunglasses can improve someone’s ability to hear these low-frequency sounds.
On January 27, 2000, the Molniya 1-67 satellite reentered the atmosphere over western Australia, and research confirmed electrophonic sound reports, which means the audible effect is not exclusive to meteors.
Meanwhile, Starship appears to be the first rocket that can also produce the curious, real-time sound effect.
The rocket passed over a meteor camera in Puerto Rico (and thus passed by its centrally located microphone). You can slightly hear the low-frequency sounds or rumble starting around 06:12:36 on this video. (According to the time stamp at upper right.)
Bottom line: The powerful SpaceX Starship rocket emitted electrophonic sounds that observers in Puerto Rico heard as it passed overhead on November 19, 2024.
After a successful launch on November 19, 2024, the Starship Flight 6 test mission from Starbase in southern Texas headed toward the Caribbean, then to South Africa, before ending its mission in the Indian Ocean.
About 12 minutes after launch, people in Puerto Rico took videos of the eye-catching flyby. But there was a surprise: Many observers reported that they were able to hear a low-frequency rumble while Starship was visible.
Not too loud, but detectable. In fact, observers across the Caribbean island reported the same sound.
In some videos, skywatchers commented: “I can hear the rocket,” while other observers confirmed they could also clearly hear sounds from Starship.
SpaceX Starship launched toward space from Texas on November 19, 2024. Image via SpaceX.
When you look at high-flying aircraft, the sound usually seems to come from the area of the sky where the object was a few moments ago. The sound lags, because sound travels slower than the photons of light that let us see the aircraft. The same is true for lightning and thunder. We see the flash before we hear the rumble, unless the lightning is quite close by.
But with Starship, there was no delay in the low-frequency sound: Observers felt the rumble coming from the same direction of the rocket, which, in theory, should not occur because light travels faster than sound. In this case, you are looking at an object that is moving at speeds between 15,000 and 17,500 miles per hour.
So, how is this possible? The answer is electrophonic sounds.
What are electrophonic sounds?
Electrophonic sounds occur when electromagnetic energy – or waves from light and heat – interact with the ionosphere, and the waves propagate through the atmosphere at the speed of light.
This strange audible effect was first used to explain how some rare meteors can produce a hiss or low-frequency sound that can be heard in real time or with no delay, as you are seeing a meteor.
When these fast-moving waves reach Earth’s surface, objects such as trees, structures or nearby walls behave like passive speakers or acoustic reflectors, allowing observers to hear the low-frequency sounds. Studies show that even long hair, hats and sunglasses can improve someone’s ability to hear these low-frequency sounds.
On January 27, 2000, the Molniya 1-67 satellite reentered the atmosphere over western Australia, and research confirmed electrophonic sound reports, which means the audible effect is not exclusive to meteors.
Meanwhile, Starship appears to be the first rocket that can also produce the curious, real-time sound effect.
The rocket passed over a meteor camera in Puerto Rico (and thus passed by its centrally located microphone). You can slightly hear the low-frequency sounds or rumble starting around 06:12:36 on this video. (According to the time stamp at upper right.)
Bottom line: The powerful SpaceX Starship rocket emitted electrophonic sounds that observers in Puerto Rico heard as it passed overhead on November 19, 2024.
The Webb Space Telescope took this new image of the Sombrero Galaxy (M104), which ESA and NASA released on November 26, 2024. Image via NASA/ ESA/ CSA/ STScI.
The Sombrero Galaxy in infrared
The James Webb Space Telescope, which explores the universe in infrared light, has a new view of an old favorite: the Sombrero Galaxy. ESA and NASA released this image of the Sombrero Galaxy (M104) – which lies 30 million light-years from Earth in the constellation Virgo – on November 26, 2024. Webb’s Mid-Infrared Instrument (MIRI) lets us see past the blinding brightness and the finer dust to the inner core region and speckles of stars. Webb, like Hubble, sees dust in the outer ring, but reveals how it is distributed in intricate clumps.
