New study says residential trees can affect human health

A view from above of Interlaken, Switzerland. A new study analyzed residential trees and mortality in Switzerland. Image via Kelly Kizer Whitt.

• Urban trees enhance residents’ well-being. A long-term Switzerland-wide study has found that neighborhoods with numerous, well-arranged trees exhibit lower mortality risks than other areas.
• Aggregated, connected tree clusters seem to provide greater health benefits than fragmented green spaces at the neighborhood level.
• In fact, the study identified a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies.

ETH Zurich published this original story on March 20, 2025. Edits by EarthSky.

Residential trees benefit human health

Beyond creating a serene and open atmosphere in urban areas, trees and parks also contribute to human well-being. There are various reasons for this: trees filter pollutants out of the air, provide shade, lower the ambient temperature in hot weather and encourage people to spend more time outdoors. Many governments have set ambitious tree-planting targets for the decades ahead, partly in response to climate change and rising temperatures. In densely developed cities, however, space for new green space is at a premium. In this context, the key question is how to plant trees in existing green spaces to optimal effect.

This is a question that occupies urban planning researchers and practitioners alike, because any answer must take into account specific, local spatial circumstances and climatic conditions. ETH researchers are tackling this issue … not only in Switzerland, but also in Asia. In the course of their work, researchers from Future Cities Lab operated in Singapore by ETH Zurich and the National University of Singapore (NUS) discovered interesting links between tree management and the health of urban residents.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Data analysis on over 6 million people

To begin with, the researchers examined high-resolution tree canopy data to determine the structure of tree-covered green spaces within a radius of 500 meters (1,640 feet) of a person’s place of residence. In addition to recording the total area covered by all tree clusters, they also identified the proximity and connectedness of tree clusters, their geometrical complexity and the fragmentation level.

They linked this information with the survival time of the residents in the respective neighborhood for over 6 million adults. That is, they looked exclusively at natural-cause deaths due to illness and old age. The Swiss Federal Statistical Office supplied this data, which covers a 10-year period (2010–2019). In order to protect privacy, the Federal Statistical Office rounded the coordinates of citizens’ residences to the nearest 50 meters (164 feet).

A view of Lauterbrunnen, Switzerland. Image via Kelly Kizer Whitt.

Residential trees: quantity and positioning both matter

The analysis showed that both the tree canopy cover in residential areas and their spatial arrangement correlate with mortality. The study identified a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies. That’s versus people who live in areas with fewer, fragmented areas of tree canopies with complex geometries. This correlation is particularly evident in densely developed peri-urban and urban areas with poor air quality and high temperatures. If such areas feature well-structured forested green spaces, the residents may receive more health benefits than other areas.

Yet, while this study represents an important first step, it is still not possible to draw conclusions regarding the causes. The researchers are not yet able to state with precision the pathways through which tree canopy configuration influences human health. Nevertheless, the study’s findings at the individual level are generally consistent with the results of similar studies at the community level in Philadelphia, Tehran and Taipei.

Isolated forested green spaces should be joined up

Dengkai Chi, a postdoctoral researcher at the ETH Future Cities Lab and the first author of the study, said:

Although we can’t yet define a direct causal link, when we have addressed factors such as age, gender and socio-economic status, the data show clear correlations. Our results provide plausible indications that human health may be influenced not only by the quantity of trees but also by their spatial distribution.

The findings underline the importance of carefully considering the layout of forested green spaces and adopting a targeted approach to tree placement. Chi said:

In order to fully exploit trees’ potential to support human health, cities should strive to not only increase the number of trees but also to connect isolated green spaces, including by creating tree-lined boulevards.

The study also suggested that compact, geometrically simple areas of tree canopy – including circular and rectangular forms – could have a greater positive effect on health than irregular, fragmented tree coverage. One possible explanation is that simply structured areas offer a larger core area, promote biodiversity and consequently attract residents to use these spaces.

Dengkai Chi of ETH Zurich was the lead author of the study. Image via ETH Zurich.

Further research and clear indicators needed

Chi explained:

We’re still at the very outset of this research.

The study was unable to take account of many specific influencing factors, such as whether people have preexisting illnesses, smoke or actually use green spaces. In addition, the results of this study pertain to the neighborhood level. They do not necessarily translate to an entire municipal area. Initial indications suggest that, at the level of an entire city, the health-promoting effects of green spaces correlate with their more even distribution throughout the city. That way, as many residents as possible have access to them. The researchers hope to examine these issues in further studies to better understand these links.

Chi explained that, when it comes to developing recommendations for future action by political decision-makers and urban planners, the researchers will have to quantify their results more effectively and define specific thresholds.

Bottom line: A new study examined residential trees in Switzerland and found a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies.

Source: Residential tree canopy configuration and mortality in 6 million Swiss adults: a longitudinal study

Via ETH Zurich

The post New study says residential trees can affect human health first appeared on EarthSky.

from EarthSky https://ift.tt/uNHwirn

A view from above of Interlaken, Switzerland. A new study analyzed residential trees and mortality in Switzerland. Image via Kelly Kizer Whitt.

• Urban trees enhance residents’ well-being. A long-term Switzerland-wide study has found that neighborhoods with numerous, well-arranged trees exhibit lower mortality risks than other areas.
• Aggregated, connected tree clusters seem to provide greater health benefits than fragmented green spaces at the neighborhood level.
• In fact, the study identified a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies.

ETH Zurich published this original story on March 20, 2025. Edits by EarthSky.

Residential trees benefit human health

Beyond creating a serene and open atmosphere in urban areas, trees and parks also contribute to human well-being. There are various reasons for this: trees filter pollutants out of the air, provide shade, lower the ambient temperature in hot weather and encourage people to spend more time outdoors. Many governments have set ambitious tree-planting targets for the decades ahead, partly in response to climate change and rising temperatures. In densely developed cities, however, space for new green space is at a premium. In this context, the key question is how to plant trees in existing green spaces to optimal effect.

This is a question that occupies urban planning researchers and practitioners alike, because any answer must take into account specific, local spatial circumstances and climatic conditions. ETH researchers are tackling this issue … not only in Switzerland, but also in Asia. In the course of their work, researchers from Future Cities Lab operated in Singapore by ETH Zurich and the National University of Singapore (NUS) discovered interesting links between tree management and the health of urban residents.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Data analysis on over 6 million people

To begin with, the researchers examined high-resolution tree canopy data to determine the structure of tree-covered green spaces within a radius of 500 meters (1,640 feet) of a person’s place of residence. In addition to recording the total area covered by all tree clusters, they also identified the proximity and connectedness of tree clusters, their geometrical complexity and the fragmentation level.

They linked this information with the survival time of the residents in the respective neighborhood for over 6 million adults. That is, they looked exclusively at natural-cause deaths due to illness and old age. The Swiss Federal Statistical Office supplied this data, which covers a 10-year period (2010–2019). In order to protect privacy, the Federal Statistical Office rounded the coordinates of citizens’ residences to the nearest 50 meters (164 feet).

A view of Lauterbrunnen, Switzerland. Image via Kelly Kizer Whitt.

Residential trees: quantity and positioning both matter

The analysis showed that both the tree canopy cover in residential areas and their spatial arrangement correlate with mortality. The study identified a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies. That’s versus people who live in areas with fewer, fragmented areas of tree canopies with complex geometries. This correlation is particularly evident in densely developed peri-urban and urban areas with poor air quality and high temperatures. If such areas feature well-structured forested green spaces, the residents may receive more health benefits than other areas.

Yet, while this study represents an important first step, it is still not possible to draw conclusions regarding the causes. The researchers are not yet able to state with precision the pathways through which tree canopy configuration influences human health. Nevertheless, the study’s findings at the individual level are generally consistent with the results of similar studies at the community level in Philadelphia, Tehran and Taipei.

Isolated forested green spaces should be joined up

Dengkai Chi, a postdoctoral researcher at the ETH Future Cities Lab and the first author of the study, said:

Although we can’t yet define a direct causal link, when we have addressed factors such as age, gender and socio-economic status, the data show clear correlations. Our results provide plausible indications that human health may be influenced not only by the quantity of trees but also by their spatial distribution.

