Can earthquakes be triggered by intense weather?

Aftermath of an earthquake on Japan’s Noto Peninsula that took place on January 1, 2024. A new study from MIT, focused on earthquakes in Japan, suggests that heavy snowfall and rainfall can contribute to triggering swarms of earthquakes. Image via Japan Ministry of Defense/ Wikimedia Commons (CC BY 4.0).

• Researchers looked for patterns in an earthquake swarm that started on the Noto Peninsula of Japan in late 2020.
• They found a correlation between the earthquakes and seasonal periods of heavy snow and rain.
• The snow and rain increase fluid pressure in cracks and fissures in subsurface bedrock, contributing to regular earthquake triggers and producing earthquake swarms.

Can intense weather trigger earthquakes?

Earthquakes happen when movement below Earth’s surface – such as shifting tectonic plates and faults – occurs. But could other factors also be at play? On May 8, 2024, researchers at the Massachusetts Institute of Technology (MIT) said climate and certain intense weather events may also help trigger earthquakes. In particular, heavy snowfall and rain can play a role. The new report focuses on a swarm of earthquakes in Japan over the past few years.

The researchers, led by former MIT research associate Qing-Yu Wang (now at Grenoble Alpes University), published their peer-reviewed findings in Science Advances on May 8, 2024.

Please help keep our site focused on quality content by donating to our cause. Your support allows us to keep delivering the informative articles you love.

Snowfall and rain contributed to earthquakes in Japan

The researchers focused on a series of earthquakes that have been occurring on the Noto Peninsula in Japan since 2020. The paper stated:

Since late 2020, a swarm of crustal earthquakes in the northeastern region of the Noto Peninsula, Japan, far from the plate boundaries of the subducting Pacific and Philippine plates, has been responsible for hundreds of earthquakes per day. Unlike typical subduction zone interplate earthquakes, inland crustal earthquakes in Japan islands predominantly take place at relatively shallow depths … Earthquake locations show that the Noto earthquake swarm started at a depth of about 15 km (9 mi), deeper than typical crustal earthquakes, and has since slowly migrated northeast toward the surface. This suggests that … there is an underlying forcing that is driving the earthquakes.

Connection between earthquakes and precipitation events

What is the underlying forcing? The new study suggests heavy snowfall and rain are at least part of the reason. The researchers found the start of the earthquake swarm matched up with strong precipitation events of heavy snow or rain. Study co-author William Frank at MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) said:

We see that snowfall and other environmental loading at the surface impacts the stress state underground, and the timing of intense precipitation events is well-correlated with the start of this earthquake swarm. So, climate obviously has an impact on the response of the solid earth, and part of that response is earthquakes.

The changes in underground pressure also correlate with seasonal patterns of snowfall and rainfall. Moreover, this pattern may occur elsewhere as well, not just in Japan.

Earthquake swarm and seismic velocity

The earthquakes in Japan – hundreds since late 2020 – are what scientists call an earthquake swarm. Instead of one big initial earthquake, followed by aftershocks, these are ongoing swarms of earthquakes without an initial bigger earthquake to trigger them. The research team at MIT, as well as scientists in Japan, looked for patterns in the swarms. Using the Japanese Meteorological Agency’s catalog of earthquakes, they examined earthquakes on Noto Peninsula over the past 11 years.

And indeed, they found something interesting. Before 2020, the recorded earthquakes were sporadic in nature. But after 2020, the earthquakes became more intense. They also began to cluster, which was the beginning of the swarm. To check this further, the researchers compared those results with another dataset from monitoring stations during the same 11-year period. The researchers wanted to check the speed, or the “seismic velocity,” of the seismic events, as in how fast a seismic wave traveled between monitoring stations.

The speed depends on the structure of the subsurface. The results supported the earlier findings. The seismic velocities changed when the earthquake swarm started and were also synchronized with the changing seasons. That was a big clue. Frank said:

We then had to explain why we were observing this seasonal variation.

Weight from snow and rain

So there was a demonstrated connection to the changing seasons. But why, exactly? Could changes in the environment somehow affect the subsurface where the earthquakes occurred? The answer had to do with seasonal precipitation. Snow or rain could affect the pore fluid pressure beneath the surface. This is the pressure from fluids in cracks and fissures in bedrock. As Frank explained:

When it rains or snows, that adds weight, which increases pore pressure, which allows seismic waves to travel through slower. When all that weight is removed, through evaporation or runoff, all of a sudden, that pore pressure decreases and seismic waves are faster.

So how could Wang and the team test this further? They created a hydromechanical model of the Noto Peninsula to simulate the underlying pore pressure over the last 11 years in response to seasonal changes in precipitation. The data included measurements of daily snow, rainfall and sea-level changes. The team used the data to track changes in excess pore pressure. Again, the results matched up with previous findings, as Frank noted:

We had seismic velocity observations, and we had the model of excess pore pressure, and when we overlapped them, we saw they just fit extremely well.

Noto Peninsula, Japan, as seen from the space shuttle in 2005. Image via Wikimedia Commons (public domain).

Snowfall the biggest contributor

Snowfall in particular had the strongest effect. So the periods of heavy snowfall helped to trigger the earthquake swarm. Frank added:

We can see that the timing of these earthquakes lines up extremely well with multiple times where we see intense snowfall. It’s well-correlated with earthquake activity. And we think there’s a physical link between the two.

The researchers note that while heavy snowfall and rain can contribute to producing an earthquake swarm, the original trigger is, as usual, in the subsurface. The climate and events simply enhance the effects. Frank said:

When we first want to understand how earthquakes work, we look to plate tectonics, because that is and will always be the number one reason why an earthquake happens. But, what are the other things that could affect when and how an earthquake happens? That’s when you start to go to second-order controlling factors, and the climate is obviously one of those.

Bottom line: A new study from MIT shows that climate and intense weather events like heavy snowfall and rain helped produce a swarm of earthquakes in Japan starting in 2020.

Source: Untangling the environmental and tectonic drivers of the Noto earthquake swarm in Japan

Via MIT

Read more: Are some modern earthquakes aftershocks from the 1800s?

Read more: Can we predict earthquakes now? No, but there’s news

The post Can earthquakes be triggered by intense weather? first appeared on EarthSky.

from EarthSky https://ift.tt/sVOAycd

Aftermath of an earthquake on Japan’s Noto Peninsula that took place on January 1, 2024. A new study from MIT, focused on earthquakes in Japan, suggests that heavy snowfall and rainfall can contribute to triggering swarms of earthquakes. Image via Japan Ministry of Defense/ Wikimedia Commons (CC BY 4.0).

• Researchers looked for patterns in an earthquake swarm that started on the Noto Peninsula of Japan in late 2020.
• They found a correlation between the earthquakes and seasonal periods of heavy snow and rain.
• The snow and rain increase fluid pressure in cracks and fissures in subsurface bedrock, contributing to regular earthquake triggers and producing earthquake swarms.

Can intense weather trigger earthquakes?

Earthquakes happen when movement below Earth’s surface – such as shifting tectonic plates and faults – occurs. But could other factors also be at play? On May 8, 2024, researchers at the Massachusetts Institute of Technology (MIT) said climate and certain intense weather events may also help trigger earthquakes. In particular, heavy snowfall and rain can play a role. The new report focuses on a swarm of earthquakes in Japan over the past few years.

The researchers, led by former MIT research associate Qing-Yu Wang (now at Grenoble Alpes University), published their peer-reviewed findings in Science Advances on May 8, 2024.

Please help keep our site focused on quality content by donating to our cause. Your support allows us to keep delivering the informative articles you love.

Snowfall and rain contributed to earthquakes in Japan

The researchers focused on a series of earthquakes that have been occurring on the Noto Peninsula in Japan since 2020. The paper stated:

Since late 2020, a swarm of crustal earthquakes in the northeastern region of the Noto Peninsula, Japan, far from the plate boundaries of the subducting Pacific and Philippine plates, has been responsible for hundreds of earthquakes per day. Unlike typical subduction zone interplate earthquakes, inland crustal earthquakes in Japan islands predominantly take place at relatively shallow depths … Earthquake locations show that the Noto earthquake swarm started at a depth of about 15 km (9 mi), deeper than typical crustal earthquakes, and has since slowly migrated northeast toward the surface. This suggests that … there is an underlying forcing that is driving the earthquakes.

Connection between earthquakes and precipitation events

What is the underlying forcing? The new study suggests heavy snowfall and rain are at least part of the reason. The researchers found the start of the earthquake swarm matched up with strong precipitation events of heavy snow or rain. Study co-author William Frank at MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) said:

We see that snowfall and other environmental loading at the surface impacts the stress state underground, and the timing of intense precipitation events is well-correlated with the start of this earthquake swarm. So, climate obviously has an impact on the response of the solid earth, and part of that response is earthquakes.