The Sombrero Galaxy is not a place of especially active star formation. And the supermassive black hole at the galaxy’s core – what astronomers call an active galactic nucleus, or AGN – is, despite its mass, what ESA calls “rather docile.”
The Sombrero Galaxy produces less than one solar mass of stars per year. The Milky Way’s star production is about twice that high, but both galaxies have mostly already converted their gas and dust into stars. Compare that to the starburst galaxy M82, which sees 10 to 20 times more stars born per year than the Milky Way and Sombrero.
The supermassive black hole at the center of the Sombrero Galaxy has the mass of about 9 billion solar masses. This is on the heavier end, as far as supermassive black holes go. And the Sombrero is home to some 2,000 globular clusters, or massive balls of stars held together in a spherical clump by their own gravity.
This is the Hubble space telescope image of M104, or the Sombrero Galaxy. Compare this view to the infrared image from Webb above. Image via ESA/ Hubblesite/ Wikimedia Commons (public domain).
See it for yourself
The Sombrero Galaxy is located on the southeastern border of Virgo the Maiden near the constellation Corvus the Crow. Without a doubt, M104 is a stunning galaxy in photographs. Even better, at magnitude 8.3, you can see it in small telescopes. It’s an edge-on, dusty spiral galaxy with a bright core.
What you get for
$1,000,
$1,000,000,000
and
$10,000,000,000
The Webb Space Telescope took this new image of the Sombrero Galaxy (M104), which ESA and NASA released on November 26, 2024. Image via NASA/ ESA/ CSA/ STScI.
The Sombrero Galaxy in infrared
The James Webb Space Telescope, which explores the universe in infrared light, has a new view of an old favorite: the Sombrero Galaxy. ESA and NASA released this image of the Sombrero Galaxy (M104) – which lies 30 million light-years from Earth in the constellation Virgo – on November 26, 2024. Webb’s Mid-Infrared Instrument (MIRI) lets us see past the blinding brightness and the finer dust to the inner core region and speckles of stars. Webb, like Hubble, sees dust in the outer ring, but reveals how it is distributed in intricate clumps.
The Sombrero Galaxy is not a place of especially active star formation. And the supermassive black hole at the galaxy’s core – what astronomers call an active galactic nucleus, or AGN – is, despite its mass, what ESA calls “rather docile.”
The Sombrero Galaxy produces less than one solar mass of stars per year. The Milky Way’s star production is about twice that high, but both galaxies have mostly already converted their gas and dust into stars. Compare that to the starburst galaxy M82, which sees 10 to 20 times more stars born per year than the Milky Way and Sombrero.
The supermassive black hole at the center of the Sombrero Galaxy has the mass of about 9 billion solar masses. This is on the heavier end, as far as supermassive black holes go. And the Sombrero is home to some 2,000 globular clusters, or massive balls of stars held together in a spherical clump by their own gravity.
This is the Hubble space telescope image of M104, or the Sombrero Galaxy. Compare this view to the infrared image from Webb above. Image via ESA/ Hubblesite/ Wikimedia Commons (public domain).
See it for yourself
The Sombrero Galaxy is located on the southeastern border of Virgo the Maiden near the constellation Corvus the Crow. Without a doubt, M104 is a stunning galaxy in photographs. Even better, at magnitude 8.3, you can see it in small telescopes. It’s an edge-on, dusty spiral galaxy with a bright core.
What you get for
$1,000,
$1,000,000,000
and
$10,000,000,000
Artist’s concept of NASA’s Europa Clipper shows the spacecraft silhouetted against Europa’s surface, with the magnetometer boom fully deployed at top and the antennas for the radar instrument extending out from the solar arrays. Image via NASA/ JPL-Caltech.
