Did you see our LIVESTREAM on Monday, October 14, 2024? We talked about extreme weather events with climatologist Davide Faranda!
Extreme weather LIVE chat with Davide Faranda
On Monday, October 14, we talked about dangerous and sometimes deadly weather extremes. We sat down with climatologist Davide Faranda. He’s the research director for climate physics at the French Laboratoire de Science du Climat et de l’Environnement. And he’s an expert on cold spells, heatwaves, cyclones and severe thunderstorms.
Faranda’s expertise focuses on how extreme weather events may be linked to overall warming on Earth. He wants to understand how much greenhouse gases influence the occurrence of these extremes. And he demonstrates event-by-event findings at the website ClimaMeter.org.
Davide Faranda is the research director in climate physics in the Laboratoire de Science du Climat et de l’Environnement (LSCE) of the Institut Pierre-Simon Laplace at the French National Center for Scientific Research (CNRS). At LSCE, Davide coordinates the group ESTIMR, which works at understanding climate extremes from a statistical and dynamical point of view. He is also an external fellow of the London Mathematical Laboratory, and of the Laboratoire de Météorologie Dynamique de l’École Normale Supérieure in Paris. Image via Davide Faranda.
Did you see our LIVESTREAM on Monday, October 14, 2024? We talked about extreme weather events with climatologist Davide Faranda!
Extreme weather LIVE chat with Davide Faranda
On Monday, October 14, we talked about dangerous and sometimes deadly weather extremes. We sat down with climatologist Davide Faranda. He’s the research director for climate physics at the French Laboratoire de Science du Climat et de l’Environnement. And he’s an expert on cold spells, heatwaves, cyclones and severe thunderstorms.
Faranda’s expertise focuses on how extreme weather events may be linked to overall warming on Earth. He wants to understand how much greenhouse gases influence the occurrence of these extremes. And he demonstrates event-by-event findings at the website ClimaMeter.org.
Davide Faranda is the research director in climate physics in the Laboratoire de Science du Climat et de l’Environnement (LSCE) of the Institut Pierre-Simon Laplace at the French National Center for Scientific Research (CNRS). At LSCE, Davide coordinates the group ESTIMR, which works at understanding climate extremes from a statistical and dynamical point of view. He is also an external fellow of the London Mathematical Laboratory, and of the Laboratoire de Météorologie Dynamique de l’École Normale Supérieure in Paris. Image via Davide Faranda.
View larger and annotated. Yarelis Medina caught the anti-tail of Comet A3 on October 13, 2024, from Utuado, Puerto Rico.
C/2023 A3 (Tsuchinshan–ATLAS) is currently visible in the evening sky, and it has a rare anti-tail pointing towards the sun.
An anti-tail is sometimes called an illusion. But it’s real and appears when, as on October 13-15, Earth is crossing the comet’s orbital plane.
The anti-tail reveals the comet’s past path, or where it has already traveled through space. It’s different from the dust tail, which is created by solar radiation pressure and the solar wind and always points away from the sun.
Comet A3 has an anti-tail!
Comet A3 is becoming easier to spot with the unaided eye, as it moves up and away from the sunset point this week. Try to spot the comet after sunset this week, facing west. The comet was closest to Earth on Saturday, October 12, so this week might be the best time to spot it. Long-exposure (10- to 45-second) images are also showing a faint, downwards or sun directed tail, which is called the anti-tail.
The anti-tail is often said to be an optical illusion, because it appears in the opposite direction of the comet’s dust tail. But it is, in fact, a real phenomenon, visible only when Earth is crossing the comet’s orbital plane.
And we have been passing the comet’s orbital plane since yesterday (October 13), and will keep crossing it on October 14 and 15. Long-exposure images of Comet A3 taken on the last few nights are showing this faint but interesting detail of the comet. It happens because the space geometry – or relative positions of the Earth, the comet and the sun – lets us see sunlight on larger particles left behind by the comet in its orbit. From our perspective, these cometary particles are being lit by the sun from behind.
Meanwhile, the main or brighter tail that we see is caused by the dust and lighter particles being blown away by the intense heat from the sun.
Another image of A3’s anti-tail, from Rincon, Puerto Rico. Image via Victor Rivera.
The anti-tail: A possible meteor shower producer?
Although casual observers might be confused and might think the material in the dust tail shows us the comet’s trajectory through space, we should keep in mind that the main dust tail shows its materials (light dust particles and ices sublimated by the sun’s heat) are being blown by the pressure of solar radiation and the solar wind. Hence, a comet’s dust tail always points away from the sun, a fact you can see for yourself as you stand watching this comet in the western sky after sunset.
Meanwhile, the faint downwards anti-tail is showing us where the comet was coming from. Sunlight coming from behind is revealing the comet’s previous trajectory – its orbit – and also shows where the larger particles are being left in the comet’s orbit. These larger particles are the ones that can cause bright meteors if Earth ever were to cross the path of those particles in the future.
A possible meteor shower in the future?
It’s fascinating that this week we can be looking at a possible meteor-producing comet tail. Will we see them? So far, calculations don’t indicate that Earth will cross through those particles’ path. So … no meteors from Comet A3 (that we know of, yet)!
Also, an effect that might be seen this week is a possible slight increase in the comet’s brightness. That’s somewhat surprising, because Earth and the comet have already passed their closest point, so the comet is getting farther away from now. Still, it might look a bit brighter to us now, as Earth crosses the comet’s orbital plane, and as all the dust particles (both light and larger particles) appear more concentrated as seen from Earth.
Bottom line: Comet A3 and Earth have passed their closest point. But, early this week, we’re crossing the plane of the comet’s orbit. Some are seeing an anti-tail!
Read more: Want to see Comet A3? It’s back! West after sunset
View larger and annotated. Yarelis Medina caught the anti-tail of Comet A3 on October 13, 2024, from Utuado, Puerto Rico.
C/2023 A3 (Tsuchinshan–ATLAS) is currently visible in the evening sky, and it has a rare anti-tail pointing towards the sun.
An anti-tail is sometimes called an illusion. But it’s real and appears when, as on October 13-15, Earth is crossing the comet’s orbital plane.
The anti-tail reveals the comet’s past path, or where it has already traveled through space. It’s different from the dust tail, which is created by solar radiation pressure and the solar wind and always points away from the sun.
Comet A3 has an anti-tail!
Comet A3 is becoming easier to spot with the unaided eye, as it moves up and away from the sunset point this week. Try to spot the comet after sunset this week, facing west. The comet was closest to Earth on Saturday, October 12, so this week might be the best time to spot it. Long-exposure (10- to 45-second) images are also showing a faint, downwards or sun directed tail, which is called the anti-tail.
The anti-tail is often said to be an optical illusion, because it appears in the opposite direction of the comet’s dust tail. But it is, in fact, a real phenomenon, visible only when Earth is crossing the comet’s orbital plane.
And we have been passing the comet’s orbital plane since yesterday (October 13), and will keep crossing it on October 14 and 15. Long-exposure images of Comet A3 taken on the last few nights are showing this faint but interesting detail of the comet. It happens because the space geometry – or relative positions of the Earth, the comet and the sun – lets us see sunlight on larger particles left behind by the comet in its orbit. From our perspective, these cometary particles are being lit by the sun from behind.
Meanwhile, the main or brighter tail that we see is caused by the dust and lighter particles being blown away by the intense heat from the sun.
Another image of A3’s anti-tail, from Rincon, Puerto Rico. Image via Victor Rivera.
The anti-tail: A possible meteor shower producer?
Although casual observers might be confused and might think the material in the dust tail shows us the comet’s trajectory through space, we should keep in mind that the main dust tail shows its materials (light dust particles and ices sublimated by the sun’s heat) are being blown by the pressure of solar radiation and the solar wind. Hence, a comet’s dust tail always points away from the sun, a fact you can see for yourself as you stand watching this comet in the western sky after sunset.