The findings underline the importance of carefully considering the layout of forested green spaces and adopting a targeted approach to tree placement. Chi said:

In order to fully exploit trees’ potential to support human health, cities should strive to not only increase the number of trees but also to connect isolated green spaces, including by creating tree-lined boulevards.

The study also suggested that compact, geometrically simple areas of tree canopy – including circular and rectangular forms – could have a greater positive effect on health than irregular, fragmented tree coverage. One possible explanation is that simply structured areas offer a larger core area, promote biodiversity and consequently attract residents to use these spaces.

Dengkai Chi of ETH Zurich was the lead author of the study. Image via ETH Zurich.

Further research and clear indicators needed

Chi explained:

We’re still at the very outset of this research.

The study was unable to take account of many specific influencing factors, such as whether people have preexisting illnesses, smoke or actually use green spaces. In addition, the results of this study pertain to the neighborhood level. They do not necessarily translate to an entire municipal area. Initial indications suggest that, at the level of an entire city, the health-promoting effects of green spaces correlate with their more even distribution throughout the city. That way, as many residents as possible have access to them. The researchers hope to examine these issues in further studies to better understand these links.

Chi explained that, when it comes to developing recommendations for future action by political decision-makers and urban planners, the researchers will have to quantify their results more effectively and define specific thresholds.

Bottom line: A new study examined residential trees in Switzerland and found a significantly lower mortality risk in people who live in neighborhoods with large, contiguous and well-networked areas of tree canopies.

Source: Residential tree canopy configuration and mortality in 6 million Swiss adults: a longitudinal study

Via ETH Zurich

The post New study says residential trees can affect human health first appeared on EarthSky.

from EarthSky https://ift.tt/uNHwirn

Asteroid 2024 YR4 won’t hit in 2032, but it will be back

The faint dot fixed in the center of this starfield is asteroid 2024 YR4. This is a sequence of observations from ESO’s Very Large Telescope in January 2025, shortly after the asteroid was discovered to have a greater than 3% chance of hitting Earth in 2032. Further observations have revealed that this asteroid won’t hit us in the foreseeable future. But, owing to a specific orbital resonance, it – and others – will keep coming back into our vicinity. Via Wikimedia Commons/ ESO/ O. Hainaut et al.

• Astronomers have determined that asteroid 2024 YR4 will not hit Earth in 2032, as had been feared.
• But asteroids like this one will keep coming back regularly, thanks to a strange orbital resonance.
• These dangerous space rocks sit in an orbital “Kirkwood gap,” populated by asteroids that are pushed and pulled by Jupiter’s gravity until they either leave their orbit or hit a planet like Earth.

By Martin Connors, Athabasca University. Edits by EarthSky.

Asteroids like 2024 YR4 will keep coming back

In late 2024, astronomers spotted asteroid 2024 YR4 on a trajectory that could potentially threaten Earth. This observation triggered a fervid series of observations to determine that the object, which is large enough to cause city-level damage, will not hit.

Then in January of this year, the near approach of asteroid 887 Alinda – perhaps a million times more massive than 2024 YR4 – went almost unnoticed. This asteroid is large enough to cause a global extinction event.

Alinda remains just outside Earth’s orbit, while 2024 YR4 continues to cross our orbit and still could impact Earth, although not in the foreseeable future. But, thanks to a strange orbital resonance, these asteroids are of a variety that will come back worryingly regularly. That is, until they’re ejected from their orbit … or until they collide with a planet like Earth.

A radar image of asteroid 887 Alinda taken in January 2024. The rectangular region at the top of the asteroid is about 3 kilometers (2 miles) a side. Image via NASA/ JPL.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Asteroids 2024 YR4 and 887 Alinda have dangerous orbits

Both 887 Alinda and 2024 YR4 orbit the sun three times for every time the massive planet Jupiter goes around once. Since Jupiter’s orbit takes 12 years, the asteroids will take four years to be back on similar paths in 2028. This special kind of asteroids is dangerous, since they come back regularly.

Alinda was discovered in 1918 and has made several sequences of near passes at four-year intervals. 2024 YR4 has made what NASA considers close passes every four years since 1948, but was only recently noticed.

Not since the 1970s has so much attention been paid to asteroids with a three-to-one orbital relation to Jupiter. Such relationships had already been noted as a curiosity by American astronomer Daniel Kirkwood in the late 1800s. Working with very sparse data, since few asteroids were known at the time, he noted that none went around the sun twice for each Jupiter orbit, nor three times, nor in more complex ratios like seven-to-three or five-to-two.

These statistical voids are known as Kirkwood gaps. And they’re not obvious, as they only show up when you plot the average distance of asteroids from the sun. The gaps remained a mere curiosity of the solar system for about 100 years.

This chart shows asteroid quantities by averaged distance from the sun, showing the Kirkwood gaps. The gap labelled 3:1 harbors both 887 Alinda and 2024 YR4, located at an average distance 2.5 times Earth’s distance from the sun. Chart via NASA/ JPL.

Understanding the Kirkwood gaps

The use of new computer technologies to calculate orbits revealed the effects of resonance to scientists in the 1970s. Resonance occurs when asteroids appear to move at the same speed that an external object orbits, or a multiple of the speed. In this case, that external object is the gravitationally dominant gas giant Jupiter.

The Kirkwood gaps are explained by asteroids interacting with Jupiter to leave the asteroid belt, even while their average distance from the sun does not change. That is, their orbits become more elliptical or oval-shaped, so they dip farther in and then farther out of the asteroid belt during each single orbit of the sun.

By dipping into the inner solar system, these asteroids are often removed by hitting an inner planet like Mars, Venus or Earth. And that’s one reason there are very few asteroids remaining with these particular orbits. Alternatively, if they don’t hit an inner planet, their orbits can become so elongated that they escape the solar system. Or Jupiter’s gravity can simply move them to a different, more stable orbit.

However, scientists have found that these Kirkwood gaps are not completely empty. They discovered 887 Alinda, for example, in the three-to-one gap. Many more such asteroids have been found, and they are generically named “Alindas” after that first discovery.

Asteroids 2024 YR4 and 887 Alinda will keep returning

So the bad news is that Kirkwood gaps are partly due to asteroids hitting inner planets, including Earth. Can it get much worse? For Alinda-class asteroids, it does. Alindas follow their pumped-up, elongated orbit every four years. So certain Alindas get a chance to hit Earth about that often.

Near passes of these asteroids tend to happen spaced by gradually longer intervals. But when perfectly aligned, they come back several times with four-year spacing. A limiting factor is how tilted their orbits are. If they are quite tilted, they are not often at a “height” matching Earth’s, so are less likely to hit.

The bad news about that is that both 887 Alinda and 2024 YR4 are very nearly in the plane of Earth’s orbit, and are not tilted much, so are more likely to hit.

The resonant “pumping” that stretches the orbit both inward and outward from the asteroid belt has already made 2024 YR4 cross Earth’s orbit, giving it a chance to impact. The much more dangerous Alinda is still being pumped; in about 1,000 years, it may be poised to hit Earth.

One piece of good news is that 2024 YR4 will not only miss in 2032, but it will come close enough that our planet’s gravity will kick it out of its Alinda orbit. It will no longer come back every four years.

However, its orbit will still cross ours, just not as often. The current orbit shows a somewhat close approach (farther than the moon) in 2052. Beyond that calculations are not very accurate.

Earth impacts

Although Earth is a small target in a big solar system, it does get hit.

Are dangerous asteroids out there likely to surprise us? The last damaging one to do so appeared undetected on February 15, 2013, over Chelyabinsk, Russia, injuring many people when its shock wave shattered glass in buildings.

In 1908, a larger explosion took place over Tunguska, Russian Siberia, a remote region where huge areas of forest were devastated but few people injured.

Fallen trees from the 1908 Tunguska explosion in Siberia. Photo via the Soviet Academy of Science/ NASA/ Leonid Kulik/ Yevgeny Krinov.

