La Niña in late 2024? Spanish for “the girl,” La Niña is a periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. Typically, La Niña events occur every 3 to 5 years, but they can also happen over successive years, affecting weather around the globe. Image via NOAA’s World Ocean Database.
Will we have La Niña in late 2024?
NOAA’s Climate Prediction Center has issued a La Niña Watch, meaning that conditions are favorable for La Niña in late 2024 or early 2025. La Niña occurs when cold water from the depths of the equatorial Pacific rises up to the ocean surface, causing a change in weather patterns around the world.
NOAA is predicting a 60% chance for a weak La Niña event, developing in the Northern Hemisphere autumn months. And, if it happens, the La Niña is expected to persist through January-March, 2025. This event could lead to a dry and mild winter in the U.S. South and parts of Mexico, and a colder winter in the U.S. Northeast. And the northern tier of the U.S. and southern Canada could be wetter than average.
La Niña and El Niño are phases within the El Niño-Southern Oscillation, a naturally occurring global climate pattern. This pattern involves changes in wind and ocean temperatures in the Pacific and can cause extreme weather across the planet. La Nina is the cool phase of the pattern. And El Niño is the warm phase, occurring along with a weakening of trade winds that typically blow across the Pacific toward Asia. These winds weaken, allowing warm ocean waters to pile up along the western edge of South America.
These cold ocean temperatures and changes in the atmosphere affect the position of the jet stream — a narrow band of fast moving air flowing from west to east around the planet—by bumping it northward. The jet stream sits over the ocean and can tap into its moisture, influence the path storms take and boost precipitation.
Just recently Earth experienced a ‘triple-dip’ La Niña event from 2020 to 2023. ‘We had three back-to-back winters where we had La Niña conditions, which was unusual because the only other case of that happening was back in 1973 to 1976,’ said Michelle L’Heurex, a climate scientist at NOAA.
L’Heurex said that La Niña’s tend to last longer and be more recurrent than El Niño events.
La Niña in late 2024? Ocean surface waters have been cooler than usual in recent months. Image via NOAA.
Bottom line: The National Oceanic and Atmospheric Administration (NOAA) has issued a La Niña for the northern autumn of 2024. If it happens, conditions will likely persist to early 2025.
La Niña in late 2024? Spanish for “the girl,” La Niña is a periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. Typically, La Niña events occur every 3 to 5 years, but they can also happen over successive years, affecting weather around the globe. Image via NOAA’s World Ocean Database.
Will we have La Niña in late 2024?
NOAA’s Climate Prediction Center has issued a La Niña Watch, meaning that conditions are favorable for La Niña in late 2024 or early 2025. La Niña occurs when cold water from the depths of the equatorial Pacific rises up to the ocean surface, causing a change in weather patterns around the world.
NOAA is predicting a 60% chance for a weak La Niña event, developing in the Northern Hemisphere autumn months. And, if it happens, the La Niña is expected to persist through January-March, 2025. This event could lead to a dry and mild winter in the U.S. South and parts of Mexico, and a colder winter in the U.S. Northeast. And the northern tier of the U.S. and southern Canada could be wetter than average.
La Niña and El Niño are phases within the El Niño-Southern Oscillation, a naturally occurring global climate pattern. This pattern involves changes in wind and ocean temperatures in the Pacific and can cause extreme weather across the planet. La Nina is the cool phase of the pattern. And El Niño is the warm phase, occurring along with a weakening of trade winds that typically blow across the Pacific toward Asia. These winds weaken, allowing warm ocean waters to pile up along the western edge of South America.
These cold ocean temperatures and changes in the atmosphere affect the position of the jet stream — a narrow band of fast moving air flowing from west to east around the planet—by bumping it northward. The jet stream sits over the ocean and can tap into its moisture, influence the path storms take and boost precipitation.
Just recently Earth experienced a ‘triple-dip’ La Niña event from 2020 to 2023. ‘We had three back-to-back winters where we had La Niña conditions, which was unusual because the only other case of that happening was back in 1973 to 1976,’ said Michelle L’Heurex, a climate scientist at NOAA.
L’Heurex said that La Niña’s tend to last longer and be more recurrent than El Niño events.
La Niña in late 2024? Ocean surface waters have been cooler than usual in recent months. Image via NOAA.
Bottom line: The National Oceanic and Atmospheric Administration (NOAA) has issued a La Niña for the northern autumn of 2024. If it happens, conditions will likely persist to early 2025.