The changes in underground pressure also correlate with seasonal patterns of snowfall and rainfall. Moreover, this pattern may occur elsewhere as well, not just in Japan.

Earthquake swarm and seismic velocity

The earthquakes in Japan – hundreds since late 2020 – are what scientists call an earthquake swarm. Instead of one big initial earthquake, followed by aftershocks, these are ongoing swarms of earthquakes without an initial bigger earthquake to trigger them. The research team at MIT, as well as scientists in Japan, looked for patterns in the swarms. Using the Japanese Meteorological Agency’s catalog of earthquakes, they examined earthquakes on Noto Peninsula over the past 11 years.

And indeed, they found something interesting. Before 2020, the recorded earthquakes were sporadic in nature. But after 2020, the earthquakes became more intense. They also began to cluster, which was the beginning of the swarm. To check this further, the researchers compared those results with another dataset from monitoring stations during the same 11-year period. The researchers wanted to check the speed, or the “seismic velocity,” of the seismic events, as in how fast a seismic wave traveled between monitoring stations.

The speed depends on the structure of the subsurface. The results supported the earlier findings. The seismic velocities changed when the earthquake swarm started and were also synchronized with the changing seasons. That was a big clue. Frank said:

We then had to explain why we were observing this seasonal variation.

Weight from snow and rain

So there was a demonstrated connection to the changing seasons. But why, exactly? Could changes in the environment somehow affect the subsurface where the earthquakes occurred? The answer had to do with seasonal precipitation. Snow or rain could affect the pore fluid pressure beneath the surface. This is the pressure from fluids in cracks and fissures in bedrock. As Frank explained:

When it rains or snows, that adds weight, which increases pore pressure, which allows seismic waves to travel through slower. When all that weight is removed, through evaporation or runoff, all of a sudden, that pore pressure decreases and seismic waves are faster.

So how could Wang and the team test this further? They created a hydromechanical model of the Noto Peninsula to simulate the underlying pore pressure over the last 11 years in response to seasonal changes in precipitation. The data included measurements of daily snow, rainfall and sea-level changes. The team used the data to track changes in excess pore pressure. Again, the results matched up with previous findings, as Frank noted:

We had seismic velocity observations, and we had the model of excess pore pressure, and when we overlapped them, we saw they just fit extremely well.

Noto Peninsula, Japan, as seen from the space shuttle in 2005. Image via Wikimedia Commons (public domain).

Snowfall the biggest contributor

Snowfall in particular had the strongest effect. So the periods of heavy snowfall helped to trigger the earthquake swarm. Frank added:

We can see that the timing of these earthquakes lines up extremely well with multiple times where we see intense snowfall. It’s well-correlated with earthquake activity. And we think there’s a physical link between the two.

The researchers note that while heavy snowfall and rain can contribute to producing an earthquake swarm, the original trigger is, as usual, in the subsurface. The climate and events simply enhance the effects. Frank said:

When we first want to understand how earthquakes work, we look to plate tectonics, because that is and will always be the number one reason why an earthquake happens. But, what are the other things that could affect when and how an earthquake happens? That’s when you start to go to second-order controlling factors, and the climate is obviously one of those.

Bottom line: A new study from MIT shows that climate and intense weather events like heavy snowfall and rain helped produce a swarm of earthquakes in Japan starting in 2020.

Source: Untangling the environmental and tectonic drivers of the Noto earthquake swarm in Japan

Via MIT

Read more: Are some modern earthquakes aftershocks from the 1800s?

Read more: Can we predict earthquakes now? No, but there’s news

The post Can earthquakes be triggered by intense weather? first appeared on EarthSky.

from EarthSky https://ift.tt/sVOAycd

Mimosa, 2nd-brightest star in Crux, the Southern Cross

Crux, the Southern Cross, and its major stars. Mimosa is on the left near the Jewel Box Cluster. This is the view from a southerly latitude (around 25 degrees north parallel, close to Miami, Florida) in the Northern Hemisphere around midnight in the spring.

A star named Mimosa

Crux, the Southern Cross constellation, lies deep in southern skies. Its 2nd-brightest star, Beta Crucis, bears a couple of nicknames, including Mimosa and Becrux. (The constellation’s brightest star, Alpha Crucis, has the nickname Acrux.) German astronomer Johann Bayer (1572-1625) may have been the one to call it Mimosa. Bayer’s reasoning is unclear, but it might be related to this star’s blue-white color. It could also be in honor of the mimosa flower, although most of those are pink, red or yellow.

Join us in making sure everyone has access to the wonders of astronomy. Donate now!

Northerners’ guide to the Southern Cross

View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, caught the Southern Cross while at its highest point around midnight (its midnight culmination) on March 6, 2021. In April and May, the Southern Cross reaches its highest point in the sky earlier in the evening. Thank you, Prateek!

How to see Beta Crucis

Blue-white Mimosa is the 20th brightest star in all the heavens. It’s the 2nd-brightest star in the constellation Crux the Southern Cross. The Cross is a Southern Hemisphere constellation, and you will not see Mimosa north of 30 degrees north latitude. Some cities near 30 degrees north latitude are Austin, Texas; Cairo, Egypt; and New Delhi, India. Southern Hemisphere observers know and love Mimosa, though, and it is circumpolar for latitudes of about 30 degrees south and higher.

A midnight culmination occurs when a star is roughly opposite the sun. It ensures that the star will be above the horizon a maximum amount of time. This occurs for Mimosa on or about April 2 each year.

It stays above the horizon year-round for observers in the Southern Hemisphere, but it can be seen by those in the southern reaches of the Northern Hemisphere for a short time each year. For example, observers in southerly latitudes around Miami, Florida (around 26 degrees north latitude and farther south), can view the Southern Cross and Mimosa on May evenings as it appears just above the southern horizon.

The nearer the observer is to the northern observation limit of about 30 degrees, the lower the star will climb into the sky and the shorter the time it will be visible. For example, from Austin, the star barely skirts the horizon for about a half hour at most. Often it can’t be seen at all due to the dimming affects of Earth’s atmosphere. From Miami it rises almost 5 degrees above the horizon and stays up more than four hours.

From Northern Hemisphere locations such as Hawaii, where Mimosa can be seen more easily, it rises in the late evening in late winter, far to the south-southeast, and sets in the predawn hours to the south-southwest. By early June it rises before sundown and sets by midnight.

History and mythology of Mimosa

Because of its southerly location, Crux and Mimosa were essentially unknown in classical western mythology. Of course, these stars were well known to the Australian Aboriginal peoples as well as the islanders of Polynesia and the people of southern Africa.

In Australia, for example, one Aboriginal story is that the stars of the Southern Cross are a reminder of the time and place where death first came to mankind. Two of the stars are the glowing eyes of the spirit of death, and the other two are the eyes of the first man to die.

The main stars of Crux, including Mimosa, appear on the flags of both Australia and New Zealand. Mimosa appears as the left side of the crossbar, and Acrux as the bottom of the Cross.

See flags featuring the stars of the Southern Cross

View at EarthSky Community Photos. | Kannan A in Woodlands, Singapore, captured this photo of the Southern Cross – and the star Mimosa – on March 8, 2021. He wrote: “The Southern Cross constellation seen here in the morning in Singapore looking south. On the left of this cross are the 2 pointer stars, Alpha Centauri (Rigel Kentaurus) and Beta Centauri (Hadar). They point to the Southern Cross.” Thanks, Kannan!

The science of Beta Crucis

Mimosa lies about 350 light-years from Earth, according to data obtained by the Hipparcos mission. It has a visual magnitude of 1.25. Mimosa is a giant (or subgiant) blue star, more than 3,000 times brighter than our sun in visible light.

Mimosa is blue and very hot. Astronomer James Kaler has estimated its temperature at nearly 28,000 kelvin (about 50,000 degrees F or 27,700 degrees C) at the surface. Such high temperatures demand that much of the the star’s energy be radiated in ultraviolet and higher frequencies invisible to the human eye. So, when you take this into account, Mimosa is about 34,000 times more energetic than the sun, according to Kaler.

Mimosa has a radius about eight times that of the sun, with a mass 14 times greater. However, these figures are uncertain. The reason? Mimosa has a small stellar companion about which little is known. Since all we can observe is the combined light of both, it’s difficult to be precise on the details. The star also is a complex variable star with three short periodicities in its light, which varies less than a 20th of a magnitude over several hours.

Directly south of Mimosa is the Coalsack, a distinctive dark nebula in the Milky Way. The famous Jewel Box Cluster lies to Mimosa’s east.

Position of Mimosa (Beta Crucis) is RA: 12h 47m 44s, dec: -59° 41′ 19″.