Meanwhile, the faint downwards anti-tail is showing us where the comet was coming from. Sunlight coming from behind is revealing the comet’s previous trajectory – its orbit – and also shows where the larger particles are being left in the comet’s orbit. These larger particles are the ones that can cause bright meteors if Earth ever were to cross the path of those particles in the future.
A possible meteor shower in the future?
It’s fascinating that this week we can be looking at a possible meteor-producing comet tail. Will we see them? So far, calculations don’t indicate that Earth will cross through those particles’ path. So … no meteors from Comet A3 (that we know of, yet)!
Also, an effect that might be seen this week is a possible slight increase in the comet’s brightness. That’s somewhat surprising, because Earth and the comet have already passed their closest point, so the comet is getting farther away from now. Still, it might look a bit brighter to us now, as Earth crosses the comet’s orbital plane, and as all the dust particles (both light and larger particles) appear more concentrated as seen from Earth.
Bottom line: Comet A3 and Earth have passed their closest point. But, early this week, we’re crossing the plane of the comet’s orbit. Some are seeing an anti-tail!
Read more: Want to see Comet A3? It’s back! West after sunset
View larger. | Moon-orbiting spacecraft from various nations confirmed the presence of water ice at the moon’s poles in the early 2000s. The deposits of water ice lie in deep, permanently shadowed moon craters. Now new data from NASA’s Lunar Reconnaissance Orbiter (LRO) suggests that ice on the moon is even more widespread than we thought. Image via NASA/ GSFC/ Arizona State University.
We know there’s water ice in deep, shadowed craters, near the moon’s poles. The ice remains frozen due to the lack of sunlight and extreme cold.
There’s even more ice on the moon than we knew previously, according to a new NASA study. The evidence comes from data obtained by NASA’s Lunar Reconnaissance Orbiter.
There are various theories to explain the origin of the ice, including impacts from comets or meteors, interior gas or chemical reactions.
The moon is an extremely dry place compared to Earth. There are no rivers or lakes, not even puddles. There are, however, water molecules bound in the regolith, and ice deposits, primarily near the South Pole. But now, a new study by NASA scientists shows that ice deposits are widespread and more extensive than first thought. The researchers said on October 3, 2024, that new analysis of data from NASA’s Lunar Reconnaissance Orbiter (LRO) revealed the additional deposits.
The researchers published their peer-reviewed findings in The Planetary Science Journal on October 2, 2024.
Ice on the moon more widespread than thought
Scientists already knew there were ice deposits in permanently shadowed regions (PSRs) in craters near the South Pole. But the new study reveals ice deposits well outside of that region.
Timothy McClanahan at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of the study. He said:
We find that there is widespread evidence of water ice within PSRs outside the South Pole, towards at least 77 degrees south latitude. Our model and analysis show that greatest ice concentrations are expected to occur near the PSRs’ coldest locations below 75 Kelvin (-198°C or -325°F) and near the base of the PSRs’ poleward-facing slopes.
The researchers don’t know yet exactly how much ice there is or how deep it may be buried. McClanahan continued:
We can’t accurately determine the volume of the PSRs’ ice deposits or identify if they might be buried under a dry layer of regolith. However, we expect that for each surface 1.2 square yards (1 square meter) residing over these deposits there should be at least about five more quarts (five more liters) of ice within the surface top 3.3 feet (1 meter), as compared to their surrounding areas.
View larger. | This map shows the distribution of permanently shadowed regions (PSRs), in blue, around the lunar South Pole. The PSRs reach up to about 80 degrees south latitude. The elevation map is from Lunar Orbiter Laser Altimeter instrument on NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft. Image via NASA/ GSFC/ Timothy P. McClanahan.
Lunar Reconnaissance Orbiter reveals ice deposits
How did the researchers find the ice deposits? They used data from instruments on NASA’s Lunar Reconnaissance Orbiter (LRO). In particular, the Lunar Exploration Neutron Detector (LEND) instrument and LEND’s Collimated Sensor for Epithermal Neutrons (CSETN). The instruments measured moderate-energy or “epithermal” neutrons on the lunar surface. Neutrons originate from intense, high-energy cosmic rays, which come from cosmic events such as exploding stars. Along with protons, they make up the nucleus of every atom except ordinary hydrogen. Eventually, some of the cosmic rays impact the moon. They break up the already existing atoms in the regolith and create subatomic neutrons.
The neutrons can collide with other atoms in the regolith. As a result, some of them will be ejected out into space. LEND can then easily detect them, since there is virtually no atmosphere on the moon.
How does that help find the ice? The water in the ice is made of hydrogen atoms. And hydrogen atoms have a similar mass to neutrons. So when a neutron collides with a hydrogen atom, the neutron loses more energy than it would from colliding with most other atoms. That tells scientists the atom it collided with was a hydrogen atom. Which means water, frozen as ice since it can’t be liquid.
How did the ice get there?
Since the moon has no other liquid water and no atmosphere to speak of, how did the ice get there? There are three main possibilities. One is that it is delivered by comet or meteor impacts. Another is that it originates as gas from the interior of the moon itself that freezes on the surface. Chemical reactions between hydrogen in the solar wind and oxygen in the lunar regolith could also produce the ice.
The ice can persist for billions of years because it is in the permanently shadowed regions (PSRs) of deep craters near the poles. So the ice never sees any sunlight, and therefore the PSRs are also extremely cold. In such regions, there might even be enough ice for future astronauts to mine.
The findings are good news for the prospect of human settlement on the moon in the future. The ice, melted as water, could be used not only for drinking, but also to make rocket fuel, energy and breathable air. It could even be used to help protect from radiation.
Bottom line: A new NASA study of permanently shadowed regions near the lunar South Pole shows that there is a lot more water ice on the moon than previously thought.
View larger. | Moon-orbiting spacecraft from various nations confirmed the presence of water ice at the moon’s poles in the early 2000s. The deposits of water ice lie in deep, permanently shadowed moon craters. Now new data from NASA’s Lunar Reconnaissance Orbiter (LRO) suggests that ice on the moon is even more widespread than we thought. Image via NASA/ GSFC/ Arizona State University.
We know there’s water ice in deep, shadowed craters, near the moon’s poles. The ice remains frozen due to the lack of sunlight and extreme cold.
There’s even more ice on the moon than we knew previously, according to a new NASA study. The evidence comes from data obtained by NASA’s Lunar Reconnaissance Orbiter.
There are various theories to explain the origin of the ice, including impacts from comets or meteors, interior gas or chemical reactions.
The moon is an extremely dry place compared to Earth. There are no rivers or lakes, not even puddles. There are, however, water molecules bound in the regolith, and ice deposits, primarily near the South Pole. But now, a new study by NASA scientists shows that ice deposits are widespread and more extensive than first thought. The researchers said on October 3, 2024, that new analysis of data from NASA’s Lunar Reconnaissance Orbiter (LRO) revealed the additional deposits.
The researchers published their peer-reviewed findings in The Planetary Science Journal on October 2, 2024.
Ice on the moon more widespread than thought
Scientists already knew there were ice deposits in permanently shadowed regions (PSRs) in craters near the South Pole. But the new study reveals ice deposits well outside of that region.
Timothy McClanahan at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of the study. He said:
We find that there is widespread evidence of water ice within PSRs outside the South Pole, towards at least 77 degrees south latitude. Our model and analysis show that greatest ice concentrations are expected to occur near the PSRs’ coldest locations below 75 Kelvin (-198°C or -325°F) and near the base of the PSRs’ poleward-facing slopes.