UPDATE, November 26, 2024. Six weeks after its October 14 launch, NASA’s Europa Clipper is already 13 million miles (20 million km) from Earth. It’s travelling at 22 miles per second (35 kilometers per second) relative to the sun, and will soon gain more speed when it completes a gravity assist around Mars in March 2025.
Deployment and testing of Clipper’s instruments is underway and going smoothly. Clipper deployed its basketball court-sized solar arrays shortly after launch. And it followed this by uncoiling the 28-foot-long (8.5-meter-long) boom that holds the craft’s magnetometer. This instrument will measure Europa’s magnetic field, which should confirm the presence of an ocean beneath the moon’s crust and tell scientists how deep and salty it is.
Most recently, Clipper deployed several antennas for its radar instrument, which it will use to study the thickness and structure of Europa’s icy crust, among other tasks. These antennas and the magnetometer boom will remain deployed for the next decade, at attention through Clipper’s journey to Jupiter and the mission itself. The remaining seven instruments on the spacecraft will be powered on and off over the next two months so engineers can check they’re in working order.
Europa Clipper is NASA’s mission to explore one of Jupiter’s four large Galilean satellites. The moon Europa has an icy outer crust that covers an ocean world. It holds twice as much water as Earth’s oceans. So, scientists want to know more about the habitability – the ability for some form of live to exist – on this large moon.
To get Europa Clipper from Earth to Jupiter in about 5 1/2 years, the trajectory has to take advantage of flybys in the solar system. Therefore, the mission had to launch between October 10 and November 5, 2024, due to planetary alignments. The first date, October 10, became a no-go after Hurricane Milton appeared on the scene, threatening Florida.
But Europa Clipper launched successfully from Kennedy Space Center on October 14, and is now cruising on its 6-year, 1.8 billion-mile (2.9 billion km) journey to Jupiter, where it will arrive in April 2030.
Europa Clipper is NASA’s largest planetary exploration spacecraft yet. The solar sails are 100 feet (30 meters) tall. And at launch, the spacecraft weighed as much as an African elephant.
Watch a video about Europa Clipper.
What will the mission do?
Europa Clipper carries nine instruments. Some of the instruments will look down at the moon and record what it observes, while others will sample the environment the spacecraft passes through. The space around Europa is bathed with intense radiation from Jupiter. But this region may also have plumes of water erupting from under the moon’s icy crust.
To protect the spacecraft, Europa Clipper will be orbiting Jupiter and not the moon itself. The spacecraft will only dip into Europa’s environment during close flybys. The spacecraft will make 49 flybys, one every two to three weeks of its mission. Europa Clipper will get as close as 16 miles (25 km) from the moon’s surface.
The mission’s three main science objectives are to understand the nature of the ice shell and the ocean beneath it, along with the moon’s composition and geology. The mission’s detailed exploration of Europa will help scientists better understand the astrobiological potential for habitable worlds beyond our planet.
View larger. | Artist’s concept of Europa Clipper sweeping past Europa, one of the large, fascinating moons of giant Jupiter. Image via NASA/ JPL-Caltech.
Could Europa be habitable?
Could life exist in the oceans of Europa under the layers of ice? That’s what scientists want to know. Plus, how is there liquid water under ice in such a cold place? James O’Donoghue of the University of Reading wrote for The Conversation:
The water in Europa’s ocean is kept liquid due to frictional heating. This heating occurs because Europa becomes stretched and then relaxed as it interacts with Jupiter’s gravity on its orbital path around the giant planet. For Europa’s ocean to be habitable, a steady supply of ingredients is needed to allow some form of chemosynthesis to take place.
If these ingredients exist, they could come from hydrothermal vents on Europa’s rocky seafloor, like those on Earth, or from material seeping down through the icy crust, the ‘sea ceiling’ if you like. We do not yet know if these mechanisms are plausible, so we need more data from many different angles.
There is growing evidence that plumes of material are escaping from Europa’s surface into space. If this material is from the ocean, measuring its composition would give us insights into the habitability of that ocean.