We’ve all seen a full moon looming large shortly after it rises, when it’s still hugging the horizon. And it’s true that the moon is sometimes closer to Earth than at other times, making it minutely larger in our sky. Yet the difference is barely discernible. When the moon viewed near the horizon looks larger than usual, your brain is playing a trick on you. It’s called the moon illusion.
You can check it out this week. On October 17, the Super Hunter’s Moon will be the closest supermoon in 2024. But even a brighter than normal supermoon will not look noticeably larger.
It’s all an illusion
We still don’t know the precise cause of the moon illusion. But the video above, from AsapSCIENCE, offers some explanations.
A common theory is when the moon is near the horizon, you’re seeing it in the company of many familiar visual reference points: trees, buildings, mountains and so on. Your brain automatically compares the moon to these reference points. But when the moon is higher up, there’s nothing to compare it to. As AsapSCIENCE says:
The moon seems smaller against the vastness of the night sky.
The moon looks bigger on the horizon. There is an optical illusion which makes the moon appear to be larger the lower it is in the sky. pic.twitter.com/zMAiAJ58g7
Maybe you’d like to test this theory yourself. According to NASA, here are some ways to prove it to yourself:
Hold up your outstretched index finger next to the moon. You’ll find that your fingernail and the moon are about the same size. Or try looking at the moon through a paper tube, or bend over and look backward between your legs. When you view it like this, the moon will be nowhere near as big as it had seemed.
Or NASA suggests:
Another ironclad way to size-check the moon is to take a photo when it’s near the horizon, and another when it’s high in the sky. If you keep your camera zoom settings the same, you’ll find that the moon is the same width, side to side, in both photos.
What about a red or orange moon?
By the way, there’s a second phenomenon that the moon displays when we see it near the horizon. That is, a low moon often appears red or orange in color. That reddish color is not an illusion. It’s a true physical effect, caused by the fact that – when the moon is low in the sky – you’re seeing it through a greater thickness of Earth’s atmosphere than when it’s overhead. The atmosphere filters out the bluer wavelengths of moonlight (which is really reflected sunlight). Meanwhile, it allows the red component of moonlight to travel straight through to your eyes. So a low moon is likely to look red or orange to you.
So how do people get those photos of extra big moons seen near a horizon? Photographers use zoom lenses and have familiar objects in the foreground making the more distant moon look huge. So they’re the result of photographic tricks and techniques, which you can read about here or here.
Some photos from our EarthSky Community
View at EarthSky Community Photos. | A great example of the moon illusion from Stephanie Becker in Soda Springs, California. She captured this image of the July full supermoon on July 2, 2023. Thank you, Stephanie!View at EarthSky Community Photos. | Cecille Kennedy in Depoe Bay, Oregon, captured this image on August 30, 2023. Cecille wrote: “The blue supermoon shines behind the clouds as it rises over the hills and the trees. A few minutes before the moon rose, the clouds were lavender rose pink. Then the lovely moon appeared.” Thank you, Cecille!
Bottom line: It’s the Super Hunter’s Moon this week. You might see an extra-large-looking moon low in the sky. It’s the moon illusion that makes the moon look so big.
Did you get a great photo of the Super Hunter’s Moon? Submit your photos here. We love to see them!
We’ve all seen a full moon looming large shortly after it rises, when it’s still hugging the horizon. And it’s true that the moon is sometimes closer to Earth than at other times, making it minutely larger in our sky. Yet the difference is barely discernible. When the moon viewed near the horizon looks larger than usual, your brain is playing a trick on you. It’s called the moon illusion.
You can check it out this week. On October 17, the Super Hunter’s Moon will be the closest supermoon in 2024. But even a brighter than normal supermoon will not look noticeably larger.
It’s all an illusion
We still don’t know the precise cause of the moon illusion. But the video above, from AsapSCIENCE, offers some explanations.
A common theory is when the moon is near the horizon, you’re seeing it in the company of many familiar visual reference points: trees, buildings, mountains and so on. Your brain automatically compares the moon to these reference points. But when the moon is higher up, there’s nothing to compare it to. As AsapSCIENCE says:
The moon seems smaller against the vastness of the night sky.