The researchers don’t know yet exactly how much ice there is or how deep it may be buried. McClanahan continued:
We can’t accurately determine the volume of the PSRs’ ice deposits or identify if they might be buried under a dry layer of regolith. However, we expect that for each surface 1.2 square yards (1 square meter) residing over these deposits there should be at least about five more quarts (five more liters) of ice within the surface top 3.3 feet (1 meter), as compared to their surrounding areas.
View larger. | This map shows the distribution of permanently shadowed regions (PSRs), in blue, around the lunar South Pole. The PSRs reach up to about 80 degrees south latitude. The elevation map is from Lunar Orbiter Laser Altimeter instrument on NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft. Image via NASA/ GSFC/ Timothy P. McClanahan.
Lunar Reconnaissance Orbiter reveals ice deposits
How did the researchers find the ice deposits? They used data from instruments on NASA’s Lunar Reconnaissance Orbiter (LRO). In particular, the Lunar Exploration Neutron Detector (LEND) instrument and LEND’s Collimated Sensor for Epithermal Neutrons (CSETN). The instruments measured moderate-energy or “epithermal” neutrons on the lunar surface. Neutrons originate from intense, high-energy cosmic rays, which come from cosmic events such as exploding stars. Along with protons, they make up the nucleus of every atom except ordinary hydrogen. Eventually, some of the cosmic rays impact the moon. They break up the already existing atoms in the regolith and create subatomic neutrons.
The neutrons can collide with other atoms in the regolith. As a result, some of them will be ejected out into space. LEND can then easily detect them, since there is virtually no atmosphere on the moon.
How does that help find the ice? The water in the ice is made of hydrogen atoms. And hydrogen atoms have a similar mass to neutrons. So when a neutron collides with a hydrogen atom, the neutron loses more energy than it would from colliding with most other atoms. That tells scientists the atom it collided with was a hydrogen atom. Which means water, frozen as ice since it can’t be liquid.
How did the ice get there?
Since the moon has no other liquid water and no atmosphere to speak of, how did the ice get there? There are three main possibilities. One is that it is delivered by comet or meteor impacts. Another is that it originates as gas from the interior of the moon itself that freezes on the surface. Chemical reactions between hydrogen in the solar wind and oxygen in the lunar regolith could also produce the ice.
The ice can persist for billions of years because it is in the permanently shadowed regions (PSRs) of deep craters near the poles. So the ice never sees any sunlight, and therefore the PSRs are also extremely cold. In such regions, there might even be enough ice for future astronauts to mine.
The findings are good news for the prospect of human settlement on the moon in the future. The ice, melted as water, could be used not only for drinking, but also to make rocket fuel, energy and breathable air. It could even be used to help protect from radiation.
Bottom line: A new NASA study of permanently shadowed regions near the lunar South Pole shows that there is a lot more water ice on the moon than previously thought.
Snails are quite common creatures. Surely, you’ve seen one in person or even held one with your own fingers … or hands, because some are huge. There are many curious facts about snails. Did you know that there are land, sea and freshwater snails? We’re going to focus on land snails. Snails are hermaphrodites, which means they are both male and female at the same time. Furthermore, land snails are able to move on the blade of a knife without cutting themselves. And they have thousands of teeth.
Snails have tentacles
Snails are gastropod mollusks. That is, they are invertebrate animals: They do not have bones or joints. Their bodies can be divided into three parts: head, shell and foot.
Snails have tentacles. The four little horns on their heads are flexible and move in all directions. The top two have eyes at the ends, although they can only distinguish changes in light intensity, as if to differentiate day from night. The two little horns below are sensory organs that snails use to feel the terrain and guide themselves. Snails have their sense of smell in all four tentacles.
Additionally, snails are deaf, as they do not have ear canals. So, to look for food, they use their sense of smell and their tentacles. Likewise, snails can retract and regenerate their tentacles if they lose them. Another fascinating fact is that snails can remember the places they have been and the objects in their environment.
And land snails breathe through lungs. There is a hole on the side of the body, under the shell, that communicates with the lung. But some species that live in areas with a lot of humidity can breathe via gills.
The 4 little horns on snails’ heads are flexible and move in all directions. Snails use them to see, smell and feel the terrain and guide themselves. Image via Marinko Krsmanovic/ Pexels.
Who owns the coolest houses?
Imagine a house that you can take everywhere, protects you and is also beautiful? Well, yes, snails are lucky. And so are you, if you have a van.
Snails have shells made of calcium carbonate. Their organs are well protected under it, so when they feel threatened, they hide the rest of the body inside.
Additionally, when environmental conditions become harsh, snails can crawl into their shells and seal them to “hibernate” for as long as necessary. In reality, this process is known as estivating, which is entering a state of lethargy or inactivity to survive unfavorable conditions such as drought, extreme cold or lack of food.
During estivation, snails seal themselves inside their shells and reduce their metabolism to conserve energy and water. The length of the estivation period can vary depending on environmental conditions and the species of snail. But, in general, snails can estivate for weeks, months and even years before returning to activity when conditions improve.
It is not surprising these incredible animals inhabited the planet about 550 million years ago, back in the Cambrian period.
And, thanks to its shell, you can know the approximate age of a snail. You just have to analyze the number of spirals it has. Another curious fact is that the shell of snails complies with the laws of the Fibonacci sequence. A Fibonacci sequence is a mathematical sequence in which each number is the sum of the two preceding numbers.
Snails’ shells are used for protection. These animals can even spend months inside them when environmental conditions become harsh. Image via Ragib Huda/ Unsplash.
Snail slime, the best defense
The third part of the snail is a single foot, called the ventral (belly) foot. To move, the muscles of the foot contract and create wave movements. The foot requires a large production of mucus to facilitate movement on rocks, sand or grass.
Furthermore, that layer of slime is not only abundant, but also dense. It’s so dense it prevents even the sharpest blades from touching the snail’s delicate skin.
In addition, the mucus they produce serves to create a protective barrier at the entrance to their shells and seal them, to prevent them from dehydrating in places where there is little humidity or high temperatures. It also helps them communicate with other snails using chemical signals.
As you can see, although they are generally tiny creatures, snails are resistant and strong. They can even carry 10 times their own weight.
Snails have a single foot they use to move. Its muscles contract and create waves. Also, they produce a mucus to help them move and protect their skin. Image via Alexia Francois/ Unsplash.
Not all snails are small
There are 35,000 species of land snails worldwide. Normally, you think of snails as small creatures. But they aren’t all small. For example, the giant African snail can measure up to a foot (30 cm).
Normally, snails are small, like the one here, but there are enormous ones! Like the Giant African land snail. Image via Pixabay/ Pexels.
Snails are hermaphrodites
In the snail kingdom there are no kings or queens, neither males nor females. Snails are hermaphrodites, that is, they have a female and male reproductive system at the same time. Now, they cannot self-fertilize, so they have to mate with another snail to exchange genetic material and fertilize their eggs.
Snails can produce at least 50 eggs in one clutch. And, by the way, the shell of their eggs is also made of calcium carbonate. After 15 days the baby snails are ready to hatch.
A common snail lives up to 7 years on average.
Snails are hermaphrodites, that is, they have both a female and male reproductive system. Image via Riadh Dallel/ Pexels.
How many teeth?!
Land snails are herbivores and love to eat plants, vegetables and fruits, although there are some carnivorous species that feed on worms and even dead animals. And there are cannibal snails! Some species of land snails eat other snails.
These animals can have up to 25,000 tiny teeth in their mouths. The teeth are found in rows in a structure called the radula, with which they scrape their food, rather than chew it, and then swallow it.
Believe it or not, these tiny animals have 25,000 teeth in their mouths. Plus, they scrape their food, rather than chew it. Image via Julian/ Unsplash.
How slow is a snail?
Snails have a well-deserved reputation for being slow. They can travel at a relative speed of one meter (yard) per hour. Humans travel that distance with one stride.