Bottom line: Mimosa is the 2nd-brightest star in Crux, the Southern Cross. Always visible from the Southern Hemisphere, Mimosa can be seen from southerly Northern Hemisphere locations.

Acrux is brightest star in Southern Cross

Southern Cross: Signpost of southern skies

How to see the Southern Cross from the Northern Hemisphere

The post Mimosa, 2nd-brightest star in Crux, the Southern Cross first appeared on EarthSky.

from EarthSky https://ift.tt/ILF9ClQ

Crux, the Southern Cross, and its major stars. Mimosa is on the left near the Jewel Box Cluster. This is the view from a southerly latitude (around 25 degrees north parallel, close to Miami, Florida) in the Northern Hemisphere around midnight in the spring.

A star named Mimosa

Crux, the Southern Cross constellation, lies deep in southern skies. Its 2nd-brightest star, Beta Crucis, bears a couple of nicknames, including Mimosa and Becrux. (The constellation’s brightest star, Alpha Crucis, has the nickname Acrux.) German astronomer Johann Bayer (1572-1625) may have been the one to call it Mimosa. Bayer’s reasoning is unclear, but it might be related to this star’s blue-white color. It could also be in honor of the mimosa flower, although most of those are pink, red or yellow.

Join us in making sure everyone has access to the wonders of astronomy. Donate now!

Northerners’ guide to the Southern Cross

View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, caught the Southern Cross while at its highest point around midnight (its midnight culmination) on March 6, 2021. In April and May, the Southern Cross reaches its highest point in the sky earlier in the evening. Thank you, Prateek!

How to see Beta Crucis

Blue-white Mimosa is the 20th brightest star in all the heavens. It’s the 2nd-brightest star in the constellation Crux the Southern Cross. The Cross is a Southern Hemisphere constellation, and you will not see Mimosa north of 30 degrees north latitude. Some cities near 30 degrees north latitude are Austin, Texas; Cairo, Egypt; and New Delhi, India. Southern Hemisphere observers know and love Mimosa, though, and it is circumpolar for latitudes of about 30 degrees south and higher.

A midnight culmination occurs when a star is roughly opposite the sun. It ensures that the star will be above the horizon a maximum amount of time. This occurs for Mimosa on or about April 2 each year.

It stays above the horizon year-round for observers in the Southern Hemisphere, but it can be seen by those in the southern reaches of the Northern Hemisphere for a short time each year. For example, observers in southerly latitudes around Miami, Florida (around 26 degrees north latitude and farther south), can view the Southern Cross and Mimosa on May evenings as it appears just above the southern horizon.

The nearer the observer is to the northern observation limit of about 30 degrees, the lower the star will climb into the sky and the shorter the time it will be visible. For example, from Austin, the star barely skirts the horizon for about a half hour at most. Often it can’t be seen at all due to the dimming affects of Earth’s atmosphere. From Miami it rises almost 5 degrees above the horizon and stays up more than four hours.

From Northern Hemisphere locations such as Hawaii, where Mimosa can be seen more easily, it rises in the late evening in late winter, far to the south-southeast, and sets in the predawn hours to the south-southwest. By early June it rises before sundown and sets by midnight.

History and mythology of Mimosa

Because of its southerly location, Crux and Mimosa were essentially unknown in classical western mythology. Of course, these stars were well known to the Australian Aboriginal peoples as well as the islanders of Polynesia and the people of southern Africa.

In Australia, for example, one Aboriginal story is that the stars of the Southern Cross are a reminder of the time and place where death first came to mankind. Two of the stars are the glowing eyes of the spirit of death, and the other two are the eyes of the first man to die.

The main stars of Crux, including Mimosa, appear on the flags of both Australia and New Zealand. Mimosa appears as the left side of the crossbar, and Acrux as the bottom of the Cross.

See flags featuring the stars of the Southern Cross

View at EarthSky Community Photos. | Kannan A in Woodlands, Singapore, captured this photo of the Southern Cross – and the star Mimosa – on March 8, 2021. He wrote: “The Southern Cross constellation seen here in the morning in Singapore looking south. On the left of this cross are the 2 pointer stars, Alpha Centauri (Rigel Kentaurus) and Beta Centauri (Hadar). They point to the Southern Cross.” Thanks, Kannan!

The science of Beta Crucis

Mimosa lies about 350 light-years from Earth, according to data obtained by the Hipparcos mission. It has a visual magnitude of 1.25. Mimosa is a giant (or subgiant) blue star, more than 3,000 times brighter than our sun in visible light.

Mimosa is blue and very hot. Astronomer James Kaler has estimated its temperature at nearly 28,000 kelvin (about 50,000 degrees F or 27,700 degrees C) at the surface. Such high temperatures demand that much of the the star’s energy be radiated in ultraviolet and higher frequencies invisible to the human eye. So, when you take this into account, Mimosa is about 34,000 times more energetic than the sun, according to Kaler.

Mimosa has a radius about eight times that of the sun, with a mass 14 times greater. However, these figures are uncertain. The reason? Mimosa has a small stellar companion about which little is known. Since all we can observe is the combined light of both, it’s difficult to be precise on the details. The star also is a complex variable star with three short periodicities in its light, which varies less than a 20th of a magnitude over several hours.

Directly south of Mimosa is the Coalsack, a distinctive dark nebula in the Milky Way. The famous Jewel Box Cluster lies to Mimosa’s east.

Position of Mimosa (Beta Crucis) is RA: 12h 47m 44s, dec: -59° 41′ 19″.

Bottom line: Mimosa is the 2nd-brightest star in Crux, the Southern Cross. Always visible from the Southern Hemisphere, Mimosa can be seen from southerly Northern Hemisphere locations.

Acrux is brightest star in Southern Cross

Southern Cross: Signpost of southern skies

How to see the Southern Cross from the Northern Hemisphere

The post Mimosa, 2nd-brightest star in Crux, the Southern Cross first appeared on EarthSky.

from EarthSky https://ift.tt/ILF9ClQ

Auroras last night from ‘extreme’ solar storm wow millions

View at EarthSky Community Photos. | Julie Lanter in Claryville, Kentucky, caught the aurora on May 10, 2024. Julie wrote: “The aurora borealis? In Kentucky? What a rare, unexpected sight!” Thank you, Julie!

Auroras last night!

On Friday, May 10, 2024, space weather forecasters began predicting a “severe” solar storm. When it came, it was even stronger than predicted, at “extreme” levels. So many people saw amazing displays of auroras last night from places at latitudes as low as Mexico, the Bahamas, western Africa, New Zealand, Australia, Chile and Argentina. Wonderful that so many got to see it! And the images came pouring in. The ones on this page are just a taste of what we received at EarthSky Community Photos, and in our social media feeds. Thank you to all who submitted photos! What a night!

The geomagnetic storming was due to no less than five coronal mass ejections (CMEs) that left the sun this week, during a flurry of X flares. These chunks of sun material struck Earth’s magnetic field, causing the fantastic auroral display. And the solar storm is still happening! Read the sun news for tonight’s prospects.

Why did the solar storms happen? The overall reason is that the sun is reaching the peak of its 11-year cycle of activity. This cycle is called Solar Cycle 25. Watch our livestream from last Monday – a conversation with EarthSky founder Deborah Byrd and NASA heliophysicist C. Alex Young – on why the sun has been blasting so many X flares.Submit your photo to EarthSky Community Photos here

Marty Curran in Cheyenne, Wyoming captured this stunning view of the auroras last night (night of May 10-11, 2024) from an extreme solar storm. Thank you, Marty!

View at EarthSky Community Photos. | Aurora as seen from Cheyenne, Wyoming, early on May 11, 2024, by Marcy Curran. Marcy wrote: “What an incredible geomagnetic storm. This is with my cell phone from our deck. I am glad my husband woke me up and said, ‘You need to see this.'” Thank you, Marcy.

View at EarthSky Community Photos. | Roy Trugler captured the aurora from Little Sebago Lake, Gray, Maine, on May 10, 2024. Roy wrote: “Northern lights in Maine.” Thank you, Roy!

Paul Scott Anderson caught the aurora on May 10, 2024, from Vancouver, Canada. Paul wrote: “I’m starting to see the auroras more easily by eye, too. Even better in iPhone night mode!” Thank you, Paul.

View at EarthSky Community Photos. | Patricia Evans caught the aurora over Nubble Lighthouse in Cape Neddick, Maine, on May 10, 2024. Patricia wrote: “I watched as the ripples of color changed and danced across the sky. It was so much fun to hear all the ‘oooohs’ and ‘ahhhhs’ and oh wows from fellow onlookers!” Thank you, Patricia!

Marcy Curran captured the aurora on May 10, 2024, from Cheyenne, Wyoming. Thank you, Marcy!