The moon looks bigger on the horizon. There is an optical illusion which makes the moon appear to be larger the lower it is in the sky. pic.twitter.com/zMAiAJ58g7
Maybe you’d like to test this theory yourself. According to NASA, here are some ways to prove it to yourself:
Hold up your outstretched index finger next to the moon. You’ll find that your fingernail and the moon are about the same size. Or try looking at the moon through a paper tube, or bend over and look backward between your legs. When you view it like this, the moon will be nowhere near as big as it had seemed.
Or NASA suggests:
Another ironclad way to size-check the moon is to take a photo when it’s near the horizon, and another when it’s high in the sky. If you keep your camera zoom settings the same, you’ll find that the moon is the same width, side to side, in both photos.
What about a red or orange moon?
By the way, there’s a second phenomenon that the moon displays when we see it near the horizon. That is, a low moon often appears red or orange in color. That reddish color is not an illusion. It’s a true physical effect, caused by the fact that – when the moon is low in the sky – you’re seeing it through a greater thickness of Earth’s atmosphere than when it’s overhead. The atmosphere filters out the bluer wavelengths of moonlight (which is really reflected sunlight). Meanwhile, it allows the red component of moonlight to travel straight through to your eyes. So a low moon is likely to look red or orange to you.
So how do people get those photos of extra big moons seen near a horizon? Photographers use zoom lenses and have familiar objects in the foreground making the more distant moon look huge. So they’re the result of photographic tricks and techniques, which you can read about here or here.
Some photos from our EarthSky Community
View at EarthSky Community Photos. | A great example of the moon illusion from Stephanie Becker in Soda Springs, California. She captured this image of the July full supermoon on July 2, 2023. Thank you, Stephanie!View at EarthSky Community Photos. | Cecille Kennedy in Depoe Bay, Oregon, captured this image on August 30, 2023. Cecille wrote: “The blue supermoon shines behind the clouds as it rises over the hills and the trees. A few minutes before the moon rose, the clouds were lavender rose pink. Then the lovely moon appeared.” Thank you, Cecille!
Bottom line: It’s the Super Hunter’s Moon this week. You might see an extra-large-looking moon low in the sky. It’s the moon illusion that makes the moon look so big.
Did you get a great photo of the Super Hunter’s Moon? Submit your photos here. We love to see them!
Here’s a comparison of the sun at solar minimum, from December 2019, and solar maximum, from May 2024. Image via NASA/ SDO.
NOAA and NASA announced solar maximum has arrived. Solar maximum is the peak of activity in the sun’s 11-year solar cycle.
Signs of the peak of the sun’s cycle include the magnetic poles flipping and a high number of sunspots on the sun’s surface.
We can still expect to see more aurora in the months to come. Scientists won’t know the exact month of the peak and its length until they look back on the data.
In a teleconference with reporters on Tuesday, October 15, 2024, representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel announced that the sun has reached its solar maximum period, which could continue for the next year.
The solar cycle is a natural cycle the sun goes through as it transitions between low and high magnetic activity. Roughly every 11 years, at the height of the solar cycle, the sun’s magnetic poles flip — on Earth, that’d be like the North and South poles swapping places every decade — and the sun transitions from being calm to an active and stormy state.
NASA and NOAA track sunspots to determine and predict the progress of the solar cycle … and ultimately, solar activity. Sunspots are cooler regions on the sun caused by a concentration of magnetic field lines. Sunspots are the visible component of active regions, areas of intense and complex magnetic fields on the sun that are the source of solar eruptions.
Jamie Favors, director of the Space Weather Program at NASA Headquarters in Washington, said:
During solar maximum, the number of sunspots, and therefore, the amount of solar activity, increases. This increase in activity provides an exciting opportunity to learn about our closest star. But it also causes real effects at Earth and throughout our solar system.
Solar activity leads to space weather
Solar activity strongly influences conditions in space known as space weather. This can affect satellites and astronauts in space, as well as communications and navigation systems — such as radio and GPS — and power grids on Earth. When the sun is most active, space weather events become more frequent. Solar activity has led to increased aurora visibility and impacts on satellites and infrastructure in recent months.
During May 2024, a barrage of large solar flares and coronal mass ejections (CMEs) launched clouds of charged particles and magnetic fields toward Earth, creating the strongest geomagnetic storm at Earth in two decades. And it was possibly among the strongest displays of auroras on record in the past 500 years.
Elsayed Talaat, director of space weather operations at NOAA, said:
This announcement doesn’t mean that this is the peak of solar activity we’ll see this solar cycle. While the sun has reached the solar maximum period, the month that solar activity peaks on the sun will not be identified for months or years.