Keeping watch

While astronomers work diligently to survey the night sky from Earth’s surface, space-based surveys like the upcoming Near-Earth Object (NEO) surveyor can be very efficient in detecting asteroids. The NEO surveyor will do so by watching for the heat (infrared) radiation of asteroids. And, being in space, the satellite can also study the daytime sky.

According to Amy Mainzer, lead on the NEO surveyor:

We know of only roughly 40% of the asteroids that are both large enough to cause severe regional damage and closely approach Earth’s orbit.

Once launched in late 2027, NEO will “find, track and characterize the most hazardous asteroids and comets,” eventually meeting the U.S. Congress-mandated goal of knowing of 90% of them.

Among asteroids, we must pay special attention to resonant ones like 2024 YR4, because – eventually – they’ll be back.

Martin Connors, Professor of Astronomy, Mathematics, and Physics, Athabasca University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Asteroids like 2024 YR4 – which is set to pass very close to Earth in 2032 – will keep coming back into our planet’s vicinity, thanks to a strange orbital resonance.

The post Asteroid 2024 YR4 won’t hit in 2032, but it will be back first appeared on EarthSky.

from EarthSky https://ift.tt/tJrK4Bm

The faint dot fixed in the center of this starfield is asteroid 2024 YR4. This is a sequence of observations from ESO’s Very Large Telescope in January 2025, shortly after the asteroid was discovered to have a greater than 3% chance of hitting Earth in 2032. Further observations have revealed that this asteroid won’t hit us in the foreseeable future. But, owing to a specific orbital resonance, it – and others – will keep coming back into our vicinity. Via Wikimedia Commons/ ESO/ O. Hainaut et al.

• Astronomers have determined that asteroid 2024 YR4 will not hit Earth in 2032, as had been feared.
• But asteroids like this one will keep coming back regularly, thanks to a strange orbital resonance.
• These dangerous space rocks sit in an orbital “Kirkwood gap,” populated by asteroids that are pushed and pulled by Jupiter’s gravity until they either leave their orbit or hit a planet like Earth.

By Martin Connors, Athabasca University. Edits by EarthSky.

Asteroids like 2024 YR4 will keep coming back

In late 2024, astronomers spotted asteroid 2024 YR4 on a trajectory that could potentially threaten Earth. This observation triggered a fervid series of observations to determine that the object, which is large enough to cause city-level damage, will not hit.

Then in January of this year, the near approach of asteroid 887 Alinda – perhaps a million times more massive than 2024 YR4 – went almost unnoticed. This asteroid is large enough to cause a global extinction event.

Alinda remains just outside Earth’s orbit, while 2024 YR4 continues to cross our orbit and still could impact Earth, although not in the foreseeable future. But, thanks to a strange orbital resonance, these asteroids are of a variety that will come back worryingly regularly. That is, until they’re ejected from their orbit … or until they collide with a planet like Earth.

A radar image of asteroid 887 Alinda taken in January 2024. The rectangular region at the top of the asteroid is about 3 kilometers (2 miles) a side. Image via NASA/ JPL.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Asteroids 2024 YR4 and 887 Alinda have dangerous orbits

Both 887 Alinda and 2024 YR4 orbit the sun three times for every time the massive planet Jupiter goes around once. Since Jupiter’s orbit takes 12 years, the asteroids will take four years to be back on similar paths in 2028. This special kind of asteroids is dangerous, since they come back regularly.

Alinda was discovered in 1918 and has made several sequences of near passes at four-year intervals. 2024 YR4 has made what NASA considers close passes every four years since 1948, but was only recently noticed.

Not since the 1970s has so much attention been paid to asteroids with a three-to-one orbital relation to Jupiter. Such relationships had already been noted as a curiosity by American astronomer Daniel Kirkwood in the late 1800s. Working with very sparse data, since few asteroids were known at the time, he noted that none went around the sun twice for each Jupiter orbit, nor three times, nor in more complex ratios like seven-to-three or five-to-two.

These statistical voids are known as Kirkwood gaps. And they’re not obvious, as they only show up when you plot the average distance of asteroids from the sun. The gaps remained a mere curiosity of the solar system for about 100 years.

This chart shows asteroid quantities by averaged distance from the sun, showing the Kirkwood gaps. The gap labelled 3:1 harbors both 887 Alinda and 2024 YR4, located at an average distance 2.5 times Earth’s distance from the sun. Chart via NASA/ JPL.

Understanding the Kirkwood gaps

The use of new computer technologies to calculate orbits revealed the effects of resonance to scientists in the 1970s. Resonance occurs when asteroids appear to move at the same speed that an external object orbits, or a multiple of the speed. In this case, that external object is the gravitationally dominant gas giant Jupiter.

The Kirkwood gaps are explained by asteroids interacting with Jupiter to leave the asteroid belt, even while their average distance from the sun does not change. That is, their orbits become more elliptical or oval-shaped, so they dip farther in and then farther out of the asteroid belt during each single orbit of the sun.

By dipping into the inner solar system, these asteroids are often removed by hitting an inner planet like Mars, Venus or Earth. And that’s one reason there are very few asteroids remaining with these particular orbits. Alternatively, if they don’t hit an inner planet, their orbits can become so elongated that they escape the solar system. Or Jupiter’s gravity can simply move them to a different, more stable orbit.

However, scientists have found that these Kirkwood gaps are not completely empty. They discovered 887 Alinda, for example, in the three-to-one gap. Many more such asteroids have been found, and they are generically named “Alindas” after that first discovery.

Asteroids 2024 YR4 and 887 Alinda will keep returning

So the bad news is that Kirkwood gaps are partly due to asteroids hitting inner planets, including Earth. Can it get much worse? For Alinda-class asteroids, it does. Alindas follow their pumped-up, elongated orbit every four years. So certain Alindas get a chance to hit Earth about that often.

Near passes of these asteroids tend to happen spaced by gradually longer intervals. But when perfectly aligned, they come back several times with four-year spacing. A limiting factor is how tilted their orbits are. If they are quite tilted, they are not often at a “height” matching Earth’s, so are less likely to hit.

The bad news about that is that both 887 Alinda and 2024 YR4 are very nearly in the plane of Earth’s orbit, and are not tilted much, so are more likely to hit.

The resonant “pumping” that stretches the orbit both inward and outward from the asteroid belt has already made 2024 YR4 cross Earth’s orbit, giving it a chance to impact. The much more dangerous Alinda is still being pumped; in about 1,000 years, it may be poised to hit Earth.

One piece of good news is that 2024 YR4 will not only miss in 2032, but it will come close enough that our planet’s gravity will kick it out of its Alinda orbit. It will no longer come back every four years.

However, its orbit will still cross ours, just not as often. The current orbit shows a somewhat close approach (farther than the moon) in 2052. Beyond that calculations are not very accurate.

Earth impacts

Although Earth is a small target in a big solar system, it does get hit.

Are dangerous asteroids out there likely to surprise us? The last damaging one to do so appeared undetected on February 15, 2013, over Chelyabinsk, Russia, injuring many people when its shock wave shattered glass in buildings.

In 1908, a larger explosion took place over Tunguska, Russian Siberia, a remote region where huge areas of forest were devastated but few people injured.

Fallen trees from the 1908 Tunguska explosion in Siberia. Photo via the Soviet Academy of Science/ NASA/ Leonid Kulik/ Yevgeny Krinov.

Keeping watch

While astronomers work diligently to survey the night sky from Earth’s surface, space-based surveys like the upcoming Near-Earth Object (NEO) surveyor can be very efficient in detecting asteroids. The NEO surveyor will do so by watching for the heat (infrared) radiation of asteroids. And, being in space, the satellite can also study the daytime sky.

According to Amy Mainzer, lead on the NEO surveyor:

We know of only roughly 40% of the asteroids that are both large enough to cause severe regional damage and closely approach Earth’s orbit.

Once launched in late 2027, NEO will “find, track and characterize the most hazardous asteroids and comets,” eventually meeting the U.S. Congress-mandated goal of knowing of 90% of them.