View at EarthSky Community Photos. | David Hawkes in Sheffield, UK, caught the aurora on May 11, 2024. David wrote: “I had read about possible Aurora tonight in the UK due to the various CMEs hitting earth and thought maybe there was a chance of seeing something. Not something I’ve witnessed before, so one off the bucket list! What a light show!” Thank you, David.

View at EarthSky Community Photos. | Daniel Wiegert caught this view of the May 10-11, 2024, aurora from Glommen, Sweden. Daniel wrote: “I have never experienced auroras towards the south at this latitude before. Most action was in the southwestern direction (and straight up).” Thank you, Daniel!

View at EarthSky Community Photos. | Chuck Reinhart in Vincennes, Indiana, caught the aurora on May 10, 2024. Chuck wrote: “This is a view of the Northern Lights from my yard in Vincennes, Indiana. The camera’s sensor records colors the eye can’t see.” Thank you, Chuck!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

EarthSky’s Kelly Kizer Whitt captured this photo of the aurora just in front of a lightning storm in Madison, Wisconsin. Thanks, Kelly!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

EarthSky’s Raúl Cortes captured this image from Zacatecas, Mexico on May 10, 2024. Thanks. Raúl!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

Bottom line: Auroras last night (night of May 10-11, 2024) from “extreme” geomagnetic storming – which came after a week of very high activity on the sun – wowed millions around the globe.

The post Auroras last night from ‘extreme’ solar storm wow millions first appeared on EarthSky.

from EarthSky https://ift.tt/ERUGKkf

View at EarthSky Community Photos. | Julie Lanter in Claryville, Kentucky, caught the aurora on May 10, 2024. Julie wrote: “The aurora borealis? In Kentucky? What a rare, unexpected sight!” Thank you, Julie!

Auroras last night!

On Friday, May 10, 2024, space weather forecasters began predicting a “severe” solar storm. When it came, it was even stronger than predicted, at “extreme” levels. So many people saw amazing displays of auroras last night from places at latitudes as low as Mexico, the Bahamas, western Africa, New Zealand, Australia, Chile and Argentina. Wonderful that so many got to see it! And the images came pouring in. The ones on this page are just a taste of what we received at EarthSky Community Photos, and in our social media feeds. Thank you to all who submitted photos! What a night!

The geomagnetic storming was due to no less than five coronal mass ejections (CMEs) that left the sun this week, during a flurry of X flares. These chunks of sun material struck Earth’s magnetic field, causing the fantastic auroral display. And the solar storm is still happening! Read the sun news for tonight’s prospects.

Why did the solar storms happen? The overall reason is that the sun is reaching the peak of its 11-year cycle of activity. This cycle is called Solar Cycle 25. Watch our livestream from last Monday – a conversation with EarthSky founder Deborah Byrd and NASA heliophysicist C. Alex Young – on why the sun has been blasting so many X flares.Submit your photo to EarthSky Community Photos here

Marty Curran in Cheyenne, Wyoming captured this stunning view of the auroras last night (night of May 10-11, 2024) from an extreme solar storm. Thank you, Marty!

View at EarthSky Community Photos. | Aurora as seen from Cheyenne, Wyoming, early on May 11, 2024, by Marcy Curran. Marcy wrote: “What an incredible geomagnetic storm. This is with my cell phone from our deck. I am glad my husband woke me up and said, ‘You need to see this.'” Thank you, Marcy.

View at EarthSky Community Photos. | Roy Trugler captured the aurora from Little Sebago Lake, Gray, Maine, on May 10, 2024. Roy wrote: “Northern lights in Maine.” Thank you, Roy!

Paul Scott Anderson caught the aurora on May 10, 2024, from Vancouver, Canada. Paul wrote: “I’m starting to see the auroras more easily by eye, too. Even better in iPhone night mode!” Thank you, Paul.

View at EarthSky Community Photos. | Patricia Evans caught the aurora over Nubble Lighthouse in Cape Neddick, Maine, on May 10, 2024. Patricia wrote: “I watched as the ripples of color changed and danced across the sky. It was so much fun to hear all the ‘oooohs’ and ‘ahhhhs’ and oh wows from fellow onlookers!” Thank you, Patricia!

Marcy Curran captured the aurora on May 10, 2024, from Cheyenne, Wyoming. Thank you, Marcy!

View at EarthSky Community Photos. | David Hawkes in Sheffield, UK, caught the aurora on May 11, 2024. David wrote: “I had read about possible Aurora tonight in the UK due to the various CMEs hitting earth and thought maybe there was a chance of seeing something. Not something I’ve witnessed before, so one off the bucket list! What a light show!” Thank you, David.

View at EarthSky Community Photos. | Daniel Wiegert caught this view of the May 10-11, 2024, aurora from Glommen, Sweden. Daniel wrote: “I have never experienced auroras towards the south at this latitude before. Most action was in the southwestern direction (and straight up).” Thank you, Daniel!

View at EarthSky Community Photos. | Chuck Reinhart in Vincennes, Indiana, caught the aurora on May 10, 2024. Chuck wrote: “This is a view of the Northern Lights from my yard in Vincennes, Indiana. The camera’s sensor records colors the eye can’t see.” Thank you, Chuck!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Will Triggs captured this photo of the aurora from just east of London, UK on May 10, 2024. Thanks, Will!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

EarthSky’s Kelly Kizer Whitt captured this photo of the aurora just in front of a lightning storm in Madison, Wisconsin. Thanks, Kelly!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

EarthSky’s Raúl Cortes captured this image from Zacatecas, Mexico on May 10, 2024. Thanks. Raúl!

EarthSky’s Theresa Wiegert captured this photo from Brockville, Canada, on March 10, 2024. Thanks, Theresa!

Bottom line: Auroras last night (night of May 10-11, 2024) from “extreme” geomagnetic storming – which came after a week of very high activity on the sun – wowed millions around the globe.

The post Auroras last night from ‘extreme’ solar storm wow millions first appeared on EarthSky.

from EarthSky https://ift.tt/ERUGKkf

Orangutan treats his wound with a medicinal plant

For the first time, scientists have witnessed an animal treating its wounds with a medicinal plant. Cognitive and evolutionary biologists from the Max Planck Institute of Animal Behavior in Germany and Universitas Nasional in Indonesia said on May 2, 2024, that they were observing a Sumatran orangutan named Rakus when they saw him apply a plant with medicinal properties to a wound on his face. The orangutan ate a plant with known anti-inflammatory and pain-relieving properties. He also applied the sap and green plant mesh directly to his wound. It’s the first documentation of wound treatment by an animal with a biologically active substance.

The researchers published their study on May 2, 2024, in the peer-reviewed journal Nature, Scientific Reports.

Join us in our mission to educate and inspire people about the universe. Your donation can make a difference in astronomy and contribute to our growth and sustainability.

Animal self-medication

This is Rakus, a Sumatran orangutan that treated his own wound with a medicinal plant. Image via Armas/ Suaq Project.

Scientists have witnessed various sick and avoidance behaviors in animals before. Researchers have even seen animals ingest plant parts as a form of self-medication. But this type of wound treatment is new.

Sometimes orangutans accidentally touch plants while they’re feeding. It turns out that some of these plants have analgesic effects. So, as orangutans feel an immediate relief to the pain, they tend to repeat the same procedure, thereby treating their injuries.

Caroline Schuppli, one of the authors of the study, wrote:

Individuals may accidentally touch their wounds while feeding on this plant and thus unintentionally apply the plant’s juice to their wounds. As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times.

How this orangutan treated himself

Rakus had a wound on his face below his eye. It was probably the result of a fight with another male. But he took good care of it, like our early ancestors would have.

Rakus took some leaves from a climbing plant with the common name Akar Kuning (Fibraurea tinctoria). Then he chewed on them and precisely applied the sap to his wound several times. But that’s not all. This new doctor also fully covered the wound with the chewed leaves, protecting it from getting infected.

Isabelle Laumer, from the Max Planck Institute of Animal Behavior, and first author of the study, wrote about the plant:

This and related liana species that can be found in tropical forests of Southeast Asia are known for their analgesic and antipyretic effects and are used in traditional medicine to treat various diseases, such as malaria. Analyses of plant chemical compounds show the presence of furanoditerpenoids and protoberberine alkaloids, which are known to have antibacterial, anti-inflammatory, anti-fungal, antioxidant and other biological activities of relevance to wound healing.

So, Rakus did an excellent job because the wound healed and was completely closed in just five days, without infection. Also, Rakus rested more than usual while injured. Laumer explained:

Sleep positively affects wound healing, as growth hormone release, protein synthesis and cell division are increased during sleep.

Is Rakus the first orangutan of his kind?