When is the exact peak of solar maximum?
Scientists will not be able to determine the exact peak of this solar maximum period for many months because it’s only identifiable after they’ve tracked a consistent decline in solar activity after that peak.
However, scientists have identified that the last two years on the sun have been part of this active phase of the solar cycle. That’s due to the consistently high number of sunspots during this period. Scientists anticipate the maximum phase will last another year or so before the sun enters the declining phase. And that leads back to solar minimum. Since 1989, the Solar Cycle Prediction Panel — an international panel of experts sponsored by NASA and NOAA — has worked together to make their prediction for the next solar cycle.
Solar cycles have been tracked by astronomers since Galileo first observed sunspots in the 1600s. Each solar cycle is different. Some cycles peak for larger and shorter amounts of time, and others have smaller peaks that last longer.
This is the sunspot number over the previous 24 solar cycles. Scientists use sunspots to track solar cycle progress. The dark spots are associated with solar activity, often as the origins for giant explosions. For example, solar flares or coronal mass ejections are giant explosions that can spew light, energy and solar material out into space. Image via NOAA’s Space Weather Prediction Center.
Solar maximum is slightly exceeding expectations
Lisa Upton, co-chair of the Solar Cycle Prediction Panel and lead scientist at Southwest Research Institute in San Antonio, Texas, said:
Solar Cycle 25 sunspot activity has slightly exceeded expectations. However, despite seeing a few large storms, they aren’t larger than what we might expect during the maximum phase of the cycle.
The most powerful flare of the solar cycle so far was an X9.0 on October 3. (X-class denotes the most intense flares, while the number provides more information about its strength.)
NOAA anticipates additional solar and geomagnetic storms during the current solar maximum period. This will lead to opportunities to spot auroras over the next several months, as well as potential technology impacts. Additionally, though less frequent, scientists often see fairly significant storms during the declining phase of the solar cycle.
The Solar Cycle 25 forecast, produced by the Solar Cycle 25 Prediction Panel, which is co-chaired by NASA and NOAA. Sunspot number is an indicator of solar cycle strength. The higher the sunspot number, the stronger the cycle. Image via NOAA’s Space Weather Prediction Center.
Future of space weather prediction
NASA and NOAA are preparing for the future of space weather research and prediction. In December 2024, NASA’s Parker Solar Probe mission will make its closest-ever approach to the sun, beating its own record of closest human-made object to the sun. This will be the first of three planned approaches for Parker at this distance, helping researchers to understand space weather right at the source.
NASA is launching several missions over the next year that will help us better understand space weather and its impacts across the solar system.
Space weather predictions are critical for supporting the spacecraft and astronauts of NASA’s Artemis campaign. Surveying this space environment is a vital part of understanding and mitigating astronaut exposure to space radiation.
NASA works as a research arm of the nation’s space weather effort. To see how space weather can affect Earth, please visit NOAA’s Space Weather Prediction Center, the U.S. government’s official source for space weather forecasts, watches, warnings, and alerts.
Bottom line: NASA and NOAA announced on October 15, 2024, that the sun has reached the peak of its 11-year solar cycle, or what is known as solar maximum.
Here’s a comparison of the sun at solar minimum, from December 2019, and solar maximum, from May 2024. Image via NASA/ SDO.
NOAA and NASA announced solar maximum has arrived. Solar maximum is the peak of activity in the sun’s 11-year solar cycle.
Signs of the peak of the sun’s cycle include the magnetic poles flipping and a high number of sunspots on the sun’s surface.
We can still expect to see more aurora in the months to come. Scientists won’t know the exact month of the peak and its length until they look back on the data.
In a teleconference with reporters on Tuesday, October 15, 2024, representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel announced that the sun has reached its solar maximum period, which could continue for the next year.
The solar cycle is a natural cycle the sun goes through as it transitions between low and high magnetic activity. Roughly every 11 years, at the height of the solar cycle, the sun’s magnetic poles flip — on Earth, that’d be like the North and South poles swapping places every decade — and the sun transitions from being calm to an active and stormy state.
NASA and NOAA track sunspots to determine and predict the progress of the solar cycle … and ultimately, solar activity. Sunspots are cooler regions on the sun caused by a concentration of magnetic field lines. Sunspots are the visible component of active regions, areas of intense and complex magnetic fields on the sun that are the source of solar eruptions.