Among asteroids, we must pay special attention to resonant ones like 2024 YR4, because – eventually – they’ll be back.

Martin Connors, Professor of Astronomy, Mathematics, and Physics, Athabasca University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Asteroids like 2024 YR4 – which is set to pass very close to Earth in 2032 – will keep coming back into our planet’s vicinity, thanks to a strange orbital resonance.

The post Asteroid 2024 YR4 won’t hit in 2032, but it will be back first appeared on EarthSky.

from EarthSky https://ift.tt/tJrK4Bm

Widespread severe weather expected in east-central US today

Swaths of the U.S. are under a severe weather risk for March 30 and 31, 2025, with thunderstorms and tornadoes anticipated. This composite shows the evolution of a tornado. Image via Jason Weingart/ Wikimedia (CC BY-SA 4.0).

According to the NOAA’s Storm Prediction Center, more than 100 million people in east-central and mid-southern U.S. states face a risk of severe weather today, March 30, 2025. The organization announced yesterday:

A widespread/ substantial severe weather episode is forecast across an area centered on the Ohio/ Mid and Lower Mississippi/ Lower Missouri/ Tennessee River Valleys. Very large hail, damaging winds, and strong tornadoes are expected.

Cities including Indianapolis, Indiana; St. Louis, Missouri; Nashville, Tennessee; and Little Rock, Arkansas, face what the Storm Prediction Center calls an enhanced risk, the third of five risk levels. That means widespread or persistent storms are expected, along with numerous severe storms, which are those capable of producing inch-sized hail (2.5 cm), wind gusts of 58 miles per hour (93 kph) or tornadoes.

This area also faces the possibility of significant severe weather. This is when a storm is capable of producing hail of at least 2 inches (5 cm) in diameter, wind gusts of 75 miles per hour (120 kph), or a tornado that produces damage that ranks at least 2 on the Enhanced Fujita scale.

This is the severe weather outlook for Sunday, March 30. Chart via the Storm Prediction Center.

When will the storms impact you?

Storm timing will vary depending on where you live. The first of two potential waves of thunderstorms is expected early Sunday morning for the western side of the at-risk areas. The line of severe storms could develop as early as late morning or early afternoon, before moving east through the afternoon into the evening. For more specific timing of when storms will impact you, visit the National Weather Service website and enter your location in the top left.

The at-risk areas could also see thunderstorms today. Image via Sebastian V./ Pexels.

What’s causing the severe weather?

A strong low pressure system with an associated cold front is moving across the middle of the United States. Cold air on its northern side is producing snow and freezing rain for South Dakota, Minnesota and Wisconsin. Meanwhile, on the southern side of the low pressure system, warm, moist air is moving north from the Gulf.

As the low pressure gets stronger, a disturbance in the middle and upper levels of the atmosphere will also move through. This, combined with a strong cold front moving into an area that is warm and muggy with the flow from the Gulf, will cause the severe weather. The storms are expected to develop along the cold front through Sunday afternoon and evening.

Continuing severe weather threat

The severe weather threat from this system will move east. On Monday, much of the U.S. south, Mid-Atlantic and northeast face a slight risk (level two out of five) for severe weather. Warm, moist air remains in place across this area, and a strong cold front will create the chance for severe weather as it progresses east.

Monday’s threat will mainly include damaging wind gusts, but isolated tornadoes are possible across the southern U.S. The weather will then likely remain unsettled, and the Storm Prediction Center has already outlined part of the Ohio Valley for the possibility of severe weather again on Wednesday, April 2nd.

On Monday, March 31, the severe weather will have moved east. Chart via the Storm Prediction Center.

Understanding severe weather outlooks

The Storm Prediction Center uses a five level risk category system when forecasting severe weather. The levels are marginal, slight, enhanced, moderate and high.

If your area is outlined in a marginal risk, expect isolated severe storms that are fairly short lived. A slight risk means severe weather is expected, but not widespread. An enhanced risk, which is what millions face today, means more widespread or longer-lasting severe storms are forecast. A moderate risk means widespread severe weather is likely, with storms that could be long-lived and intense, producing large hail, damaging wind gusts and tornadoes. Finally, a high risk means long-lasting, very intense and widespread damage from severe weather is expected. This would include long-track tornadoes, devastating wind gusts and large hail.

View larger. | A breakdown of the severe thunderstorm risk categories. Chart via the Storm Prediction Center.

Watches vs. Warnings

During a risk for severe weather, watches and warnings are issued in order to keep people aware of dangerous weather that could impact them. But do you know the difference between a weather watch and a warning?

A watch is issued typically hours in advance of impending weather. It means conditions are right for a particular weather hazard to occur, but not that it’s currently occurring.

A weather warning means that particular weather hazard is expected to occur soon, or is already happening.

So if a tornado watch is issued, this means the weather conditions are right for a tornado to form during a severe thunderstorm. A tornado warning means that a tornado is expected to develop, or has already developed and been spotted. During a tornado watch you should immediately go to your safe space and wait for the threat to pass.

Chart via NOAA.

Severe Storm Safety

The safest place during a tornado is in a basement or storm shelter. If you don’t have a basement or storm shelter, locate an interior room or closet in the lowest, most central part of your home, away from all outside windows and walls. If you live in an apartment building or high-rise, go to the very bottom floor of your building and again, find an interior room or closet in the center of the building away from outside walls and windows.

If you’re driving, find the closest building to take shelter in, but do not take shelter under an overpass. An overpass can act as a wind tunnel and make the winds much stronger, and you will be at risk of flying debris.

If you live in a mobile home, get out. A mobile home, even with safety straps, cannot withstand winds from the strongest tornadoes and can easily be blown off its foundations. If your mobile home is in a community and has a community center, go there to take shelter. Otherwise, find a trusted neighbor, family member of friend that has either a basement or a safer place to shelter and stay there until the threat has passed. You can find more severe weather safety tips here.

An early severe weather outlook for Wednesday, April 2. Chart via the Storm Prediction Center

Bottom Line: Millions of Americans are under the threat for severe weather Sunday and Monday as a strong cold front moves across the middle part of the United States. Damaging wind gusts, large hail and significant tornadoes are all possible.

The post Widespread severe weather expected in east-central US today first appeared on EarthSky.

from EarthSky https://ift.tt/WDpkGqy

Swaths of the U.S. are under a severe weather risk for March 30 and 31, 2025, with thunderstorms and tornadoes anticipated. This composite shows the evolution of a tornado. Image via Jason Weingart/ Wikimedia (CC BY-SA 4.0).

According to the NOAA’s Storm Prediction Center, more than 100 million people in east-central and mid-southern U.S. states face a risk of severe weather today, March 30, 2025. The organization announced yesterday:

A widespread/ substantial severe weather episode is forecast across an area centered on the Ohio/ Mid and Lower Mississippi/ Lower Missouri/ Tennessee River Valleys. Very large hail, damaging winds, and strong tornadoes are expected.

Cities including Indianapolis, Indiana; St. Louis, Missouri; Nashville, Tennessee; and Little Rock, Arkansas, face what the Storm Prediction Center calls an enhanced risk, the third of five risk levels. That means widespread or persistent storms are expected, along with numerous severe storms, which are those capable of producing inch-sized hail (2.5 cm), wind gusts of 58 miles per hour (93 kph) or tornadoes.

This area also faces the possibility of significant severe weather. This is when a storm is capable of producing hail of at least 2 inches (5 cm) in diameter, wind gusts of 75 miles per hour (120 kph), or a tornado that produces damage that ranks at least 2 on the Enhanced Fujita scale.

This is the severe weather outlook for Sunday, March 30. Chart via the Storm Prediction Center.

When will the storms impact you?

Storm timing will vary depending on where you live. The first of two potential waves of thunderstorms is expected early Sunday morning for the western side of the at-risk areas. The line of severe storms could develop as early as late morning or early afternoon, before moving east through the afternoon into the evening. For more specific timing of when storms will impact you, visit the National Weather Service website and enter your location in the top left.