Are they really that slow? Well, yes. But they are very agile and can stick to many different surfaces. Image via Daniyal Ghanavati/ Pexels.
More photos
“Want a ride? Jump on, I’m strong.” Snails can carry 10 times their own weight. Image via Krzysztof Niewolny/ Unsplash.What a cool house! You can take it anywhere. Image via Ankur Dutta/ Unsplash.There are 35,000 species of land snails worldwide. Image via Haci Elmas/ Unsplash.Snails can produce at least 50 eggs in one clutch. Image via Raquel Raclette/ Unsplash.
Bottom line: There are many surprising facts about land snails. Did you know a snail is both male and female? And they can have 25,000 teeth?
Snails are quite common creatures. Surely, you’ve seen one in person or even held one with your own fingers … or hands, because some are huge. There are many curious facts about snails. Did you know that there are land, sea and freshwater snails? We’re going to focus on land snails. Snails are hermaphrodites, which means they are both male and female at the same time. Furthermore, land snails are able to move on the blade of a knife without cutting themselves. And they have thousands of teeth.
Snails have tentacles
Snails are gastropod mollusks. That is, they are invertebrate animals: They do not have bones or joints. Their bodies can be divided into three parts: head, shell and foot.
Snails have tentacles. The four little horns on their heads are flexible and move in all directions. The top two have eyes at the ends, although they can only distinguish changes in light intensity, as if to differentiate day from night. The two little horns below are sensory organs that snails use to feel the terrain and guide themselves. Snails have their sense of smell in all four tentacles.
Additionally, snails are deaf, as they do not have ear canals. So, to look for food, they use their sense of smell and their tentacles. Likewise, snails can retract and regenerate their tentacles if they lose them. Another fascinating fact is that snails can remember the places they have been and the objects in their environment.
And land snails breathe through lungs. There is a hole on the side of the body, under the shell, that communicates with the lung. But some species that live in areas with a lot of humidity can breathe via gills.
The 4 little horns on snails’ heads are flexible and move in all directions. Snails use them to see, smell and feel the terrain and guide themselves. Image via Marinko Krsmanovic/ Pexels.
Who owns the coolest houses?
Imagine a house that you can take everywhere, protects you and is also beautiful? Well, yes, snails are lucky. And so are you, if you have a van.
Snails have shells made of calcium carbonate. Their organs are well protected under it, so when they feel threatened, they hide the rest of the body inside.
Additionally, when environmental conditions become harsh, snails can crawl into their shells and seal them to “hibernate” for as long as necessary. In reality, this process is known as estivating, which is entering a state of lethargy or inactivity to survive unfavorable conditions such as drought, extreme cold or lack of food.
During estivation, snails seal themselves inside their shells and reduce their metabolism to conserve energy and water. The length of the estivation period can vary depending on environmental conditions and the species of snail. But, in general, snails can estivate for weeks, months and even years before returning to activity when conditions improve.
It is not surprising these incredible animals inhabited the planet about 550 million years ago, back in the Cambrian period.
And, thanks to its shell, you can know the approximate age of a snail. You just have to analyze the number of spirals it has. Another curious fact is that the shell of snails complies with the laws of the Fibonacci sequence. A Fibonacci sequence is a mathematical sequence in which each number is the sum of the two preceding numbers.
Snails’ shells are used for protection. These animals can even spend months inside them when environmental conditions become harsh. Image via Ragib Huda/ Unsplash.
Snail slime, the best defense
The third part of the snail is a single foot, called the ventral (belly) foot. To move, the muscles of the foot contract and create wave movements. The foot requires a large production of mucus to facilitate movement on rocks, sand or grass.
Furthermore, that layer of slime is not only abundant, but also dense. It’s so dense it prevents even the sharpest blades from touching the snail’s delicate skin.
In addition, the mucus they produce serves to create a protective barrier at the entrance to their shells and seal them, to prevent them from dehydrating in places where there is little humidity or high temperatures. It also helps them communicate with other snails using chemical signals.
As you can see, although they are generally tiny creatures, snails are resistant and strong. They can even carry 10 times their own weight.
Snails have a single foot they use to move. Its muscles contract and create waves. Also, they produce a mucus to help them move and protect their skin. Image via Alexia Francois/ Unsplash.
Not all snails are small
There are 35,000 species of land snails worldwide. Normally, you think of snails as small creatures. But they aren’t all small. For example, the giant African snail can measure up to a foot (30 cm).
Normally, snails are small, like the one here, but there are enormous ones! Like the Giant African land snail. Image via Pixabay/ Pexels.
Snails are hermaphrodites
In the snail kingdom there are no kings or queens, neither males nor females. Snails are hermaphrodites, that is, they have a female and male reproductive system at the same time. Now, they cannot self-fertilize, so they have to mate with another snail to exchange genetic material and fertilize their eggs.
Snails can produce at least 50 eggs in one clutch. And, by the way, the shell of their eggs is also made of calcium carbonate. After 15 days the baby snails are ready to hatch.
A common snail lives up to 7 years on average.
Snails are hermaphrodites, that is, they have both a female and male reproductive system. Image via Riadh Dallel/ Pexels.
How many teeth?!
Land snails are herbivores and love to eat plants, vegetables and fruits, although there are some carnivorous species that feed on worms and even dead animals. And there are cannibal snails! Some species of land snails eat other snails.
These animals can have up to 25,000 tiny teeth in their mouths. The teeth are found in rows in a structure called the radula, with which they scrape their food, rather than chew it, and then swallow it.
Believe it or not, these tiny animals have 25,000 teeth in their mouths. Plus, they scrape their food, rather than chew it. Image via Julian/ Unsplash.
How slow is a snail?
Snails have a well-deserved reputation for being slow. They can travel at a relative speed of one meter (yard) per hour. Humans travel that distance with one stride.
Are they really that slow? Well, yes. But they are very agile and can stick to many different surfaces. Image via Daniyal Ghanavati/ Pexels.
More photos
“Want a ride? Jump on, I’m strong.” Snails can carry 10 times their own weight. Image via Krzysztof Niewolny/ Unsplash.What a cool house! You can take it anywhere. Image via Ankur Dutta/ Unsplash.There are 35,000 species of land snails worldwide. Image via Haci Elmas/ Unsplash.Snails can produce at least 50 eggs in one clutch. Image via Raquel Raclette/ Unsplash.
Bottom line: There are many surprising facts about land snails. Did you know a snail is both male and female? And they can have 25,000 teeth?
The October 17 full moon is the Super Hunter’s Moon. It’s the 3rd of 4 supermoons in a row in 2024. It’ll rise in the east opposite the sunset, be highest in the sky around midnight and set in the west around sunrise. Chart via EarthSky.
It’s a full moon, the Hunter’s Moon and the closest supermoon of 2024.
Super Hunter’s Moon follows the Super Harvest Moon
When and where to look in 2024: For all of us on Earth, the bright, round full moon will rise in the east around sunset on October 17, 2024. It’ll be visible all night. Be sure to watch on the nights before and after that, too. This is the Northern Hemisphere’s Hunter’s Moon, the full moon after the Harvest Moon (which is the full moon closest to the autumnal equinox). This Hunter’s Moon is also the third of four supermoons in a row in 2024. The crest of the full moon falls that morning for the Americas at 11:26 UTC on October 17. That’s 6:26 a.m. CDT, about two hours before moonset in central North America. If you want to see the fullest possible moon, look in the west on the morning of October 17 before sunrise. The moon’s perigee, or closest point to Earth for this month, falls about 10 hours before the crest of the moon’s full phase. Perigee comes at 8 p.m. CDT on October 16 (1 UTC on October 17). So this is a very close full moon, known as a supermoon. In fact, it’s the closest supermoon of 2024! So it’ll be the brightest moon of this year. Characteristics of the Hunter’s Moon: The moon is always roundest on the day that it’s full. And, on the day of a full moon, the moon always rises close to the time of sunset. But the nights before and after a full moon feature a round-looking moon, too. And, like the Harvest Moon, this October Hunter’s moon will be characterized by a shorter-than-usual time between successive moonrises for several nights in a row. So Northern Hemisphere dwellers will see full-looking moons in twilight skies, ascending in the east as the sun sets in the west, for several nights around October 17. For the Southern Hemisphere, the nights around this full moon feature a longer-than-usual time between successive moonrises. So, for the southern part of the globe, the moon will rise on October 18, 19 and 20 (and for many nights after that) in a sky that’s already dark.