Jamie Favors, director of the Space Weather Program at NASA Headquarters in Washington, said:
During solar maximum, the number of sunspots, and therefore, the amount of solar activity, increases. This increase in activity provides an exciting opportunity to learn about our closest star. But it also causes real effects at Earth and throughout our solar system.
Solar activity leads to space weather
Solar activity strongly influences conditions in space known as space weather. This can affect satellites and astronauts in space, as well as communications and navigation systems — such as radio and GPS — and power grids on Earth. When the sun is most active, space weather events become more frequent. Solar activity has led to increased aurora visibility and impacts on satellites and infrastructure in recent months.
During May 2024, a barrage of large solar flares and coronal mass ejections (CMEs) launched clouds of charged particles and magnetic fields toward Earth, creating the strongest geomagnetic storm at Earth in two decades. And it was possibly among the strongest displays of auroras on record in the past 500 years.
Elsayed Talaat, director of space weather operations at NOAA, said:
This announcement doesn’t mean that this is the peak of solar activity we’ll see this solar cycle. While the sun has reached the solar maximum period, the month that solar activity peaks on the sun will not be identified for months or years.
When is the exact peak of solar maximum?
Scientists will not be able to determine the exact peak of this solar maximum period for many months because it’s only identifiable after they’ve tracked a consistent decline in solar activity after that peak.
However, scientists have identified that the last two years on the sun have been part of this active phase of the solar cycle. That’s due to the consistently high number of sunspots during this period. Scientists anticipate the maximum phase will last another year or so before the sun enters the declining phase. And that leads back to solar minimum. Since 1989, the Solar Cycle Prediction Panel — an international panel of experts sponsored by NASA and NOAA — has worked together to make their prediction for the next solar cycle.
Solar cycles have been tracked by astronomers since Galileo first observed sunspots in the 1600s. Each solar cycle is different. Some cycles peak for larger and shorter amounts of time, and others have smaller peaks that last longer.
This is the sunspot number over the previous 24 solar cycles. Scientists use sunspots to track solar cycle progress. The dark spots are associated with solar activity, often as the origins for giant explosions. For example, solar flares or coronal mass ejections are giant explosions that can spew light, energy and solar material out into space. Image via NOAA’s Space Weather Prediction Center.
Solar maximum is slightly exceeding expectations
Lisa Upton, co-chair of the Solar Cycle Prediction Panel and lead scientist at Southwest Research Institute in San Antonio, Texas, said:
Solar Cycle 25 sunspot activity has slightly exceeded expectations. However, despite seeing a few large storms, they aren’t larger than what we might expect during the maximum phase of the cycle.
The most powerful flare of the solar cycle so far was an X9.0 on October 3. (X-class denotes the most intense flares, while the number provides more information about its strength.)
NOAA anticipates additional solar and geomagnetic storms during the current solar maximum period. This will lead to opportunities to spot auroras over the next several months, as well as potential technology impacts. Additionally, though less frequent, scientists often see fairly significant storms during the declining phase of the solar cycle.
The Solar Cycle 25 forecast, produced by the Solar Cycle 25 Prediction Panel, which is co-chaired by NASA and NOAA. Sunspot number is an indicator of solar cycle strength. The higher the sunspot number, the stronger the cycle. Image via NOAA’s Space Weather Prediction Center.
Future of space weather prediction
NASA and NOAA are preparing for the future of space weather research and prediction. In December 2024, NASA’s Parker Solar Probe mission will make its closest-ever approach to the sun, beating its own record of closest human-made object to the sun. This will be the first of three planned approaches for Parker at this distance, helping researchers to understand space weather right at the source.
NASA is launching several missions over the next year that will help us better understand space weather and its impacts across the solar system.
Space weather predictions are critical for supporting the spacecraft and astronauts of NASA’s Artemis campaign. Surveying this space environment is a vital part of understanding and mitigating astronaut exposure to space radiation.
NASA works as a research arm of the nation’s space weather effort. To see how space weather can affect Earth, please visit NOAA’s Space Weather Prediction Center, the U.S. government’s official source for space weather forecasts, watches, warnings, and alerts.
Bottom line: NASA and NOAA announced on October 15, 2024, that the sun has reached the peak of its 11-year solar cycle, or what is known as solar maximum.
Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. Chart via EarthSky.