The at-risk areas could also see thunderstorms today. Image via Sebastian V./ Pexels.

What’s causing the severe weather?

A strong low pressure system with an associated cold front is moving across the middle of the United States. Cold air on its northern side is producing snow and freezing rain for South Dakota, Minnesota and Wisconsin. Meanwhile, on the southern side of the low pressure system, warm, moist air is moving north from the Gulf.

As the low pressure gets stronger, a disturbance in the middle and upper levels of the atmosphere will also move through. This, combined with a strong cold front moving into an area that is warm and muggy with the flow from the Gulf, will cause the severe weather. The storms are expected to develop along the cold front through Sunday afternoon and evening.

Continuing severe weather threat

The severe weather threat from this system will move east. On Monday, much of the U.S. south, Mid-Atlantic and northeast face a slight risk (level two out of five) for severe weather. Warm, moist air remains in place across this area, and a strong cold front will create the chance for severe weather as it progresses east.

Monday’s threat will mainly include damaging wind gusts, but isolated tornadoes are possible across the southern U.S. The weather will then likely remain unsettled, and the Storm Prediction Center has already outlined part of the Ohio Valley for the possibility of severe weather again on Wednesday, April 2nd.

On Monday, March 31, the severe weather will have moved east. Chart via the Storm Prediction Center.

Understanding severe weather outlooks

The Storm Prediction Center uses a five level risk category system when forecasting severe weather. The levels are marginal, slight, enhanced, moderate and high.

If your area is outlined in a marginal risk, expect isolated severe storms that are fairly short lived. A slight risk means severe weather is expected, but not widespread. An enhanced risk, which is what millions face today, means more widespread or longer-lasting severe storms are forecast. A moderate risk means widespread severe weather is likely, with storms that could be long-lived and intense, producing large hail, damaging wind gusts and tornadoes. Finally, a high risk means long-lasting, very intense and widespread damage from severe weather is expected. This would include long-track tornadoes, devastating wind gusts and large hail.

View larger. | A breakdown of the severe thunderstorm risk categories. Chart via the Storm Prediction Center.

Watches vs. Warnings

During a risk for severe weather, watches and warnings are issued in order to keep people aware of dangerous weather that could impact them. But do you know the difference between a weather watch and a warning?

A watch is issued typically hours in advance of impending weather. It means conditions are right for a particular weather hazard to occur, but not that it’s currently occurring.

A weather warning means that particular weather hazard is expected to occur soon, or is already happening.

So if a tornado watch is issued, this means the weather conditions are right for a tornado to form during a severe thunderstorm. A tornado warning means that a tornado is expected to develop, or has already developed and been spotted. During a tornado watch you should immediately go to your safe space and wait for the threat to pass.

Chart via NOAA.

Severe Storm Safety

The safest place during a tornado is in a basement or storm shelter. If you don’t have a basement or storm shelter, locate an interior room or closet in the lowest, most central part of your home, away from all outside windows and walls. If you live in an apartment building or high-rise, go to the very bottom floor of your building and again, find an interior room or closet in the center of the building away from outside walls and windows.

If you’re driving, find the closest building to take shelter in, but do not take shelter under an overpass. An overpass can act as a wind tunnel and make the winds much stronger, and you will be at risk of flying debris.

If you live in a mobile home, get out. A mobile home, even with safety straps, cannot withstand winds from the strongest tornadoes and can easily be blown off its foundations. If your mobile home is in a community and has a community center, go there to take shelter. Otherwise, find a trusted neighbor, family member of friend that has either a basement or a safer place to shelter and stay there until the threat has passed. You can find more severe weather safety tips here.

An early severe weather outlook for Wednesday, April 2. Chart via the Storm Prediction Center

Bottom Line: Millions of Americans are under the threat for severe weather Sunday and Monday as a strong cold front moves across the middle part of the United States. Damaging wind gusts, large hail and significant tornadoes are all possible.

The post Widespread severe weather expected in east-central US today first appeared on EarthSky.

from EarthSky https://ift.tt/WDpkGqy

The Big and Little Dipper: How to find them in the spring

Look for the Big and Little Dipper high in the northern sky on spring evenings. This view is for the Northern Hemisphere. The 2 outer stars in the bowl of the Dipper point to Polaris, the North Star. Polaris marks the end of the handle of the Little Dipper. Chart via EarthSky.

The Big and Little Dipper

The Big Dipper is one of the easiest star patterns to locate in Earth’s sky. It’s visible just about every clear night in the Northern Hemisphere, looking like a big dot-to-dot of a kitchen ladle. As Earth spins, the Big Dipper and its sky neighbor, the Little Dipper, rotate around the North Star, also known as Polaris.

From the northern part of the Northern Hemisphere, the Big and Little Dippers are in the sky continuously. In fact, they are always above your horizon, circling endlessly around Polaris. So given an unobstructed horizon, latitudes north of the 35th parallel (the approximate location of the Mediterranean Sea, Tennessee’s southern border and Kyoto, Japan) can expect to see the Big Dipper at any hour of the night every day of the year.

As for the Little Dipper, it’s circumpolar – always above the horizon – as far south as the Tropic of Cancer (23.5 degrees north latitude).

If you can spot the Big Dipper, then you’re on your way to finding the Little Dipper and the North Star, Polaris, too.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

The Big Dipper rotates around Polaris every night and changes by season

Just remember the old saying: spring up and fall down. So on spring and summer evenings in the Northern Hemisphere, the Big Dipper shines at its highest in the evening sky. Then, on autumn and winter evenings, the Big Dipper sweeps closer to the horizon.

This animation shows the Big Dipper by seasons from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky. Used with permission.

Here’s how to find Polaris and the Little Dipper

Notice that the Big Dipper has two parts, a bowl and a handle. Next, look for the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and they’re known as The Pointers. An imaginary line drawn between them points to Polaris, the North Star. Polaris marks the end of the Little Dipper’s Handle. So, once you have Polaris, you can find the Little Dipper, too … if your sky is dark enough.

So why isn’t the Little Dipper as easy to pick out as the Big Dipper? That’s because the stars between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. As a matter of fact, you’ll need a dark country sky to see all seven of the Little Dipper’s stars.

The Big and Little Dippers are not constellations

Also, the Big Dipper isn’t a constellation. It’s an asterism, or noticeable pattern of stars. The Big Dipper is a clipped version of the constellation Ursa Major the Greater Bear. And the stars of the Big Dipper outline the Bear’s tail and hindquarters.

The Little Dipper is also an asterism. These stars belong to the constellation Ursa Minor the Little Bear.

The Big Dipper will change over time

Astronomers sometimes speak of the fixed stars, but the stars aren’t truly fixed. Stars move in space. Thus the star patterns that we see today as the Big and Little Dippers will, slowly but surely, drift apart over time.

But even 25,000 years from now, the Big Dipper pattern will look nearly the same as it does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.

In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the video below:

Star lore behind the Big and Little Dipper

In the star lore of the Mi’kmaq nation in northern Canada, the Big Dipper is also associated with a bear, but with a twist. The Mi’kmaq see the bowl of the Big Dipper as a Celestial Bear, and the three stars of the handle as hunters chasing the Bear. In the Mi’kmaq tale of the Celestial Bear, in autumn the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autumn landscape

In another version of the story, the Celestial Bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When the Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.

In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 BCE, they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a constellation that gave Greek sailors a new way to steer by the stars.

In Thales’ day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole. That’s the point in the sky that is directly above the Earth’s North Pole.

To this day, Kochab and Pherkad are still known as the Guardians of the Pole.

Bottom line: You can find the Big Dipper and Little Dipper in the northern sky at any time of year. On spring evenings, the Big Dipper is high is in the sky. The North Star, Polaris, is located at the end of the Little Dipper’s handle.

The post The Big and Little Dipper: How to find them in the spring first appeared on EarthSky.

from EarthSky https://ift.tt/wVsBEp7

Look for the Big and Little Dipper high in the northern sky on spring evenings. This view is for the Northern Hemisphere. The 2 outer stars in the bowl of the Dipper point to Polaris, the North Star. Polaris marks the end of the handle of the Little Dipper. Chart via EarthSky.