Artist’s concept (not to scale) showing a cutaway of Europa’s interior. At top is the outer icy shell with plumes, then an ocean of liquid water and finally a rocky interior with possible hydrothermal vents on the seafloor. Image via NASA/ JPL-Caltech.
Bottom line: Europa Clipper is on its way to explore the icy ocean moon of Jupiter. Deployment and testing of its instruments is underway and going smoothly.
Artist’s concept of NASA’s Europa Clipper shows the spacecraft silhouetted against Europa’s surface, with the magnetometer boom fully deployed at top and the antennas for the radar instrument extending out from the solar arrays. Image via NASA/ JPL-Caltech.
UPDATE, November 26, 2024. Six weeks after its October 14 launch, NASA’s Europa Clipper is already 13 million miles (20 million km) from Earth. It’s travelling at 22 miles per second (35 kilometers per second) relative to the sun, and will soon gain more speed when it completes a gravity assist around Mars in March 2025.
Deployment and testing of Clipper’s instruments is underway and going smoothly. Clipper deployed its basketball court-sized solar arrays shortly after launch. And it followed this by uncoiling the 28-foot-long (8.5-meter-long) boom that holds the craft’s magnetometer. This instrument will measure Europa’s magnetic field, which should confirm the presence of an ocean beneath the moon’s crust and tell scientists how deep and salty it is.
Most recently, Clipper deployed several antennas for its radar instrument, which it will use to study the thickness and structure of Europa’s icy crust, among other tasks. These antennas and the magnetometer boom will remain deployed for the next decade, at attention through Clipper’s journey to Jupiter and the mission itself. The remaining seven instruments on the spacecraft will be powered on and off over the next two months so engineers can check they’re in working order.
Europa Clipper is NASA’s mission to explore one of Jupiter’s four large Galilean satellites. The moon Europa has an icy outer crust that covers an ocean world. It holds twice as much water as Earth’s oceans. So, scientists want to know more about the habitability – the ability for some form of live to exist – on this large moon.
To get Europa Clipper from Earth to Jupiter in about 5 1/2 years, the trajectory has to take advantage of flybys in the solar system. Therefore, the mission had to launch between October 10 and November 5, 2024, due to planetary alignments. The first date, October 10, became a no-go after Hurricane Milton appeared on the scene, threatening Florida.
But Europa Clipper launched successfully from Kennedy Space Center on October 14, and is now cruising on its 6-year, 1.8 billion-mile (2.9 billion km) journey to Jupiter, where it will arrive in April 2030.
Europa Clipper is NASA’s largest planetary exploration spacecraft yet. The solar sails are 100 feet (30 meters) tall. And at launch, the spacecraft weighed as much as an African elephant.
Watch a video about Europa Clipper.
What will the mission do?
Europa Clipper carries nine instruments. Some of the instruments will look down at the moon and record what it observes, while others will sample the environment the spacecraft passes through. The space around Europa is bathed with intense radiation from Jupiter. But this region may also have plumes of water erupting from under the moon’s icy crust.
To protect the spacecraft, Europa Clipper will be orbiting Jupiter and not the moon itself. The spacecraft will only dip into Europa’s environment during close flybys. The spacecraft will make 49 flybys, one every two to three weeks of its mission. Europa Clipper will get as close as 16 miles (25 km) from the moon’s surface.
The mission’s three main science objectives are to understand the nature of the ice shell and the ocean beneath it, along with the moon’s composition and geology. The mission’s detailed exploration of Europa will help scientists better understand the astrobiological potential for habitable worlds beyond our planet.
View larger. | Artist’s concept of Europa Clipper sweeping past Europa, one of the large, fascinating moons of giant Jupiter. Image via NASA/ JPL-Caltech.
Could Europa be habitable?