Piscis Austrinus has few bright stars and very faint deep-sky objects. The constellation of the Southern Fish is close to Capricornus in the spring sky for those in the Southern Hemisphere. Northern Hemisphere residents who don’t live too far north and want to catch a peek of this constellation can look below the constellations Capricornus and Aquarius in the fall. Piscis Austrinus has a vague, kite-shaped, fishlike form.
Piscis Austrinus was one of the 48 constellations that Ptolemy named in the 2nd century. The constellation was once larger, containing the stars that are now part of Grus the Crane.
Its only bright star
Piscis Austrinus has one very bright star: Fomalhaut. Fomalhaut, also known as Alpha Piscis Austrini, is magnitude 1.17 and lies 25 light-years away. Its name means the mouth of the fish in Arabic. Fomalhaut is the 18th brightest star in the sky. It is a white, A-type star.
In 2024, the bright planet Saturn can help you find Fomalhaut.
On October evenings in 2024, Saturn can guide you to the lonely, but bright, star Fomalhaut. They are the brightest object in that area of the sky. Chart via EarthSky.
Other stars of Piscis Austrinus
The next brightest stars in this constellation are magnitude 4.1 Epsilon, magnitude 4.2 Delta, magnitude 4.2 Beta and magnitude 4.3 Iota Piscis Austrini.
In the farthest southeastern corner of the constellation boundary is a star known by a few names, including Lacaille 9352 and GSC 7512:12363. Lacaille 9352 is unremarkable at magnitude 7.3, but it is one of the closest stars to the sun at 10.72 light-years away. This red dwarf is also notable in its proper motion. As one of the fastest-moving stars known, it travels at approximately 75 miles per second (120 kilometers per second).
Stars in Piscis Austrinus, the Southern Fish, include Fomalhaut. Image via International Astronomical Union/ Sky & Telescope/ Wikimedia Commons (CC BY 3.0).
A faint fuzzy in Piscis Austrinus
The deep-sky objects in Piscis Austrinus are all very faint. One of the “brightest” of these faint fuzzies is NGC 7314, a spiral galaxy at magnitude 10.9.
Bottom line: Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. From the Northern Hemisphere, look south in autumn to find it. From the Southern Hemisphere, look high overhead.
Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. Chart via EarthSky.
Piscis Austrinus has few bright stars and very faint deep-sky objects. The constellation of the Southern Fish is close to Capricornus in the spring sky for those in the Southern Hemisphere. Northern Hemisphere residents who don’t live too far north and want to catch a peek of this constellation can look below the constellations Capricornus and Aquarius in the fall. Piscis Austrinus has a vague, kite-shaped, fishlike form.
Piscis Austrinus was one of the 48 constellations that Ptolemy named in the 2nd century. The constellation was once larger, containing the stars that are now part of Grus the Crane.
Its only bright star
Piscis Austrinus has one very bright star: Fomalhaut. Fomalhaut, also known as Alpha Piscis Austrini, is magnitude 1.17 and lies 25 light-years away. Its name means the mouth of the fish in Arabic. Fomalhaut is the 18th brightest star in the sky. It is a white, A-type star.
In 2024, the bright planet Saturn can help you find Fomalhaut.
On October evenings in 2024, Saturn can guide you to the lonely, but bright, star Fomalhaut. They are the brightest object in that area of the sky. Chart via EarthSky.
Other stars of Piscis Austrinus
The next brightest stars in this constellation are magnitude 4.1 Epsilon, magnitude 4.2 Delta, magnitude 4.2 Beta and magnitude 4.3 Iota Piscis Austrini.
In the farthest southeastern corner of the constellation boundary is a star known by a few names, including Lacaille 9352 and GSC 7512:12363. Lacaille 9352 is unremarkable at magnitude 7.3, but it is one of the closest stars to the sun at 10.72 light-years away. This red dwarf is also notable in its proper motion. As one of the fastest-moving stars known, it travels at approximately 75 miles per second (120 kilometers per second).
Stars in Piscis Austrinus, the Southern Fish, include Fomalhaut. Image via International Astronomical Union/ Sky & Telescope/ Wikimedia Commons (CC BY 3.0).
A faint fuzzy in Piscis Austrinus
The deep-sky objects in Piscis Austrinus are all very faint. One of the “brightest” of these faint fuzzies is NGC 7314, a spiral galaxy at magnitude 10.9.
Bottom line: Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. From the Northern Hemisphere, look south in autumn to find it. From the Southern Hemisphere, look high overhead.
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.