Now, an interesting question comes to mind … If Rakus the Sumatran orangutan was aware of this plant’s properties and knew how to apply it to his wound, do other members of his species know about the treatment, too? Do they also possess this intentional behavior? According to Lamer:

The behavior of Rakus appeared to be intentional as he selectively treated his facial wound on his right flange, and no other body parts, with the plant juice. The behavior was also repeated several times, not only with the plant juice but also later with more solid plant material until the wound was fully covered. The entire process took a considerable amount of time.

The study took place at the Suaq Balimbing research site in Indonesia, which is a protected rainforest area. The sanctuary is home to approximately 150 critically endangered Sumatran orangutans. Scientists hadn’t observed this behavior before in the Suaq orangutan population. But, none of the Sumatran orangutans are born in Suaq. Schuppli explained:

Orangutan males disperse from their natal area during or after puberty over long distances to either establish a new home range in another area or are moving between other’s home ranges.

Schuppli added:

Therefore, it is possible that the behavior is shown by more individuals in his natal population outside the Suaq research area.

One smart ape, or many?

Only time and more studies will confirm if Rakus is a genius or if more great apes are capable of healing their wounds in this way. Apes already ingest specific plants to treat parasite infections and rub the plants on their skin to treat sore muscles. So maybe this is their next evolutionary step.

Orangutans are quite smart and can learn from watching their moms. Some of the skills they learn include where to find food, what to eat and how to eat it. They also learn how to build a proper sleeping nest. And some of these skills involve using special tools. It wouldn’t be surprising to see this behavior more often in the coming decades.

Bottom line: In a first, a Sumatran orangutan treated his wound with a plant with known medicinal properties. Read more about this new doctor in the forest.

Sources: Active self-treatment of a facial wound with a biologically active plant by a male Sumatran orangutan

Via Max-Planck-Gesellschaft

Read more: Tyrannosaurus rex not so smart, after all

The post Orangutan treats his wound with a medicinal plant first appeared on EarthSky.

from EarthSky https://ift.tt/L63hNqZ

For the first time, scientists have witnessed an animal treating its wounds with a medicinal plant. Cognitive and evolutionary biologists from the Max Planck Institute of Animal Behavior in Germany and Universitas Nasional in Indonesia said on May 2, 2024, that they were observing a Sumatran orangutan named Rakus when they saw him apply a plant with medicinal properties to a wound on his face. The orangutan ate a plant with known anti-inflammatory and pain-relieving properties. He also applied the sap and green plant mesh directly to his wound. It’s the first documentation of wound treatment by an animal with a biologically active substance.

The researchers published their study on May 2, 2024, in the peer-reviewed journal Nature, Scientific Reports.

Join us in our mission to educate and inspire people about the universe. Your donation can make a difference in astronomy and contribute to our growth and sustainability.

Animal self-medication

This is Rakus, a Sumatran orangutan that treated his own wound with a medicinal plant. Image via Armas/ Suaq Project.

Scientists have witnessed various sick and avoidance behaviors in animals before. Researchers have even seen animals ingest plant parts as a form of self-medication. But this type of wound treatment is new.

Sometimes orangutans accidentally touch plants while they’re feeding. It turns out that some of these plants have analgesic effects. So, as orangutans feel an immediate relief to the pain, they tend to repeat the same procedure, thereby treating their injuries.

Caroline Schuppli, one of the authors of the study, wrote:

Individuals may accidentally touch their wounds while feeding on this plant and thus unintentionally apply the plant’s juice to their wounds. As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times.

How this orangutan treated himself

Rakus had a wound on his face below his eye. It was probably the result of a fight with another male. But he took good care of it, like our early ancestors would have.

Rakus took some leaves from a climbing plant with the common name Akar Kuning (Fibraurea tinctoria). Then he chewed on them and precisely applied the sap to his wound several times. But that’s not all. This new doctor also fully covered the wound with the chewed leaves, protecting it from getting infected.

Isabelle Laumer, from the Max Planck Institute of Animal Behavior, and first author of the study, wrote about the plant:

This and related liana species that can be found in tropical forests of Southeast Asia are known for their analgesic and antipyretic effects and are used in traditional medicine to treat various diseases, such as malaria. Analyses of plant chemical compounds show the presence of furanoditerpenoids and protoberberine alkaloids, which are known to have antibacterial, anti-inflammatory, anti-fungal, antioxidant and other biological activities of relevance to wound healing.

So, Rakus did an excellent job because the wound healed and was completely closed in just five days, without infection. Also, Rakus rested more than usual while injured. Laumer explained:

Sleep positively affects wound healing, as growth hormone release, protein synthesis and cell division are increased during sleep.

Is Rakus the first orangutan of his kind?

Now, an interesting question comes to mind … If Rakus the Sumatran orangutan was aware of this plant’s properties and knew how to apply it to his wound, do other members of his species know about the treatment, too? Do they also possess this intentional behavior? According to Lamer:

The behavior of Rakus appeared to be intentional as he selectively treated his facial wound on his right flange, and no other body parts, with the plant juice. The behavior was also repeated several times, not only with the plant juice but also later with more solid plant material until the wound was fully covered. The entire process took a considerable amount of time.

The study took place at the Suaq Balimbing research site in Indonesia, which is a protected rainforest area. The sanctuary is home to approximately 150 critically endangered Sumatran orangutans. Scientists hadn’t observed this behavior before in the Suaq orangutan population. But, none of the Sumatran orangutans are born in Suaq. Schuppli explained:

Orangutan males disperse from their natal area during or after puberty over long distances to either establish a new home range in another area or are moving between other’s home ranges.

Schuppli added:

Therefore, it is possible that the behavior is shown by more individuals in his natal population outside the Suaq research area.

One smart ape, or many?

Only time and more studies will confirm if Rakus is a genius or if more great apes are capable of healing their wounds in this way. Apes already ingest specific plants to treat parasite infections and rub the plants on their skin to treat sore muscles. So maybe this is their next evolutionary step.

Orangutans are quite smart and can learn from watching their moms. Some of the skills they learn include where to find food, what to eat and how to eat it. They also learn how to build a proper sleeping nest. And some of these skills involve using special tools. It wouldn’t be surprising to see this behavior more often in the coming decades.

Bottom line: In a first, a Sumatran orangutan treated his wound with a plant with known medicinal properties. Read more about this new doctor in the forest.

Sources: Active self-treatment of a facial wound with a biologically active plant by a male Sumatran orangutan

Via Max-Planck-Gesellschaft

Read more: Tyrannosaurus rex not so smart, after all

The post Orangutan treats his wound with a medicinal plant first appeared on EarthSky.

from EarthSky https://ift.tt/L63hNqZ

Vega is a bright bluish star on May evenings

The 3 brightest stars in this image make up the asterism of the Summer Triangle, a giant triangle in the sky composed of the bright stars Vega (top left), Altair (lower middle) and Deneb (far left). Also in this image, under a dark sky and on a moonless night, is the Great Rift that passes right through the Summer Triangle. Image via NASA/ A. Fujii/ ESA.

Vega shines brightly on May evenings

Look for Vega tonight. It’s the 5th brightest star in our sky. If you’re in the Northern Hemisphere, you’ll find beautiful, bluish Vega easily, simply by looking northeastward at mid-evening in May. Vega is so bright that you can see it on a moonlit night.

From far south in the Southern Hemisphere, you can’t see Vega until late at night in May. That’s because Vega is located so far north on the sky’s dome. Vega will reach its high point for the night around three to four hours after midnight, at which time people in the Southern Hemisphere can see Vega in their northern sky. As seen from mid-northern latitudes, Vega shines high overhead at this early morning hour.

Because it’s the brightest star in the constellation Lyra the Harp, Vega is sometimes called the Harp Star. Like all stars, Vega rises some four minutes earlier each day as Earth moves around the sun. So, Vega will adorn our evening sky throughout the summer and fall.

Join our community of passionate astronomy enthusiasts and help us continue to bring you the latest astronomy news and insights. Your donation makes it all possible.

It’s visible most nights from mid-northern latitudes

Although Vega is considered a late spring or summer star, it’s actually so far north on the sky’s dome that – from mid-latitudes in the Northern Hemisphere – you can find it at some time during the night, nearly every night of the year.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

View at EarthSky Community Photos. | Here’s Vega (and Lyra) as seen around 3 a.m. from Valencia, Philippines, on May 10, 2019, from our friend Dr Ski. See Vega’s beautiful blue color? Notice the star near Vega, marked with the Greek letter Epsilon. This star is Epsilon Lyrae, a famous double-double star.

Bottom line: If you’re in the Northern Hemisphere, Vega is easy to identify in its constellation Lyra at this time of year. Just look northeast in the evening hours for a bright, bluish star above the northeastern horizon.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.