Could life exist in the oceans of Europa under the layers of ice? That’s what scientists want to know. Plus, how is there liquid water under ice in such a cold place? James O’Donoghue of the University of Reading wrote for The Conversation:
The water in Europa’s ocean is kept liquid due to frictional heating. This heating occurs because Europa becomes stretched and then relaxed as it interacts with Jupiter’s gravity on its orbital path around the giant planet. For Europa’s ocean to be habitable, a steady supply of ingredients is needed to allow some form of chemosynthesis to take place.
If these ingredients exist, they could come from hydrothermal vents on Europa’s rocky seafloor, like those on Earth, or from material seeping down through the icy crust, the ‘sea ceiling’ if you like. We do not yet know if these mechanisms are plausible, so we need more data from many different angles.
There is growing evidence that plumes of material are escaping from Europa’s surface into space. If this material is from the ocean, measuring its composition would give us insights into the habitability of that ocean.
Artist’s concept (not to scale) showing a cutaway of Europa’s interior. At top is the outer icy shell with plumes, then an ocean of liquid water and finally a rocky interior with possible hydrothermal vents on the seafloor. Image via NASA/ JPL-Caltech.
Bottom line: Europa Clipper is on its way to explore the icy ocean moon of Jupiter. Deployment and testing of its instruments is underway and going smoothly.
The Journal of Geophysical Research: Atmospheres published new research on November 21, 2024, that’s bad news for the Middle East and North Africa. Some of these areas could experience a rapid temperature rise of up to 9 degrees Celsius (16 F) this century. Pictured here is Riyadh, a city in an inland region of Saudi Arabia. Image via Stijn te Strake/ Unsplash.
Some of the hottest countries in the world are in North Africa and the Middle East.
These countries have already exceeded the 1.5-degree-Celsius warming limit, as outlined in the Paris agreement. But parts of the Middle East and North Africa have already exceeded 1.5 and 2 degrees Celsius.
These regions could experience even warmer temperatures, perhaps a rise of up to 9 degrees Celsius (16 F), in this century. That’s according to a new study published November 21, 2024.
The Middle East and North Africa, which already include some of the hottest and driest spots on Earth, are undergoing accelerated climate change and will reach warming thresholds two to three decades earlier than the rest of the world. That’s according to a new study published on November 21, 2024, in the Journal of Geophysical Research: Atmospheres. By 2100, parts of the Arabian Peninsula could experience up to 9 degrees Celsius (16.2 F) of warming.
The region, which already has record-breaking summer temperatures, is currently close to exceeding 2 degrees Celsius (3.6 F) of warming on average compared to preindustrial temperatures. Additional warming in the region could make some areas uninhabitable without adaptation measures.
Abdul Malik, a climate scientist at King Abdullah University of Science and Technology and the study’s lead author, said:
When we talk about the Paris Agreement, we say that we should try to limit global warming to 1.5 degrees Celsius [2.7 F], and that we should not exceed 2 degrees Celsius [3.6 F]. But in parts of the Middle East and North Africa, warming has already surpassed 1.5 and 2 degrees Celsius.
Why is 1.5 degrees Celsius the target?
Why do we compare temperatures now to the preindustrial level? This is the level discussed in the Paris Agreement. In the Paris Agreement, 196 parties agreed to limit temperature increases to well below 2 C above preindustrial levels and to aim for 1.5 C. So why is 2 C the magic number? As Maria Ivanova at Northeastern University explained:
At 2 degrees we see dramatic alterations to the ability of the Earth’s system to maintain the conditions that allow for human life and indeed other species’ life.
Modeling a rapidly warming region
The Middle East and North Africa are predominantly desert ecosystems. Most of the population lives in coastal areas. Predictions from previous climate models have both over- and under-estimated warming in the region. So a more nuanced understanding of warming across the region has eluded scientists.
In this study, the researchers used CMIP5 and CMIP6 models to analyze the Middle East and North Africa at high spatial resolution (81 square kilometers, or approximately 30 square miles) and understand warming in the region in more detail. Malik said:
Although previous studies have shown that the region is warming much faster than other areas, we have shown that the warming rate is not consistent across the region. And this warming rate could vary between 1.5 to 3.5 times faster than the global average.