At full moon, the sun, Earth and moon are aligned in space, with Earth in the middle. The moon’s day side – its fully lighted hemisphere – directly faces us. Chart via EarthSky.
What’s special about a Hunter’s Moon?
A full moon is always opposite the sun in space, and opposite the sun in our sky. So all full moons rise in the east around sunset. And all full moons set in the west around sunrise. But the various full moons have different characteristics.
On average, the moon rises about 50 minutes later each day. But when a full moon happens close to the autumnal equinox – either a Harvest or a Hunter’s Moon – the moon (at mid-temperate latitudes) rises only about 30 to 35 minutes later daily for several days before and after the full moon. The reason is that the ecliptic – which more or less marks the path the moon travels across the sky – makes a narrow angle with the evening horizon around the time of the autumnal equinox.
The result is that there’s a shorter-than-usual lag time between successive moonrises around the full Hunter’s Moon.
Early evening moonrises make every Hunter’s Moon special. Every full moon rises around sunset. After the full Hunter’s Moon, you’ll see the moon ascending in the east relatively soon after sunset for a few days in a row at northerly latitudes.
A great source of moonrise times is the Custom Sunrise Sunset Calendar. Once you get to that page, be sure to click the box for “moon phases” and “moonrise and moonset times.”
By the way, since the Harvest Moon is the closest full moon to the equinox, it can come either before or after it. So the Harvest Moon can sometimes fall in October, which it does every three or four years. When the Harvest Moon falls in October, the Hunter’s Moon – the full moon following the Harvest Moon – will fall in early November.
That’ll happen next in 2025.
When the angle of the ecliptic is narrow, the moon rises noticeably farther north on your horizon from one night to the next. So there’s no long period of darkness between sunset and moonrise. In other words, around the time of an autumn full moon, many people see the rising moon ascending in the eastern sky in twilight for several evenings in a row. If you’re in the Southern Hemisphere, your evening ecliptic is nearly perpendicular to your early evening horizon now. You’ll see the full moon rise in twilight, but the next night’s moon comes up in darkness, much later at night. Image via ClassicalAstronomy.com. Used with permission.
A word about supermoons
A full supermoon happens when the full moon happens at – or near – the time the moon is closest to us in its elliptical orbit.
Of course, full supermoons draw a lot of attention and are very popular.
Do supermoons look bigger to the eye? Generally not, unless you’re an avid moon observer. But … do supermoons look brighter than ordinary full moons? Yes! By a noticeable amount. That’s because a supermoon exceeds the disk size of an average-sized moon by up to 8% and the brightness of an average-sized full moon by some 16%. And then, it exceeds the disk size of a micro-moon (a year’s most distant and therefore smallest full moon) up to 14% and the brightness of a micro-moon by some 30%. So, go outside on the night of a full supermoon. Even if you’re a casual observer of the moon, there’s a chance you’ll notice the supermoon is exceptionally bright!
A note to those in the Southern Hemisphere
If you’re in the Southern Hemisphere, your Harvest and Hunter’s Moons center on the March equinox, your autumnal equinox. Much of what we say in his post – the general information about Harvest and Hunter’s Moons – applies to you, too… next March and April.
Right now, your full moon will be doing the opposite of a Hunter’s Moon. That is, for the Southern Hemisphere around the time of the September and October full moons, there’s a longer-than-usual time between moonrises on successive nights.
For those of us in the Northern Hemisphere, it’s autumn now. That means the ecliptic – or sun and moon’s path – makes its narrowest angle with the horizon in early evening. Image via ClassicalAstronomy.com. Used with permission.
Tips and tricks to view the Super Hunter’s Moon
How did the Hunter’s Moon get its name?
There are many stories surrounding the names of the moons, including the Hunter’s Moon. From a practical standpoint, the Harvest Moon and subsequent Hunter’s Moon provided extra light in the evenings for farmers and hunters to finish their tasks.
Every full moon has a slew of nicknames tied to months of the year. But some moon names, such as the Harvest and Hunter’s Moons, are tied to seasons.
In North America, the Harvest Moon was a time when the bright moon meant farmers could stay out later, working in their fields, gathering in the crops before the first freeze. After the harvest, farmers would turn to hunting deer and other animals to bolster their food stores before winter. The bright light of the full moon and almost full moons would let them hunt into the evening hours. So, we call it a Hunter’s Moon.
Who named the Harvest and Hunter’s Moon? Those names probably sprang to the lips of farmers and hunters throughout the Northern Hemisphere, on autumn evenings, at times of the full moon.
Is a Hunter’s Moon bigger or brighter?
Generally, no. The Hunter’s Moon is just an ordinary full moon with a special path across our sky. Still, many of us do think the Hunter’s Moon looks bigger … or brighter … and more orange than usual. Why?
It’s because the Hunter’s Moon has a powerful mystique. Many people look for it shortly after sunset around the time of full moon. After sunset around any full moon, the moon will always be near the horizon … because full moons rise at sunset. It’s the location of the moon near the horizon that causes the Hunter’s Moon – or any full moon – to look big and orange in color.
The orange color of a moon near the horizon is a true physical effect. It stems from the fact that, when you look toward the horizon, you’re looking through a greater thickness of Earth’s atmosphere than when you gaze up and overhead. The atmosphere scatters blue light – that’s why the sky looks blue. The greater thickness of atmosphere in the direction of a horizon scatters blue light most effectively, but it lets red light pass through to your eyes. So a full moon near the horizon – any full moon near the horizon – takes on a yellow or orange or reddish hue.
The bigger-than-usual size of a moon seen near the horizon is something else entirely. It’s a trick that your eyes are playing – an illusion – called the Moon Illusion.
However, in 2024, the Hunter’s Moon is a supermoon. And it’s the closest supermoon in 2024. So yes, it will look brighter than an average full moon!
2024 full moon is in Pisces
The October full moon usually lies in front of one of three constellations of the zodiac: Pisces the Fish, Aries the Ram, or Cetus the Whale.
Typically, it’s in Pisces and that is the case for 2024.
The October 2024 full moon occurs on October 17 and lies in the constellation Pisces the Fish. It’s also the 3rd of 4 full supermoons in a row in 2024. Chart via EarthSky.
Hunter’s Moon photos from our community
View at EarthSky Community Photos. | Riste Spiroski in Ohrid, Macedonia, caught a full Hunter’s Moon in 2023, setting in the west in the morning. Thank you, Riste!View at EarthSky Community Photos. | Adelina Bathorja in Tirane, Albania, captured these images of the full moon on October 28, 2023. Adelina wrote: “Another beautiful full moon, the Hunter’s Moon.” Thank you, Adelina!View at EarthSky Community Photos. | Riste Spiroski in Ohrid, Macedonia, also captured this image of the October 28-29, 2023, moon. Riste wrote: “Full Hunter’s Moon was taken at its maximum partial eclipse at 10:14 p.m.” Thank you, Riste!View at EarthSky Community Photos. | Iaroslav Kourzenkov captured this image on October 28, 2023. Iaroslav wrote: “Hunter’s Moon and the penumbral lunar eclipse with Maugher Beach Lighthouse as seen from York Redoubt National Historic Site, Nova Scotia, Canada.” Thank you, Iaroslav!