The Big and Little Dipper

The Big Dipper is one of the easiest star patterns to locate in Earth’s sky. It’s visible just about every clear night in the Northern Hemisphere, looking like a big dot-to-dot of a kitchen ladle. As Earth spins, the Big Dipper and its sky neighbor, the Little Dipper, rotate around the North Star, also known as Polaris.

From the northern part of the Northern Hemisphere, the Big and Little Dippers are in the sky continuously. In fact, they are always above your horizon, circling endlessly around Polaris. So given an unobstructed horizon, latitudes north of the 35th parallel (the approximate location of the Mediterranean Sea, Tennessee’s southern border and Kyoto, Japan) can expect to see the Big Dipper at any hour of the night every day of the year.

As for the Little Dipper, it’s circumpolar – always above the horizon – as far south as the Tropic of Cancer (23.5 degrees north latitude).

If you can spot the Big Dipper, then you’re on your way to finding the Little Dipper and the North Star, Polaris, too.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

The Big Dipper rotates around Polaris every night and changes by season

Just remember the old saying: spring up and fall down. So on spring and summer evenings in the Northern Hemisphere, the Big Dipper shines at its highest in the evening sky. Then, on autumn and winter evenings, the Big Dipper sweeps closer to the horizon.

This animation shows the Big Dipper by seasons from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky. Used with permission.

Here’s how to find Polaris and the Little Dipper

Notice that the Big Dipper has two parts, a bowl and a handle. Next, look for the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and they’re known as The Pointers. An imaginary line drawn between them points to Polaris, the North Star. Polaris marks the end of the Little Dipper’s Handle. So, once you have Polaris, you can find the Little Dipper, too … if your sky is dark enough.

So why isn’t the Little Dipper as easy to pick out as the Big Dipper? That’s because the stars between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. As a matter of fact, you’ll need a dark country sky to see all seven of the Little Dipper’s stars.

The Big and Little Dippers are not constellations

Also, the Big Dipper isn’t a constellation. It’s an asterism, or noticeable pattern of stars. The Big Dipper is a clipped version of the constellation Ursa Major the Greater Bear. And the stars of the Big Dipper outline the Bear’s tail and hindquarters.

The Little Dipper is also an asterism. These stars belong to the constellation Ursa Minor the Little Bear.

The Big Dipper will change over time

Astronomers sometimes speak of the fixed stars, but the stars aren’t truly fixed. Stars move in space. Thus the star patterns that we see today as the Big and Little Dippers will, slowly but surely, drift apart over time.

But even 25,000 years from now, the Big Dipper pattern will look nearly the same as it does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.

In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the video below:

Star lore behind the Big and Little Dipper

In the star lore of the Mi’kmaq nation in northern Canada, the Big Dipper is also associated with a bear, but with a twist. The Mi’kmaq see the bowl of the Big Dipper as a Celestial Bear, and the three stars of the handle as hunters chasing the Bear. In the Mi’kmaq tale of the Celestial Bear, in autumn the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autumn landscape

In another version of the story, the Celestial Bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When the Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.

In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 BCE, they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a constellation that gave Greek sailors a new way to steer by the stars.

In Thales’ day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole. That’s the point in the sky that is directly above the Earth’s North Pole.

To this day, Kochab and Pherkad are still known as the Guardians of the Pole.

Bottom line: You can find the Big Dipper and Little Dipper in the northern sky at any time of year. On spring evenings, the Big Dipper is high is in the sky. The North Star, Polaris, is located at the end of the Little Dipper’s handle.

The post The Big and Little Dipper: How to find them in the spring first appeared on EarthSky.

from EarthSky https://ift.tt/wVsBEp7

Partial solar eclipse pics that you’ll love. See them here!

View at EarthSky Community Photos. | Iaroslav Kourzenkov in Halifax, Nova Scotia, Canada, captured the partial solar eclipse on March 29, 2025. Iaroslav wrote: “Witnessed a rare beauty this morning! Caught the stunning partial solar eclipse at sunrise and managed to snap a few photos.” Thank you, Iaroslav! See more great partial solar eclipse pics below.

Partial solar eclipse pics from March 29, 2025

On March 29, 2025, a partial solar eclipse was visible to observers in northeastern North America, Greenland, Iceland, the North Atlantic Ocean, most of Europe and northwestern Russia. Did you miss it? You can still see its majesty in the fabulous photos shared by our EarthSky global community. Did you capture a great pic of your own? Submit it to us!

Photos from our global community

View at EarthSky Community Photos. | Alexander Krivenyshev of WorldTimeZone.com captured these images of the partial solar eclipse on March 29, 2025, from Manhattan. Thank you, Alexander!

View at EarthSky Community Photos. | Kevan Hubbard in Seaton Carew, England, captured this shot of the partial solar eclipse on March 29, 2025. Thanks, Kevan!

View at EarthSky Community Photos. | Juan Manuel Pérez Rayego in Mérida, Spain, captured the partial solar eclipse on March 29, 2025. Thank you, Juan!

More great partial solar eclipse pics

View at EarthSky Community Photos. | Adrian Hayward in Manea, Cambridgeshire, UK, captured this image of the partial solar eclipse on March 29, 2025. Adrian wrote: “One of several taken through the eclipse transition. Cloudy skies prevailed throughout.” Thank you, Adrian!

View at EarthSky Community Photos. | David Chapman in Seaforth, Nova Scotia, Canada, captured the partial solar eclipse on March 29, 2025. David wrote: “I drove to a coastal location northeast of Halifax to avoid the encroaching cloud bank. I observed a point-like green flash as the upper cusp of the crescent around 7:00 ADT. Photo is at peak eclipse and is a bit overexposed.” Thank you, David!

View at EarthSky Community Photos. | Jan Forbrich in Oxford, UK, captured this shot of the partial solar eclipse on March 29, 2025. Thanks, Jan!

2 eclipses in 1 month

View at EarthSky Community Photos. | Andy Heiz caught both the eclipses this month. Andy wrote: “The view of the 2 March eclipses from New Paltz, New York. March 14 and March 29. The clouds covered the moon as the full eclipse was starting and cleared for a picture at sunrise.” Thank you, Andy!

Bottom line: See some beautiful partial solar eclipse pics from March 29, 2025, thanks to our global EarthSky community!

Read more about the March 29 partial solar eclipse

The post Partial solar eclipse pics that you’ll love. See them here! first appeared on EarthSky.

from EarthSky https://ift.tt/9WMIAoj

View at EarthSky Community Photos. | Iaroslav Kourzenkov in Halifax, Nova Scotia, Canada, captured the partial solar eclipse on March 29, 2025. Iaroslav wrote: “Witnessed a rare beauty this morning! Caught the stunning partial solar eclipse at sunrise and managed to snap a few photos.” Thank you, Iaroslav! See more great partial solar eclipse pics below.

Partial solar eclipse pics from March 29, 2025

On March 29, 2025, a partial solar eclipse was visible to observers in northeastern North America, Greenland, Iceland, the North Atlantic Ocean, most of Europe and northwestern Russia. Did you miss it? You can still see its majesty in the fabulous photos shared by our EarthSky global community. Did you capture a great pic of your own? Submit it to us!

Photos from our global community

View at EarthSky Community Photos. | Alexander Krivenyshev of WorldTimeZone.com captured these images of the partial solar eclipse on March 29, 2025, from Manhattan. Thank you, Alexander!

View at EarthSky Community Photos. | Kevan Hubbard in Seaton Carew, England, captured this shot of the partial solar eclipse on March 29, 2025. Thanks, Kevan!

View at EarthSky Community Photos. | Juan Manuel Pérez Rayego in Mérida, Spain, captured the partial solar eclipse on March 29, 2025. Thank you, Juan!

More great partial solar eclipse pics

View at EarthSky Community Photos. | Adrian Hayward in Manea, Cambridgeshire, UK, captured this image of the partial solar eclipse on March 29, 2025. Adrian wrote: “One of several taken through the eclipse transition. Cloudy skies prevailed throughout.” Thank you, Adrian!