The rapid rate means that the Middle East and North Africa could reach 3 and 4 degrees Celsius of warming (5.4 and 7.2 F) nearly three decades earlier than most of the globe. That warming will be especially rapid in inland areas of the Arabian Peninsula.
The Middle East and North Africa already include some of the hottest countries on the planet. Hotspots will grow over inland Saudi Arabia, Mauritania, Iran’s Elburz Mountains and Algeria. That’s according to new research in the Journal of Geophysical Research: Atmospheres. Video via Abdul Malik.
A hot region gets hotter
The Middle East and North Africa include some of the hottest regions on the planet … and the researchers predict continued dramatic warming. The central Arabian Peninsula is already warming up to three times faster than the rest of the world, the study found. That rate is on par with warming in the Arctic.
By 2100, the Arabian Peninsula could warm on average by 2.6 degrees Celsius (4.7 F) under low emission scenarios, and by 7.6 degrees Celsius (13.7 F) under high emission scenarios.
That’s because the Middle East and North Africa’s dry deserts can’t easily cool down through soil moisture evaporation. In contrast, their humid equatorial counterparts elsewhere on the globe do have this ability.
Georgiy Stenchikov, a retired climate scientist and one of the study’s co-authors, said:
Desert regions warm almost as fast as polar regions, and they have much higher temperatures. So the temperature threshold is reached much faster than in polar regions.
Because of coastal cooling, heavily populated areas along the southern and west coasts of the Arabian Peninsula, including Oman, are not currently warming as fast as inland areas and the peninsula’s east coast.
Warming rates are not consistent across the seasons. The researchers found summer hotspots over the central Arabian Peninsula, including the populous Riyadh Province, and Algeria; and winter hotspots over Mauritania and Iran’s Elburz Mountains.
Adapting to a rapid temperature rise
If the world meets low-emissions targets, the rate of warming in the Middle East and North Africa could slow by up to 38%. Individual cities could also try to adapt to the extreme heat through urban greening and architectural solutions. Stenchikov said:
Adaptation will be necessary, and these adaptation measures could be tested and developed in the Middle East and North Africa. Global warming is a global problem, so you cannot prevent it in just one place. But you can develop artificial environments in regions with high populations.
Bottom line: A new study predicts that inland areas of North Africa and the Middle East could experience a rapid temperature rise of up to 9 degrees Celsius (16 F) in the coming years.
The Journal of Geophysical Research: Atmospheres published new research on November 21, 2024, that’s bad news for the Middle East and North Africa. Some of these areas could experience a rapid temperature rise of up to 9 degrees Celsius (16 F) this century. Pictured here is Riyadh, a city in an inland region of Saudi Arabia. Image via Stijn te Strake/ Unsplash.
Some of the hottest countries in the world are in North Africa and the Middle East.
These countries have already exceeded the 1.5-degree-Celsius warming limit, as outlined in the Paris agreement. But parts of the Middle East and North Africa have already exceeded 1.5 and 2 degrees Celsius.
These regions could experience even warmer temperatures, perhaps a rise of up to 9 degrees Celsius (16 F), in this century. That’s according to a new study published November 21, 2024.
The Middle East and North Africa, which already include some of the hottest and driest spots on Earth, are undergoing accelerated climate change and will reach warming thresholds two to three decades earlier than the rest of the world. That’s according to a new study published on November 21, 2024, in the Journal of Geophysical Research: Atmospheres. By 2100, parts of the Arabian Peninsula could experience up to 9 degrees Celsius (16.2 F) of warming.
The region, which already has record-breaking summer temperatures, is currently close to exceeding 2 degrees Celsius (3.6 F) of warming on average compared to preindustrial temperatures. Additional warming in the region could make some areas uninhabitable without adaptation measures.