Bottom line: The Super Hunter’s Moon – this year’s October full moon – is on October 17, 2024. Plus, it’s the closest – and brightest – supermoon of 2024.
The October 17 full moon is the Super Hunter’s Moon. It’s the 3rd of 4 supermoons in a row in 2024. It’ll rise in the east opposite the sunset, be highest in the sky around midnight and set in the west around sunrise. Chart via EarthSky.
It’s a full moon, the Hunter’s Moon and the closest supermoon of 2024.
Super Hunter’s Moon follows the Super Harvest Moon
When and where to look in 2024: For all of us on Earth, the bright, round full moon will rise in the east around sunset on October 17, 2024. It’ll be visible all night. Be sure to watch on the nights before and after that, too. This is the Northern Hemisphere’s Hunter’s Moon, the full moon after the Harvest Moon (which is the full moon closest to the autumnal equinox). This Hunter’s Moon is also the third of four supermoons in a row in 2024. The crest of the full moon falls that morning for the Americas at 11:26 UTC on October 17. That’s 6:26 a.m. CDT, about two hours before moonset in central North America. If you want to see the fullest possible moon, look in the west on the morning of October 17 before sunrise. The moon’s perigee, or closest point to Earth for this month, falls about 10 hours before the crest of the moon’s full phase. Perigee comes at 8 p.m. CDT on October 16 (1 UTC on October 17). So this is a very close full moon, known as a supermoon. In fact, it’s the closest supermoon of 2024! So it’ll be the brightest moon of this year. Characteristics of the Hunter’s Moon: The moon is always roundest on the day that it’s full. And, on the day of a full moon, the moon always rises close to the time of sunset. But the nights before and after a full moon feature a round-looking moon, too. And, like the Harvest Moon, this October Hunter’s moon will be characterized by a shorter-than-usual time between successive moonrises for several nights in a row. So Northern Hemisphere dwellers will see full-looking moons in twilight skies, ascending in the east as the sun sets in the west, for several nights around October 17. For the Southern Hemisphere, the nights around this full moon feature a longer-than-usual time between successive moonrises. So, for the southern part of the globe, the moon will rise on October 18, 19 and 20 (and for many nights after that) in a sky that’s already dark.
At full moon, the sun, Earth and moon are aligned in space, with Earth in the middle. The moon’s day side – its fully lighted hemisphere – directly faces us. Chart via EarthSky.
What’s special about a Hunter’s Moon?
A full moon is always opposite the sun in space, and opposite the sun in our sky. So all full moons rise in the east around sunset. And all full moons set in the west around sunrise. But the various full moons have different characteristics.
On average, the moon rises about 50 minutes later each day. But when a full moon happens close to the autumnal equinox – either a Harvest or a Hunter’s Moon – the moon (at mid-temperate latitudes) rises only about 30 to 35 minutes later daily for several days before and after the full moon. The reason is that the ecliptic – which more or less marks the path the moon travels across the sky – makes a narrow angle with the evening horizon around the time of the autumnal equinox.
The result is that there’s a shorter-than-usual lag time between successive moonrises around the full Hunter’s Moon.
Early evening moonrises make every Hunter’s Moon special. Every full moon rises around sunset. After the full Hunter’s Moon, you’ll see the moon ascending in the east relatively soon after sunset for a few days in a row at northerly latitudes.
A great source of moonrise times is the Custom Sunrise Sunset Calendar. Once you get to that page, be sure to click the box for “moon phases” and “moonrise and moonset times.”
By the way, since the Harvest Moon is the closest full moon to the equinox, it can come either before or after it. So the Harvest Moon can sometimes fall in October, which it does every three or four years. When the Harvest Moon falls in October, the Hunter’s Moon – the full moon following the Harvest Moon – will fall in early November.
That’ll happen next in 2025.
When the angle of the ecliptic is narrow, the moon rises noticeably farther north on your horizon from one night to the next. So there’s no long period of darkness between sunset and moonrise. In other words, around the time of an autumn full moon, many people see the rising moon ascending in the eastern sky in twilight for several evenings in a row. If you’re in the Southern Hemisphere, your evening ecliptic is nearly perpendicular to your early evening horizon now. You’ll see the full moon rise in twilight, but the next night’s moon comes up in darkness, much later at night. Image via ClassicalAstronomy.com. Used with permission.
A word about supermoons
A full supermoon happens when the full moon happens at – or near – the time the moon is closest to us in its elliptical orbit.
Of course, full supermoons draw a lot of attention and are very popular.
Do supermoons look bigger to the eye? Generally not, unless you’re an avid moon observer. But … do supermoons look brighter than ordinary full moons? Yes! By a noticeable amount. That’s because a supermoon exceeds the disk size of an average-sized moon by up to 8% and the brightness of an average-sized full moon by some 16%. And then, it exceeds the disk size of a micro-moon (a year’s most distant and therefore smallest full moon) up to 14% and the brightness of a micro-moon by some 30%. So, go outside on the night of a full supermoon. Even if you’re a casual observer of the moon, there’s a chance you’ll notice the supermoon is exceptionally bright!
A note to those in the Southern Hemisphere
If you’re in the Southern Hemisphere, your Harvest and Hunter’s Moons center on the March equinox, your autumnal equinox. Much of what we say in his post – the general information about Harvest and Hunter’s Moons – applies to you, too… next March and April.
Right now, your full moon will be doing the opposite of a Hunter’s Moon. That is, for the Southern Hemisphere around the time of the September and October full moons, there’s a longer-than-usual time between moonrises on successive nights.
For those of us in the Northern Hemisphere, it’s autumn now. That means the ecliptic – or sun and moon’s path – makes its narrowest angle with the horizon in early evening. Image via ClassicalAstronomy.com. Used with permission.
Tips and tricks to view the Super Hunter’s Moon
How did the Hunter’s Moon get its name?
There are many stories surrounding the names of the moons, including the Hunter’s Moon. From a practical standpoint, the Harvest Moon and subsequent Hunter’s Moon provided extra light in the evenings for farmers and hunters to finish their tasks.
Every full moon has a slew of nicknames tied to months of the year. But some moon names, such as the Harvest and Hunter’s Moons, are tied to seasons.
In North America, the Harvest Moon was a time when the bright moon meant farmers could stay out later, working in their fields, gathering in the crops before the first freeze. After the harvest, farmers would turn to hunting deer and other animals to bolster their food stores before winter. The bright light of the full moon and almost full moons would let them hunt into the evening hours. So, we call it a Hunter’s Moon.
Who named the Harvest and Hunter’s Moon? Those names probably sprang to the lips of farmers and hunters throughout the Northern Hemisphere, on autumn evenings, at times of the full moon.
Is a Hunter’s Moon bigger or brighter?
Generally, no. The Hunter’s Moon is just an ordinary full moon with a special path across our sky. Still, many of us do think the Hunter’s Moon looks bigger … or brighter … and more orange than usual. Why?
It’s because the Hunter’s Moon has a powerful mystique. Many people look for it shortly after sunset around the time of full moon. After sunset around any full moon, the moon will always be near the horizon … because full moons rise at sunset. It’s the location of the moon near the horizon that causes the Hunter’s Moon – or any full moon – to look big and orange in color.
The orange color of a moon near the horizon is a true physical effect. It stems from the fact that, when you look toward the horizon, you’re looking through a greater thickness of Earth’s atmosphere than when you gaze up and overhead. The atmosphere scatters blue light – that’s why the sky looks blue. The greater thickness of atmosphere in the direction of a horizon scatters blue light most effectively, but it lets red light pass through to your eyes. So a full moon near the horizon – any full moon near the horizon – takes on a yellow or orange or reddish hue.