View at EarthSky Community Photos. | David Chapman in Seaforth, Nova Scotia, Canada, captured the partial solar eclipse on March 29, 2025. David wrote: “I drove to a coastal location northeast of Halifax to avoid the encroaching cloud bank. I observed a point-like green flash as the upper cusp of the crescent around 7:00 ADT. Photo is at peak eclipse and is a bit overexposed.” Thank you, David!

View at EarthSky Community Photos. | Jan Forbrich in Oxford, UK, captured this shot of the partial solar eclipse on March 29, 2025. Thanks, Jan!

2 eclipses in 1 month

View at EarthSky Community Photos. | Andy Heiz caught both the eclipses this month. Andy wrote: “The view of the 2 March eclipses from New Paltz, New York. March 14 and March 29. The clouds covered the moon as the full eclipse was starting and cleared for a picture at sunrise.” Thank you, Andy!

Bottom line: See some beautiful partial solar eclipse pics from March 29, 2025, thanks to our global EarthSky community!

Read more about the March 29 partial solar eclipse

The post Partial solar eclipse pics that you’ll love. See them here! first appeared on EarthSky.

from EarthSky https://ift.tt/9WMIAoj

How to watch a solar eclipse safely

Raúl Cortés – a co-author of EarthSky’s daily sun post – is the one on the top right in this photo. He lives in Mexico. But he and his family traveled to Corpus Christi, Texas, to place themselves in the path of the annular eclipse on October 14, 2023. Thank you, Raúl! Read tips below on how to safely watch a solar eclipse.

You learned long ago never to look directly at the sun. Gazing sunward without eye protection can permanently damage your eyes. But there are a variety of ways you can safely view the March 29, 2025, partial solar eclipse.

Sky viewing: Do NOT use these techniques

First, let’s cover what you shouldn’t do to look at the sun. Whatever you do, never look at the sun directly without a safe filter in place to protect your eyes.

Besides your unprotected eyeballs, here are some other things you should not use: Do NOT use sunglasses, polaroid filters, smoked glass, exposed color film, X-ray film, or photographic neutral density filters.

Fred Espenak created this self-portrait during a 2006 total solar eclipse. He’s using a small telescope equipped with a solar filter for observing the sun safely. Thank you, Fred! Used with permission. Read the ways to watch a solar eclipse – and the sun – safely, below.

DO use these techniques for observing the sun safely

Safe commercial solar filters for a telescope. If you have a ‘scope, you’ll need a safe solar filter on the sky end of it in order to search for sunspots or watch a solar eclipse safely. Do not use a filter on the eyepiece end of your telescope. There’s too much to say about solar filters to include in this article, so we refer you to Fred Espenak’s article on safe solar filters. If you don’t have a ‘scope, you still have plenty of options, such as …

A home-rigged, indirect viewing method. We recommend this article by the masters of do-it-yourself science at the Exploratorium in San Francisco.

Creating a pinhole camera is another great option. It lets your family and friends get a good view of the sun, too. You can make a DIY easy pinhole projector. With it, you can shine the sun’s image onto a flat surface and impress your friends and neighbors while giving everyone (including yourself) a cool experience.

Use handy things around the house. You can use a colander, a slotted spoon or even criss-cross your fingers and let the sun shine through them to see dozens of little eclipsed suns on the ground.

Use a colander as an easy pinhole projector to safely view a solar eclipse. Image via Marcy Curran.

Check out the ground below trees

The little pinholes in leaves on trees are a wonderful pinhole projector.

This young astronomer in Austin, Texas, is using solar binoculars, especially designed for watching eclipses and tracking sunspots. See the crescent suns at his feet? Those are projected images of the eclipsed sun. Image via EarthSky.

But wait, there’s more …

A commercial pinhole projector. There are several versions of this handy and unique device to safely project an image of the sun. The Sunspotter projects an enlarged image of the sun onto a piece of paper, and even shows all but the smallest sunspots. It’s easy to use, plus multiple people can safely watch the eclipse (or see sunspots) at the same time. Of course, for solar eclipses the advancing – and eventual retreating – of the moon’s shadow is easy to see and even photograph.

Commercial sun projection devices are available as well, such as this Sunspotter. They use lenses to project the sun on a piece of paper to safely watch solar eclipses and to view sunspots. Image via Marcy Curran.

Commercial solar eclipse glasses. You might find these online or at a local nature center or museum. Solar eclipse glasses – or eclipse viewers – are super easy to use, and they’re sort of cool-looking.

Certified eclipse glasses are a safe alternative for viewing.

Watch a solar eclipse with others

Local viewing at an astronomy club, park or nature center. We highly recommend this route for any kind of eclipse, any daytime solar viewing, or any nighttime astronomical event. If you watch among other amateur astronomers and casual sky gazers, you’ll have fun, learn about astronomy and get a great view of the objects and events going on in the sky.

The NASA Night Sky Network has a list of local astronomy clubs in the U.S. Here’s a search page from Go-astronomy.com which includes worldwide clubs. And here are astronomy clubs and societies affiliated with the Astronomical League, one of the most established confederations of amateur astronomers in the U.S.

Bottom line: Some tips for observing the sun safely during a solar eclipse here.

Read about the March 29, 2025, partial solar eclipse

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

The post How to watch a solar eclipse safely first appeared on EarthSky.

from EarthSky https://ift.tt/1h9PmZ5

Raúl Cortés – a co-author of EarthSky’s daily sun post – is the one on the top right in this photo. He lives in Mexico. But he and his family traveled to Corpus Christi, Texas, to place themselves in the path of the annular eclipse on October 14, 2023. Thank you, Raúl! Read tips below on how to safely watch a solar eclipse.

You learned long ago never to look directly at the sun. Gazing sunward without eye protection can permanently damage your eyes. But there are a variety of ways you can safely view the March 29, 2025, partial solar eclipse.

Sky viewing: Do NOT use these techniques

First, let’s cover what you shouldn’t do to look at the sun. Whatever you do, never look at the sun directly without a safe filter in place to protect your eyes.

Besides your unprotected eyeballs, here are some other things you should not use: Do NOT use sunglasses, polaroid filters, smoked glass, exposed color film, X-ray film, or photographic neutral density filters.

Fred Espenak created this self-portrait during a 2006 total solar eclipse. He’s using a small telescope equipped with a solar filter for observing the sun safely. Thank you, Fred! Used with permission. Read the ways to watch a solar eclipse – and the sun – safely, below.

DO use these techniques for observing the sun safely

Safe commercial solar filters for a telescope. If you have a ‘scope, you’ll need a safe solar filter on the sky end of it in order to search for sunspots or watch a solar eclipse safely. Do not use a filter on the eyepiece end of your telescope. There’s too much to say about solar filters to include in this article, so we refer you to Fred Espenak’s article on safe solar filters. If you don’t have a ‘scope, you still have plenty of options, such as …

A home-rigged, indirect viewing method. We recommend this article by the masters of do-it-yourself science at the Exploratorium in San Francisco.

Creating a pinhole camera is another great option. It lets your family and friends get a good view of the sun, too. You can make a DIY easy pinhole projector. With it, you can shine the sun’s image onto a flat surface and impress your friends and neighbors while giving everyone (including yourself) a cool experience.

Use handy things around the house. You can use a colander, a slotted spoon or even criss-cross your fingers and let the sun shine through them to see dozens of little eclipsed suns on the ground.

Use a colander as an easy pinhole projector to safely view a solar eclipse. Image via Marcy Curran.

Check out the ground below trees

The little pinholes in leaves on trees are a wonderful pinhole projector.

This young astronomer in Austin, Texas, is using solar binoculars, especially designed for watching eclipses and tracking sunspots. See the crescent suns at his feet? Those are projected images of the eclipsed sun. Image via EarthSky.