Abdul Malik, a climate scientist at King Abdullah University of Science and Technology and the study’s lead author, said:
When we talk about the Paris Agreement, we say that we should try to limit global warming to 1.5 degrees Celsius [2.7 F], and that we should not exceed 2 degrees Celsius [3.6 F]. But in parts of the Middle East and North Africa, warming has already surpassed 1.5 and 2 degrees Celsius.
Why is 1.5 degrees Celsius the target?
Why do we compare temperatures now to the preindustrial level? This is the level discussed in the Paris Agreement. In the Paris Agreement, 196 parties agreed to limit temperature increases to well below 2 C above preindustrial levels and to aim for 1.5 C. So why is 2 C the magic number? As Maria Ivanova at Northeastern University explained:
At 2 degrees we see dramatic alterations to the ability of the Earth’s system to maintain the conditions that allow for human life and indeed other species’ life.
Modeling a rapidly warming region
The Middle East and North Africa are predominantly desert ecosystems. Most of the population lives in coastal areas. Predictions from previous climate models have both over- and under-estimated warming in the region. So a more nuanced understanding of warming across the region has eluded scientists.
In this study, the researchers used CMIP5 and CMIP6 models to analyze the Middle East and North Africa at high spatial resolution (81 square kilometers, or approximately 30 square miles) and understand warming in the region in more detail. Malik said:
Although previous studies have shown that the region is warming much faster than other areas, we have shown that the warming rate is not consistent across the region. And this warming rate could vary between 1.5 to 3.5 times faster than the global average.
The rapid rate means that the Middle East and North Africa could reach 3 and 4 degrees Celsius of warming (5.4 and 7.2 F) nearly three decades earlier than most of the globe. That warming will be especially rapid in inland areas of the Arabian Peninsula.
The Middle East and North Africa already include some of the hottest countries on the planet. Hotspots will grow over inland Saudi Arabia, Mauritania, Iran’s Elburz Mountains and Algeria. That’s according to new research in the Journal of Geophysical Research: Atmospheres. Video via Abdul Malik.
A hot region gets hotter
The Middle East and North Africa include some of the hottest regions on the planet … and the researchers predict continued dramatic warming. The central Arabian Peninsula is already warming up to three times faster than the rest of the world, the study found. That rate is on par with warming in the Arctic.
By 2100, the Arabian Peninsula could warm on average by 2.6 degrees Celsius (4.7 F) under low emission scenarios, and by 7.6 degrees Celsius (13.7 F) under high emission scenarios.
That’s because the Middle East and North Africa’s dry deserts can’t easily cool down through soil moisture evaporation. In contrast, their humid equatorial counterparts elsewhere on the globe do have this ability.
Georgiy Stenchikov, a retired climate scientist and one of the study’s co-authors, said:
Desert regions warm almost as fast as polar regions, and they have much higher temperatures. So the temperature threshold is reached much faster than in polar regions.
Because of coastal cooling, heavily populated areas along the southern and west coasts of the Arabian Peninsula, including Oman, are not currently warming as fast as inland areas and the peninsula’s east coast.
Warming rates are not consistent across the seasons. The researchers found summer hotspots over the central Arabian Peninsula, including the populous Riyadh Province, and Algeria; and winter hotspots over Mauritania and Iran’s Elburz Mountains.
Adapting to a rapid temperature rise
If the world meets low-emissions targets, the rate of warming in the Middle East and North Africa could slow by up to 38%. Individual cities could also try to adapt to the extreme heat through urban greening and architectural solutions. Stenchikov said:
Adaptation will be necessary, and these adaptation measures could be tested and developed in the Middle East and North Africa. Global warming is a global problem, so you cannot prevent it in just one place. But you can develop artificial environments in regions with high populations.
Bottom line: A new study predicts that inland areas of North Africa and the Middle East could experience a rapid temperature rise of up to 9 degrees Celsius (16 F) in the coming years.