The post Vega is a bright bluish star on May evenings first appeared on EarthSky.

from EarthSky https://ift.tt/d7hyMKk

The 3 brightest stars in this image make up the asterism of the Summer Triangle, a giant triangle in the sky composed of the bright stars Vega (top left), Altair (lower middle) and Deneb (far left). Also in this image, under a dark sky and on a moonless night, is the Great Rift that passes right through the Summer Triangle. Image via NASA/ A. Fujii/ ESA.

Vega shines brightly on May evenings

Look for Vega tonight. It’s the 5th brightest star in our sky. If you’re in the Northern Hemisphere, you’ll find beautiful, bluish Vega easily, simply by looking northeastward at mid-evening in May. Vega is so bright that you can see it on a moonlit night.

From far south in the Southern Hemisphere, you can’t see Vega until late at night in May. That’s because Vega is located so far north on the sky’s dome. Vega will reach its high point for the night around three to four hours after midnight, at which time people in the Southern Hemisphere can see Vega in their northern sky. As seen from mid-northern latitudes, Vega shines high overhead at this early morning hour.

Because it’s the brightest star in the constellation Lyra the Harp, Vega is sometimes called the Harp Star. Like all stars, Vega rises some four minutes earlier each day as Earth moves around the sun. So, Vega will adorn our evening sky throughout the summer and fall.

Join our community of passionate astronomy enthusiasts and help us continue to bring you the latest astronomy news and insights. Your donation makes it all possible.

It’s visible most nights from mid-northern latitudes

Although Vega is considered a late spring or summer star, it’s actually so far north on the sky’s dome that – from mid-latitudes in the Northern Hemisphere – you can find it at some time during the night, nearly every night of the year.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

View at EarthSky Community Photos. | Here’s Vega (and Lyra) as seen around 3 a.m. from Valencia, Philippines, on May 10, 2019, from our friend Dr Ski. See Vega’s beautiful blue color? Notice the star near Vega, marked with the Greek letter Epsilon. This star is Epsilon Lyrae, a famous double-double star.

Bottom line: If you’re in the Northern Hemisphere, Vega is easy to identify in its constellation Lyra at this time of year. Just look northeast in the evening hours for a bright, bluish star above the northeastern horizon.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.

The post Vega is a bright bluish star on May evenings first appeared on EarthSky.

from EarthSky https://ift.tt/d7hyMKk

Polaris – the North Star – is the present-day North Star

View at EarthSky Community Photos. | Radu Anghel in Motoseni, Romania, wrote: “A bright Perseid meteor and a Polaris star trail from August 13, 2023. I set up the camera pointing at Polaris, and after that I just enjoyed the celestial show with family and friends until the morning.” Beautiful, Radu! Thank you.

Don’t wait for it to set

The North Star or Pole Star – aka Polaris – is famous for holding nearly still in our sky while the entire northern sky moves around it. That’s because it’s located very close to the north celestial pole, the point around which the entire northern sky turns. Although it’s a common belief, Polaris is not the brightest star in the nighttime sky. In fact, it’s only the 48th brightest star. But you can find it easily, and, once you do, you’ll see it shining in the northern sky every night from Northern Hemisphere locations.

Polaris marks the spot that is due north. As you face Polaris and stretch your arms sideways, your right hand points due east, and your left hand points due west. Then, an about-face from Polaris steers you due south.

Star trails shown circling around Polaris, the North Star. Image via Goodfreephotos.com/ Unsplash. Used with permission.

Help spread the wonders of astronomy! Please donate now to EarthSky.org and ensure that people around the world can learn about the night sky and our universe.

A star to steer by

In a dark country sky, even when the full moon obscures a good deal of the starry heavens, the North Star is relatively easy to see. That fact has made this star a boon to travelers throughout the Northern Hemisphere, both over land and sea. So finding Polaris means you know the direction north.

Best of all, you can readily find Polaris by using the prominent group of stars known as the Big Dipper, called the Plough in the United Kingdom, which may be the Northern Hemisphere’s most famous star pattern. To locate Polaris, all you have to do is to find the Big Dipper pointer stars Dubhe and Merak. These two stars outline the outer part of the Big Dipper’s bowl. Simply draw a line from Merak through Dubhe, and go about five times the Merak/Dubhe distance to Polaris.

If you can find the Big Dipper, you can find Polaris. The two outer stars in the bowl of the Dipper – Dubhe and Merak – always point to the North Star.

This clock runs backward

The Big Dipper, like a great big hour hand, goes full circle around Polaris in one day. More specifically, the Big Dipper circles Polaris in a counterclockwise direction in 23 hours and 56 minutes. Although the Big Dipper travels around Polaris all night long, the Big Dipper pointer stars always point to Polaris at any time of the night, and on any day of the year. Polaris marks the center of nature’s grandest celestial clock!

It’s part of the Little Dipper

By the way, Polaris is famous for more reasons than one. It’s famous for hardly moving while the other stars wheel around it. And it’s famous for marking the end of the Little Dipper‘s handle. The Little Dipper is tougher to spot in the night sky than the Big Dipper. But if you use the Big Dipper’s pointer stars to locate Polaris, you’ll be one step closer to seeing the Little Dipper.

The Big Dipper leads you to the Little Dipper. Polaris marks the end of the handle of the Little Dipper.

Its height in the sky depends on your location

As you travel northward, Polaris climbs higher in the sky. If you go as far north as the North Pole, you’ll see Polaris directly overhead.

As you travel south, Polaris drops closer to the northern horizon.

If you get as far as the equator, Polaris sinks to the horizon.

South of the equator, Polaris drops below the northern horizon.

History of Polaris

Polaris hasn’t always been the North Star and won’t remain the North Star forever. For example, a famous star called Thuban, in the constellation Draco the Dragon, was the North Star when the Egyptians built the pyramids.

But Polaris is a good North Star because it’s the sky’s 48th brightest star. So it’s noticeable in the sky. It served well as the North Star, for example, when the Europeans first sailed across the Atlantic over five centuries ago.

And Polaris will continue its reign as the North Star for many centuries to come. It will align most closely with the north celestial pole – the point in the sky directly above Earth’s north rotational axis – on March 24, 2100. The computational wizard Jean Meeus figures Polaris will be 27′ 09″ (0.4525 degrees) from the north celestial pole at that time (a little less than the angular diameter of the moon when at its farthest from Earth).

Meanwhile, there is currently no visible star marking the celestial pole in the Southern Hemisphere. What’s more, the Southern Hemisphere won’t see a pole star appreciably close to the south celestial pole for another 2,000 years.

Trusting Polaris with their lives

At one time in human history, people literally depended on their lucky stars for their lives and livelihood. Luckily, they could trust the Big Dipper and the North Star to guide them. People could sail the seas and cross the trackless deserts without getting lost. When slavery existed in the United States, people escaping slavery counted on the Big Dipper to show them the North Star, lighting their way to the free states and Canada.

While being honored as the North Star, Polaris enjoys the title of Lodestar and Cynosure as well.

Polaris is a triple star

The single point of light that we see as Polaris is a triple star system, or three stars orbiting a common center of mass. The primary star, Polaris A, is a supergiant with about six times the mass of our sun. A close companion, Polaris Ab, orbits 2 billion miles from Polaris. You are unlikely to ever see this star, because it is too close to Polaris.

Much farther away, near the top of this illustration, is the third companion, Polaris B. Polaris B, magnitude 8.7, is located approximately 240 billion miles from Polaris A. This translates to 18.4 arcseconds, and you can split these two stars in a small telescope. This split is always a hit at public star parties. The two companion stars are the same temperature as Polaris A but are dwarf stars.

Artist’s concept of Polaris and its two known companion stars. Image via NASA/ Wikimedia Commons (public domain).

Star bright, star light

Astronomers estimate Polaris’ distance at 434 light-years. Considering the distance, Polaris must be a respectably luminous star. Polaris is a yellow supergiant star shining with the luminosity of 1,260 suns.

And it varies in brightness, too!

Polaris is a variable star. In the past, it had varied between magnitudes 1.86 and 2.13 every four days. In recent decades, this variability decreased from 10% to 2%, then it went back up to 4% variability. Astronomers are not sure why this happened. It’s the type of variable star known as a Cepheid variable star, a class of stars that astronomers use to figure distances to star clusters and galaxies.

Seeing Polaris in a telescope during the day

Since Polaris hardly moves, this makes it easy to see in the daytime. Set your telescope on Polaris in the early morning, before dawn. Focus sharply on it. Turn off your clock drive, if you have one, and keep your telescope stationary. Come back just after sunrise and look for it again. It should still be in your field of view, having moved about 30 arcminutes in the past three hours.

What’s the RA today?

In the year 2000, Polaris’ position was RA: 2h 31m 48.7s, dec: +89° 15′ 51″. Due to precession, since this star is so close to the celestial north pole, its Right Ascension (RA) can change quickly. Presently it is sitting at about 03h 00m. Here is a graph showing how the RA of the star changes over the next century.