The bigger-than-usual size of a moon seen near the horizon is something else entirely. It’s a trick that your eyes are playing – an illusion – called the Moon Illusion.
However, in 2024, the Hunter’s Moon is a supermoon. And it’s the closest supermoon in 2024. So yes, it will look brighter than an average full moon!
2024 full moon is in Pisces
The October full moon usually lies in front of one of three constellations of the zodiac: Pisces the Fish, Aries the Ram, or Cetus the Whale.
Typically, it’s in Pisces and that is the case for 2024.
The October 2024 full moon occurs on October 17 and lies in the constellation Pisces the Fish. It’s also the 3rd of 4 full supermoons in a row in 2024. Chart via EarthSky.
Hunter’s Moon photos from our community
View at EarthSky Community Photos. | Riste Spiroski in Ohrid, Macedonia, caught a full Hunter’s Moon in 2023, setting in the west in the morning. Thank you, Riste!View at EarthSky Community Photos. | Adelina Bathorja in Tirane, Albania, captured these images of the full moon on October 28, 2023. Adelina wrote: “Another beautiful full moon, the Hunter’s Moon.” Thank you, Adelina!View at EarthSky Community Photos. | Riste Spiroski in Ohrid, Macedonia, also captured this image of the October 28-29, 2023, moon. Riste wrote: “Full Hunter’s Moon was taken at its maximum partial eclipse at 10:14 p.m.” Thank you, Riste!View at EarthSky Community Photos. | Iaroslav Kourzenkov captured this image on October 28, 2023. Iaroslav wrote: “Hunter’s Moon and the penumbral lunar eclipse with Maugher Beach Lighthouse as seen from York Redoubt National Historic Site, Nova Scotia, Canada.” Thank you, Iaroslav!
Bottom line: The Super Hunter’s Moon – this year’s October full moon – is on October 17, 2024. Plus, it’s the closest – and brightest – supermoon of 2024.
Astronomers have observed Jupiter’s legendary Great Red Spot, an anticyclone large enough to swallow Earth, for at least 150 years. But Hubble’s new observations of the famous red storm reveal the Great Red Spot is not as stable as it might look. Recent data collected for 90 days from December 2023 to March 2024 show the Great Red Spot jiggles like a bowl of gelatin. The combined Hubble images allowed astronomers to assemble a time-lapse movie of the squiggly behavior of the Great Red Spot.
Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of the science paper published in the peer-reviewedThe Planetary Science Journal. Simon said:
While we knew its motion varies slightly in its longitude, we didn’t expect to see the size oscillate as well. As far as we know, it’s not been identified before. This is really the first time we’ve had the proper imaging cadence of the Great Red Spot. With Hubble’s high resolution we can say that the Great Red Spot is definitively squeezing in and out at the same time as it moves faster and slower. That was very unexpected, and at present there are no hydrodynamic explanations.
Watch Jupiter's Great Red Spot as it oscillates over time. Images from the Hubble Space Telescope between Dec 2023 and Mar 2024. pic.twitter.com/RZEzy1t8zf
Hubble monitors Jupiter and the other outer solar system planets every year through the Outer Planet Atmospheres Legacy program (OPAL) led by Simon. But these observations were from a program dedicated to the Great Red Spot. Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes on Earth into a broader cosmic context. This knowledge might be applied to better understanding the meteorology on planets around other stars.
Simon’s team used Hubble to zoom in on the Great Red Spot for a detailed look at its size, shape, and any subtle color changes. Simon said:
When we look closely, we see a lot of things are changing from day to day.
This includes ultraviolet-light observations showing that the distinct core of the storm gets brightest when the Great Red Spot is at its largest size in its oscillation cycle. This indicates less haze absorption in the upper atmosphere.
These 8 images are from the Hubble Space Telescope, taken across 90 days from December 2023 to March 2024. At the time, Jupiter ranged from 391 million miles (630 million km) to 512 million miles (823 million km) from the sun. Astronomers measured the Great Red Spot’s size, shape, brightness, color and vorticity over one full oscillation cycle. The data reveal that the Great Red Spot is not as stable as it might look. It went through an oscillation in its elliptical shape, jiggling like a bowl of gelatin. The cause of the 90-day oscillation is unknown. Image via NASA/ ESA/ Amy Simon (NASA-GSFC)/ processing: Joseph DePasquale (STScI).
The Great Red Spot is trapped between jet streams
Co-investigator Mike Wong of the University of California at Berkeley said:
As it accelerates and decelerates, the Great Red Spot is pushing against the windy jet streams to the north and south of it. It’s similar to a sandwich where the slices of bread are forced to bulge out when there’s too much filling in the middle.
Wong contrasted this to Neptune, where dark spots can drift wildly in latitude without strong jet streams to hold them in place. Jupiter’s Great Red Spot has been held at a southern latitude, trapped between the jet streams, for the extent of Earth-bound telescopic observations.
Astronomers used these 8 images of Jupiter from December 2023 to March 2024 to closely examine the movements of the Great Red Spot. Image via NASA/ ESA/ Amy Simon (NASA-GSFC)/ processing: Joseph DePasquale (STScI).
A shrinking storm?
The team has continued watching the Great Red Spot shrink since the OPAL program began 10 years ago. They predict it will keep shrinking before taking on a stable, less-elongated, shape. Simon said:
Right now it’s over-filling its latitude band relative to the wind field. Once it shrinks inside that band the winds will really be holding it in place.
The team predicts the Great Red Spot will probably stabilize in size, but for now Hubble only observed it for one oscillation cycle.
The researchers hope that in the future other high-resolution images from Hubble might identify other Jovian parameters that indicate the underlying cause of the oscillation.
The scientists presented their results at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho.
Bottom line: New observations with the Hubble Space Telescope show that Jupiter’s Great Red Spot wiggles like a bowl of gelatin. It squeezes in and out like a stress ball.
Astronomers have observed Jupiter’s legendary Great Red Spot, an anticyclone large enough to swallow Earth, for at least 150 years. But Hubble’s new observations of the famous red storm reveal the Great Red Spot is not as stable as it might look. Recent data collected for 90 days from December 2023 to March 2024 show the Great Red Spot jiggles like a bowl of gelatin. The combined Hubble images allowed astronomers to assemble a time-lapse movie of the squiggly behavior of the Great Red Spot.
Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of the science paper published in the peer-reviewedThe Planetary Science Journal. Simon said:
While we knew its motion varies slightly in its longitude, we didn’t expect to see the size oscillate as well. As far as we know, it’s not been identified before. This is really the first time we’ve had the proper imaging cadence of the Great Red Spot. With Hubble’s high resolution we can say that the Great Red Spot is definitively squeezing in and out at the same time as it moves faster and slower. That was very unexpected, and at present there are no hydrodynamic explanations.
Watch Jupiter's Great Red Spot as it oscillates over time. Images from the Hubble Space Telescope between Dec 2023 and Mar 2024. pic.twitter.com/RZEzy1t8zf
Hubble monitors Jupiter and the other outer solar system planets every year through the Outer Planet Atmospheres Legacy program (OPAL) led by Simon. But these observations were from a program dedicated to the Great Red Spot. Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes on Earth into a broader cosmic context. This knowledge might be applied to better understanding the meteorology on planets around other stars.
Simon’s team used Hubble to zoom in on the Great Red Spot for a detailed look at its size, shape, and any subtle color changes. Simon said:
When we look closely, we see a lot of things are changing from day to day.
This includes ultraviolet-light observations showing that the distinct core of the storm gets brightest when the Great Red Spot is at its largest size in its oscillation cycle. This indicates less haze absorption in the upper atmosphere.
These 8 images are from the Hubble Space Telescope, taken across 90 days from December 2023 to March 2024. At the time, Jupiter ranged from 391 million miles (630 million km) to 512 million miles (823 million km) from the sun. Astronomers measured the Great Red Spot’s size, shape, brightness, color and vorticity over one full oscillation cycle. The data reveal that the Great Red Spot is not as stable as it might look. It went through an oscillation in its elliptical shape, jiggling like a bowl of gelatin. The cause of the 90-day oscillation is unknown. Image via NASA/ ESA/ Amy Simon (NASA-GSFC)/ processing: Joseph DePasquale (STScI).
The Great Red Spot is trapped between jet streams
Co-investigator Mike Wong of the University of California at Berkeley said:
As it accelerates and decelerates, the Great Red Spot is pushing against the windy jet streams to the north and south of it. It’s similar to a sandwich where the slices of bread are forced to bulge out when there’s too much filling in the middle.
Wong contrasted this to Neptune, where dark spots can drift wildly in latitude without strong jet streams to hold them in place. Jupiter’s Great Red Spot has been held at a southern latitude, trapped between the jet streams, for the extent of Earth-bound telescopic observations.
Astronomers used these 8 images of Jupiter from December 2023 to March 2024 to closely examine the movements of the Great Red Spot. Image via NASA/ ESA/ Amy Simon (NASA-GSFC)/ processing: Joseph DePasquale (STScI).
A shrinking storm?
The team has continued watching the Great Red Spot shrink since the OPAL program began 10 years ago. They predict it will keep shrinking before taking on a stable, less-elongated, shape. Simon said:
Right now it’s over-filling its latitude band relative to the wind field. Once it shrinks inside that band the winds will really be holding it in place.
The team predicts the Great Red Spot will probably stabilize in size, but for now Hubble only observed it for one oscillation cycle.
The researchers hope that in the future other high-resolution images from Hubble might identify other Jovian parameters that indicate the underlying cause of the oscillation.
The scientists presented their results at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho.
Bottom line: New observations with the Hubble Space Telescope show that Jupiter’s Great Red Spot wiggles like a bowl of gelatin. It squeezes in and out like a stress ball.
It’s autumn for those of us in the Northern Hemisphere. There’s a chill in the air, and nights are getting long. Maybe you’ve been standing outside on an autumn evening, looking for the Big Dipper? It’s perhaps the most famous of all star patterns. You know you’re supposed to look northward. And you’re looking, but you can’t find it. Why not?
If you’re at a latitude of about 41 degrees north – or farther north – you will see the Dipper. From very northerly latitudes, the Big Dipper is circumpolar, or always above the northern horizon. If you’re below that latitude, though, you won’t find the Big Dipper in the evening now. In autumn, the Big Dipper is below your horizon during the evening hours.
Want to see it? If you’re in the southern U.S. or a comparable latitude, you’ll have to wait until the hours before dawn. At this time of the year, before dawn, you’ll easily see the Big Dipper ascending in the northeast.
To remember the best times to view the Big Dipper in the evening, remember the phrase: spring up and fall down. That’s because the Big Dipper shines way up high in the sky on spring evenings but close to the horizon on autumn evenings.
This animation shows the Big Dipper in autumn – and all 4 seasons – from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky.
5 Dipper stars are related
So you might or might not be able to see the Big Dipper now. But you can think about it. Did you know that the distances of the stars in the Dipper reveal something interesting about them? Five of these seven stars have a physical relationship in space. That’s not always true of patterns on our sky’s dome. Most star patterns are made up of unrelated stars at vastly different distances.
Where is the Big Dipper in autumn? It’s tough to spot on October evenings because it rides so low in the north. As always, the 2 outer stars in the Dipper’s bowl point to Polaris, the North Star.
Five of the Dipper’s stars – Merak, Mizar, Alioth, Megrez and Phecda – are part of a single star grouping. They probably were born together from a single cloud of gas and dust, and they’re still moving together as a family.
The other two stars in the Dipper – Dubhe and Alkaid – are unrelated to each other and to the other five. Here are the star distances to the Dipper’s stars:
View at EarthSky Community Photos. | Susan Jensen captured this image on September 6, 2024, and wrote: “Right place, right time! Standing on a gravel road in the middle of nowhere, looking across a stubble field. This slow-moving, vibrant meteor stopped me in my tracks! I was shooting the Big Dipper with the shutter locked to catch multiple frames for stacking when this monster did a slow flyby. How lucky that I was able to capture it!” Thank you, Susan!View at EarthSky Community Photos. | Jeremy Likness from Agate Beach, Newport, Oregon, captured this image on August 11, 2024, and wrote: “A Perseid meteor streaks across the curtain of aurora borealis rippling beneath the Big Dipper.” Thank you!
Bottom line: If you’re above 41 degrees north latitude, the Big Dipper star pattern is circumpolar; it stays in your sky always, circling around the northern pole star, Polaris. Below that latitude, the Dipper is below your horizon in the evening in autumn.
It’s autumn for those of us in the Northern Hemisphere. There’s a chill in the air, and nights are getting long. Maybe you’ve been standing outside on an autumn evening, looking for the Big Dipper? It’s perhaps the most famous of all star patterns. You know you’re supposed to look northward. And you’re looking, but you can’t find it. Why not?
If you’re at a latitude of about 41 degrees north – or farther north – you will see the Dipper. From very northerly latitudes, the Big Dipper is circumpolar, or always above the northern horizon. If you’re below that latitude, though, you won’t find the Big Dipper in the evening now. In autumn, the Big Dipper is below your horizon during the evening hours.
Want to see it? If you’re in the southern U.S. or a comparable latitude, you’ll have to wait until the hours before dawn. At this time of the year, before dawn, you’ll easily see the Big Dipper ascending in the northeast.
To remember the best times to view the Big Dipper in the evening, remember the phrase: spring up and fall down. That’s because the Big Dipper shines way up high in the sky on spring evenings but close to the horizon on autumn evenings.
This animation shows the Big Dipper in autumn – and all 4 seasons – from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky.
5 Dipper stars are related
So you might or might not be able to see the Big Dipper now. But you can think about it. Did you know that the distances of the stars in the Dipper reveal something interesting about them? Five of these seven stars have a physical relationship in space. That’s not always true of patterns on our sky’s dome. Most star patterns are made up of unrelated stars at vastly different distances.
Where is the Big Dipper in autumn? It’s tough to spot on October evenings because it rides so low in the north. As always, the 2 outer stars in the Dipper’s bowl point to Polaris, the North Star.
Five of the Dipper’s stars – Merak, Mizar, Alioth, Megrez and Phecda – are part of a single star grouping. They probably were born together from a single cloud of gas and dust, and they’re still moving together as a family.
The other two stars in the Dipper – Dubhe and Alkaid – are unrelated to each other and to the other five. Here are the star distances to the Dipper’s stars:
View at EarthSky Community Photos. | Susan Jensen captured this image on September 6, 2024, and wrote: “Right place, right time! Standing on a gravel road in the middle of nowhere, looking across a stubble field. This slow-moving, vibrant meteor stopped me in my tracks! I was shooting the Big Dipper with the shutter locked to catch multiple frames for stacking when this monster did a slow flyby. How lucky that I was able to capture it!” Thank you, Susan!View at EarthSky Community Photos. | Jeremy Likness from Agate Beach, Newport, Oregon, captured this image on August 11, 2024, and wrote: “A Perseid meteor streaks across the curtain of aurora borealis rippling beneath the Big Dipper.” Thank you!
Bottom line: If you’re above 41 degrees north latitude, the Big Dipper star pattern is circumpolar; it stays in your sky always, circling around the northern pole star, Polaris. Below that latitude, the Dipper is below your horizon in the evening in autumn.