The right ascension of Polaris for the next century. Graph by Don Machholz using data from Stub Mandrel.

The view of Polaris you will never see: the Integrated Flux Nebula

Just when you think you have seen it all … maybe you have. Because this next bit will blow your mind, and you will never visually see it. Below we see an image of Polaris, which is several images stacked to bring out the contrast. Those are not clouds in our atmosphere. They are not clouds between us and Polaris. They are clouds well beyond Polaris, illuminated by the light of our galaxy. These clouds are called the Integrated Flux Nebula. I am not making this up: see here.

An example of the faint integrated flux nebula around the star Polaris. Image via Kush Chandaria/ Wikipedia (CC BY-SA 4.0).

Bottom line: Polaris is the North Star, and the entire northern sky wheels around it. But it’s not the brightest star in the sky. In fact, Polaris ranks only 48th in brightness.

Read more: Does Mars have a North Star?

Read more: Does the North Star ever move?

The post Polaris – the North Star – is the present-day North Star first appeared on EarthSky.

from EarthSky https://ift.tt/Pwj6xYU

View at EarthSky Community Photos. | Radu Anghel in Motoseni, Romania, wrote: “A bright Perseid meteor and a Polaris star trail from August 13, 2023. I set up the camera pointing at Polaris, and after that I just enjoyed the celestial show with family and friends until the morning.” Beautiful, Radu! Thank you.

Don’t wait for it to set

The North Star or Pole Star – aka Polaris – is famous for holding nearly still in our sky while the entire northern sky moves around it. That’s because it’s located very close to the north celestial pole, the point around which the entire northern sky turns. Although it’s a common belief, Polaris is not the brightest star in the nighttime sky. In fact, it’s only the 48th brightest star. But you can find it easily, and, once you do, you’ll see it shining in the northern sky every night from Northern Hemisphere locations.

Polaris marks the spot that is due north. As you face Polaris and stretch your arms sideways, your right hand points due east, and your left hand points due west. Then, an about-face from Polaris steers you due south.

Star trails shown circling around Polaris, the North Star. Image via Goodfreephotos.com/ Unsplash. Used with permission.

Help spread the wonders of astronomy! Please donate now to EarthSky.org and ensure that people around the world can learn about the night sky and our universe.

A star to steer by

In a dark country sky, even when the full moon obscures a good deal of the starry heavens, the North Star is relatively easy to see. That fact has made this star a boon to travelers throughout the Northern Hemisphere, both over land and sea. So finding Polaris means you know the direction north.

Best of all, you can readily find Polaris by using the prominent group of stars known as the Big Dipper, called the Plough in the United Kingdom, which may be the Northern Hemisphere’s most famous star pattern. To locate Polaris, all you have to do is to find the Big Dipper pointer stars Dubhe and Merak. These two stars outline the outer part of the Big Dipper’s bowl. Simply draw a line from Merak through Dubhe, and go about five times the Merak/Dubhe distance to Polaris.

If you can find the Big Dipper, you can find Polaris. The two outer stars in the bowl of the Dipper – Dubhe and Merak – always point to the North Star.

This clock runs backward

The Big Dipper, like a great big hour hand, goes full circle around Polaris in one day. More specifically, the Big Dipper circles Polaris in a counterclockwise direction in 23 hours and 56 minutes. Although the Big Dipper travels around Polaris all night long, the Big Dipper pointer stars always point to Polaris at any time of the night, and on any day of the year. Polaris marks the center of nature’s grandest celestial clock!

It’s part of the Little Dipper

By the way, Polaris is famous for more reasons than one. It’s famous for hardly moving while the other stars wheel around it. And it’s famous for marking the end of the Little Dipper‘s handle. The Little Dipper is tougher to spot in the night sky than the Big Dipper. But if you use the Big Dipper’s pointer stars to locate Polaris, you’ll be one step closer to seeing the Little Dipper.

The Big Dipper leads you to the Little Dipper. Polaris marks the end of the handle of the Little Dipper.

Its height in the sky depends on your location

As you travel northward, Polaris climbs higher in the sky. If you go as far north as the North Pole, you’ll see Polaris directly overhead.

As you travel south, Polaris drops closer to the northern horizon.

If you get as far as the equator, Polaris sinks to the horizon.

South of the equator, Polaris drops below the northern horizon.

History of Polaris

Polaris hasn’t always been the North Star and won’t remain the North Star forever. For example, a famous star called Thuban, in the constellation Draco the Dragon, was the North Star when the Egyptians built the pyramids.

But Polaris is a good North Star because it’s the sky’s 48th brightest star. So it’s noticeable in the sky. It served well as the North Star, for example, when the Europeans first sailed across the Atlantic over five centuries ago.

And Polaris will continue its reign as the North Star for many centuries to come. It will align most closely with the north celestial pole – the point in the sky directly above Earth’s north rotational axis – on March 24, 2100. The computational wizard Jean Meeus figures Polaris will be 27′ 09″ (0.4525 degrees) from the north celestial pole at that time (a little less than the angular diameter of the moon when at its farthest from Earth).

Meanwhile, there is currently no visible star marking the celestial pole in the Southern Hemisphere. What’s more, the Southern Hemisphere won’t see a pole star appreciably close to the south celestial pole for another 2,000 years.

Trusting Polaris with their lives

At one time in human history, people literally depended on their lucky stars for their lives and livelihood. Luckily, they could trust the Big Dipper and the North Star to guide them. People could sail the seas and cross the trackless deserts without getting lost. When slavery existed in the United States, people escaping slavery counted on the Big Dipper to show them the North Star, lighting their way to the free states and Canada.

While being honored as the North Star, Polaris enjoys the title of Lodestar and Cynosure as well.

Polaris is a triple star

The single point of light that we see as Polaris is a triple star system, or three stars orbiting a common center of mass. The primary star, Polaris A, is a supergiant with about six times the mass of our sun. A close companion, Polaris Ab, orbits 2 billion miles from Polaris. You are unlikely to ever see this star, because it is too close to Polaris.

Much farther away, near the top of this illustration, is the third companion, Polaris B. Polaris B, magnitude 8.7, is located approximately 240 billion miles from Polaris A. This translates to 18.4 arcseconds, and you can split these two stars in a small telescope. This split is always a hit at public star parties. The two companion stars are the same temperature as Polaris A but are dwarf stars.

Artist’s concept of Polaris and its two known companion stars. Image via NASA/ Wikimedia Commons (public domain).

Star bright, star light

Astronomers estimate Polaris’ distance at 434 light-years. Considering the distance, Polaris must be a respectably luminous star. Polaris is a yellow supergiant star shining with the luminosity of 1,260 suns.

And it varies in brightness, too!

Polaris is a variable star. In the past, it had varied between magnitudes 1.86 and 2.13 every four days. In recent decades, this variability decreased from 10% to 2%, then it went back up to 4% variability. Astronomers are not sure why this happened. It’s the type of variable star known as a Cepheid variable star, a class of stars that astronomers use to figure distances to star clusters and galaxies.

Seeing Polaris in a telescope during the day

Since Polaris hardly moves, this makes it easy to see in the daytime. Set your telescope on Polaris in the early morning, before dawn. Focus sharply on it. Turn off your clock drive, if you have one, and keep your telescope stationary. Come back just after sunrise and look for it again. It should still be in your field of view, having moved about 30 arcminutes in the past three hours.

What’s the RA today?

In the year 2000, Polaris’ position was RA: 2h 31m 48.7s, dec: +89° 15′ 51″. Due to precession, since this star is so close to the celestial north pole, its Right Ascension (RA) can change quickly. Presently it is sitting at about 03h 00m. Here is a graph showing how the RA of the star changes over the next century.

The right ascension of Polaris for the next century. Graph by Don Machholz using data from Stub Mandrel.

The view of Polaris you will never see: the Integrated Flux Nebula

Just when you think you have seen it all … maybe you have. Because this next bit will blow your mind, and you will never visually see it. Below we see an image of Polaris, which is several images stacked to bring out the contrast. Those are not clouds in our atmosphere. They are not clouds between us and Polaris. They are clouds well beyond Polaris, illuminated by the light of our galaxy. These clouds are called the Integrated Flux Nebula. I am not making this up: see here.

An example of the faint integrated flux nebula around the star Polaris. Image via Kush Chandaria/ Wikipedia (CC BY-SA 4.0).

Bottom line: Polaris is the North Star, and the entire northern sky wheels around it. But it’s not the brightest star in the sky. In fact, Polaris ranks only 48th in brightness.

Read more: Does Mars have a North Star?

Read more: Does the North Star ever move?

The post Polaris – the North Star – is the present-day North Star first appeared on EarthSky.

from EarthSky https://ift.tt/Pwj6xYU

Plunge into a black hole in this new video

See what it’s like to plunge into a black hole in this new NASA video.

Plunge into a black hole in new video

Have you ever wondered what happens when you fall into a black hole? On May 6, 2024, a NASA supercomputer produced a new, immersive visualization that lets viewers plunge into the event horizon. That’s a black hole’s point of no return.

Jeremy Schnittman is an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and created the visualizations. Schnittman said:

People often ask about this, and simulating these difficult-to-imagine processes helps me connect the mathematics of relativity to actual consequences in the real universe. So I simulated two different scenarios, one where a camera – a stand-in for a daring astronaut – just misses the event horizon and slingshots back out, and one where it crosses the boundary, sealing its fate.

To create the visualizations, Schnittman teamed up with fellow Goddard scientist Brian Powell and used the Discover supercomputer at the NASA Center for Climate Simulation. The project generated about 10 terabytes of data. As an illustration, that’s equivalent to roughly half of the estimated text content in the Library of Congress. And the simulation took about five days running on just 0.3% of Discover’s 129,000 processors. In fact, the same feat would take more than a decade on a typical laptop.

Attention astronomy enthusiasts! Are you looking for a way to show your support for astronomy education? Donate to EarthSky.org here and help us bring knowledge of the night sky and our universe to people worldwide. Thank you!

A simulated black hole

The destination is a supermassive black hole with 4.3 million times the mass of our sun. That size is equivalent to the monster located at the center of our Milky Way galaxy.

Schnittman explained:

If you have the choice, you want to fall into a supermassive black hole. Stellar-mass black holes, which contain up to about 30 solar masses, possess much smaller event horizons and stronger tidal forces, which can rip apart approaching objects before they get to the horizon.

This occurs because the gravitational pull on the end of an object nearer the black hole is much stronger than that on the other end. Infalling objects stretch out like noodles, a process astrophysicists call spaghettification.

The simulated black hole’s event horizon spans about 16 million miles (26 million km). That’s about 17% of the distance from Earth to the sun. A flat, swirling cloud of hot, glowing gas called an accretion disk surrounds the black hole. The accretion disk serves as a visual reference during the fall. So do glowing structures called photon rings. They form closer to the black hole from light that has orbited it one or more times. A backdrop of the starry sky as seen from Earth completes the scene.

The plunge

As the camera approaches the black hole, it reaches speeds ever closer to that of light itself. You can see the glow from the accretion disk and background stars become amplified. The increase in brightness occurs in much the same way as the sound of an oncoming racecar rises in pitch. The light appears brighter and whiter when looking into the direction of travel.

The movies begin with the camera located nearly 400 million miles (640 million km) away. Then, the black hole quickly begins filling the view. Along the way, the black hole’s disk, photon rings and the night sky become increasingly distorted. They even form multiple images as their light traverses the increasingly warped space-time.

In real time, the camera takes about three hours to fall to the event horizon, executing almost two complete 30-minute orbits along the way. But to anyone observing from afar, it would never quite get there. As space-time became ever more distorted closer to the horizon, the image of the camera would slow and then seem to freeze just shy of it. This is why astronomers originally referred to black holes as frozen stars.

At the event horizon, even space-time itself flows inward at the speed of light, the cosmic speed limit. Once inside it, both the camera and the space-time in which it’s moving rush toward the black hole’s center. That center is a one-dimensional point called a singularity, where the laws of physics as we know them cease to operate. Schnittman said:

Once the camera crosses the horizon, its destruction by spaghettification is just 12.8 seconds away.

From there, it’s only 79,500 miles (128,000 km) to the singularity. This final leg of the voyage is over in the blink of an eye.

Orbiting without getting sucked in

In the alternative scenario (below), the camera orbits close to the event horizon but it never crosses over and escapes to safety. Imagine if an astronaut flew a spacecraft on this 6-hour round trip while her colleagues on a mothership remained far from the black hole. She’d return 36 minutes younger than the colleagues. That’s because time passes more slowly near a strong gravitational source and when moving near the speed of light.

Schnittman noted:

This situation can be even more extreme. If the black hole were rapidly rotating, like the one shown in the 2014 movie Interstellar, she would return many years younger than her shipmates.

Bottom line: Plunge into a black hole in this new video from NASA. See what it would look like to cross the event horizon of a supermassive black hole.

Via NASA

The post Plunge into a black hole in this new video first appeared on EarthSky.

from EarthSky https://ift.tt/4K8eHyj

See what it’s like to plunge into a black hole in this new NASA video.

Plunge into a black hole in new video

Have you ever wondered what happens when you fall into a black hole? On May 6, 2024, a NASA supercomputer produced a new, immersive visualization that lets viewers plunge into the event horizon. That’s a black hole’s point of no return.

Jeremy Schnittman is an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and created the visualizations. Schnittman said:

People often ask about this, and simulating these difficult-to-imagine processes helps me connect the mathematics of relativity to actual consequences in the real universe. So I simulated two different scenarios, one where a camera – a stand-in for a daring astronaut – just misses the event horizon and slingshots back out, and one where it crosses the boundary, sealing its fate.

To create the visualizations, Schnittman teamed up with fellow Goddard scientist Brian Powell and used the Discover supercomputer at the NASA Center for Climate Simulation. The project generated about 10 terabytes of data. As an illustration, that’s equivalent to roughly half of the estimated text content in the Library of Congress. And the simulation took about five days running on just 0.3% of Discover’s 129,000 processors. In fact, the same feat would take more than a decade on a typical laptop.

Attention astronomy enthusiasts! Are you looking for a way to show your support for astronomy education? Donate to EarthSky.org here and help us bring knowledge of the night sky and our universe to people worldwide. Thank you!

A simulated black hole

The destination is a supermassive black hole with 4.3 million times the mass of our sun. That size is equivalent to the monster located at the center of our Milky Way galaxy.

Schnittman explained:

If you have the choice, you want to fall into a supermassive black hole. Stellar-mass black holes, which contain up to about 30 solar masses, possess much smaller event horizons and stronger tidal forces, which can rip apart approaching objects before they get to the horizon.

This occurs because the gravitational pull on the end of an object nearer the black hole is much stronger than that on the other end. Infalling objects stretch out like noodles, a process astrophysicists call spaghettification.

The simulated black hole’s event horizon spans about 16 million miles (26 million km). That’s about 17% of the distance from Earth to the sun. A flat, swirling cloud of hot, glowing gas called an accretion disk surrounds the black hole. The accretion disk serves as a visual reference during the fall. So do glowing structures called photon rings. They form closer to the black hole from light that has orbited it one or more times. A backdrop of the starry sky as seen from Earth completes the scene.

The plunge

As the camera approaches the black hole, it reaches speeds ever closer to that of light itself. You can see the glow from the accretion disk and background stars become amplified. The increase in brightness occurs in much the same way as the sound of an oncoming racecar rises in pitch. The light appears brighter and whiter when looking into the direction of travel.

The movies begin with the camera located nearly 400 million miles (640 million km) away. Then, the black hole quickly begins filling the view. Along the way, the black hole’s disk, photon rings and the night sky become increasingly distorted. They even form multiple images as their light traverses the increasingly warped space-time.

In real time, the camera takes about three hours to fall to the event horizon, executing almost two complete 30-minute orbits along the way. But to anyone observing from afar, it would never quite get there. As space-time became ever more distorted closer to the horizon, the image of the camera would slow and then seem to freeze just shy of it. This is why astronomers originally referred to black holes as frozen stars.

At the event horizon, even space-time itself flows inward at the speed of light, the cosmic speed limit. Once inside it, both the camera and the space-time in which it’s moving rush toward the black hole’s center. That center is a one-dimensional point called a singularity, where the laws of physics as we know them cease to operate. Schnittman said:

Once the camera crosses the horizon, its destruction by spaghettification is just 12.8 seconds away.

From there, it’s only 79,500 miles (128,000 km) to the singularity. This final leg of the voyage is over in the blink of an eye.

Orbiting without getting sucked in

In the alternative scenario (below), the camera orbits close to the event horizon but it never crosses over and escapes to safety. Imagine if an astronaut flew a spacecraft on this 6-hour round trip while her colleagues on a mothership remained far from the black hole. She’d return 36 minutes younger than the colleagues. That’s because time passes more slowly near a strong gravitational source and when moving near the speed of light.

Schnittman noted:

This situation can be even more extreme. If the black hole were rapidly rotating, like the one shown in the 2014 movie Interstellar, she would return many years younger than her shipmates.

Bottom line: Plunge into a black hole in this new video from NASA. See what it would look like to cross the event horizon of a supermassive black hole.

Via NASA

The post Plunge into a black hole in this new video first appeared on EarthSky.

from EarthSky https://ift.tt/4K8eHyj