But wait, there’s more …

A commercial pinhole projector. There are several versions of this handy and unique device to safely project an image of the sun. The Sunspotter projects an enlarged image of the sun onto a piece of paper, and even shows all but the smallest sunspots. It’s easy to use, plus multiple people can safely watch the eclipse (or see sunspots) at the same time. Of course, for solar eclipses the advancing – and eventual retreating – of the moon’s shadow is easy to see and even photograph.

Commercial sun projection devices are available as well, such as this Sunspotter. They use lenses to project the sun on a piece of paper to safely watch solar eclipses and to view sunspots. Image via Marcy Curran.

Commercial solar eclipse glasses. You might find these online or at a local nature center or museum. Solar eclipse glasses – or eclipse viewers – are super easy to use, and they’re sort of cool-looking.

Certified eclipse glasses are a safe alternative for viewing.

Watch a solar eclipse with others

Local viewing at an astronomy club, park or nature center. We highly recommend this route for any kind of eclipse, any daytime solar viewing, or any nighttime astronomical event. If you watch among other amateur astronomers and casual sky gazers, you’ll have fun, learn about astronomy and get a great view of the objects and events going on in the sky.

The NASA Night Sky Network has a list of local astronomy clubs in the U.S. Here’s a search page from Go-astronomy.com which includes worldwide clubs. And here are astronomy clubs and societies affiliated with the Astronomical League, one of the most established confederations of amateur astronomers in the U.S.

Bottom line: Some tips for observing the sun safely during a solar eclipse here.

Read about the March 29, 2025, partial solar eclipse

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

The post How to watch a solar eclipse safely first appeared on EarthSky.

from EarthSky https://ift.tt/1h9PmZ5

Curiosity Found New Carbon Molecules On Mars. What Does It Mean For Alien Life?

Curiosity Found New Carbon Molecules On Mars. What Does It Mean For Alien Life?

Nasa’s Curiosity Mars rover has detected the largest organic (carbon-containing) molecules ever found on the red planet. The discovery is one of the most significant findings in the search for evidence of past life on Mars. This is because, on Earth at least, relatively complex, long-chain carbon molecules are involved in biology. These molecules could actually be fragments of fatty acids, which are found in, for example, the membranes surrounding biological cells.

 

Scientists think that, if life ever emerged on Mars, it was probably microbial in nature. Because microbes are so small, it’s difficult to be definitive about any potential evidence for life found on Mars. Such evidence needs more powerful scientific instruments that are too large to be put on a rover.

Curiosity rover near the site of Mont Mercou on Mars. Source: NASA/JPL-Caltech/MSSS

 

The organic molecules found by Curiosity consist of carbon atoms linked in long chains, with other elements bonded to them, like hydrogen and oxygen. They come from a 3.7-billion-year-old rock dubbed Cumberland, encountered by the rover at a presumed dried-up lakebed in Mars’s Gale Crater. Scientists used the Sample Analysis at Mars (Sam) instrument on the Nasa rover to make their discovery.

 

Scientists were actually looking for evidence of amino acids, which are the building blocks of proteins and therefore key components of life as we know it. But this unexpected finding is almost as exciting. The research is published in Proceedings of the National Academies of Science.

 

Among the molecules were decane, which has 10 carbon atoms and 22 hydrogen atoms, and dodecane, with 12 carbons and 26 hydrogen atoms. These are known as alkanes, which fall under the umbrella of the chemical compounds known as hydrocarbons.

 

It’s an exciting time in the search for life on Mars. In March this year, scientists presented evidence of features in a different rock sampled elsewhere on Mars by the Perseverance rover. These features, dubbed “leopard spots” and “poppy seeds”, could have been produced by the action of microbial life in the distant past, or not. The findings were presented at a US conference and have not yet been published in a peer reviewed journal.

 

The Mars Sample Return mission, a collaboration between Nasa and the European Space Agency, offers hope that samples of rock collected and stored by Perseverance could be brought to Earth for study in laboratories. The powerful instruments available in terrestrial labs could finally confirm whether or not there is clear evidence for past life on Mars. However, in 2023, an independent review board criticized increases in Mars Sample Return’s budget. This prompted the agencies to rethink how the mission could be carried out. They are currently studying two revised options.

 

Signs of life?

 

Cumberland was found in a region of Gale Crater called Yellowknife Bay. This area contains rock formations that look suspiciously like those formed when sediment builds up at the bottom of a lake. One of Curiosity’s scientific goals is to examine the prospect that past conditions on Mars would have been suitable for the development of life, so an ancient lakebed is the perfect place to look for them.

The Martian rock known as Cumberland, which was sampled in the study. Credit: NASA/JPL-Caltech/MSSS

 

The researchers think that the alkane molecules may once have been components of more complex fatty acid molecules. On Earth, fatty acids are components of fats and oils. They are produced through biological activity in processes that help form cell membranes, for example. The suggested presence of fatty acids in this rock sample has been around for several years, but the new paper details the full evidence.

Fatty acids are long, linear hydrocarbon molecules with a carboxyl group (COOH) at one end and a methyl group (CH3) at the other, forming a chain of carbon and hydrogen atoms.

A fat molecule consists of two main components: glycerol and fatty acids. Glycerol is an alcohol molecule with three carbon atoms, five hydrogens, and three hydroxyl (chemically bonded oxygen and hydrogen, OH) groups. Fatty acids may have 4-36 carbon atoms; however, most of them have 12-18. The longest carbon chains found in Cumberland are 12 atoms long.

Mars Sample Return will deliver Mars rocks to Earth for study. This artist’s impression shows the ascent vehicle leaving Mars with rock samples. Nasa/JPL-Caltech

 

Organic molecules preserved in ancient Martian rocks provide a critical record of the past habitability of Mars and could be chemical biosignatures (signs that life was once there).

 

The sample from Cumberland has been analyzed by the Sam instrument many times, using different experimental techniques, and has shown evidence of clay minerals, as well as the first (smaller and simpler) organic molecules found on Mars, back in 2015. These included several classes of chlorinated and sulphur-containing organic compounds in Gale crater sedimentary rocks, with chemical structures of up to six carbon atoms. The new discovery doubles the number of carbon atoms found in a single molecule on Mars.

 

The alkane molecules are significant in the search for biosignatures on Mars, but how they actually formed remains unclear. They could also be derived through geological or other chemical mechanisms that do not involve fatty acids or life. These are known as abiotic sources. However, the fact that they exist intact today in samples that have been exposed to a harsh environment for many millions of years gives astrobiologists (scientists who study the possibility of life beyond Earth) hope that evidence of ancient life might still be detectable today.

 

It is possible the sample contains even longer chain organic molecules. It may also contain more complex molecules that are indicative of life, rather than geological processes. Unfortunately, Sam is not capable of detecting those, so the next step is to deliver Martian rock and soil to more capable laboratories on the Earth. Mars Sample Return would do this with the samples already gathered by the Perseverance Mars rover. All that’s needed now is the budget.

 

By Derek Ward-Thompson, Professor of Astrophysics, University of Central Lancashire and Megan Argo, Senior Lecturer in Astronomy, University of Central Lancashire. This article is republished from The Conversation under a Creative Commons license. Read the original article.

sb admin Fri, 03/28/2025 - 13:12

Categories

Life Sciences

from ScienceBlogs - Where the world discusses science https://ift.tt/2bskvCc

Curiosity Found New Carbon Molecules On Mars. What Does It Mean For Alien Life?

Nasa’s Curiosity Mars rover has detected the largest organic (carbon-containing) molecules ever found on the red planet. The discovery is one of the most significant findings in the search for evidence of past life on Mars. This is because, on Earth at least, relatively complex, long-chain carbon molecules are involved in biology. These molecules could actually be fragments of fatty acids, which are found in, for example, the membranes surrounding biological cells.

 

Scientists think that, if life ever emerged on Mars, it was probably microbial in nature. Because microbes are so small, it’s difficult to be definitive about any potential evidence for life found on Mars. Such evidence needs more powerful scientific instruments that are too large to be put on a rover.

Curiosity rover near the site of Mont Mercou on Mars. Source: NASA/JPL-Caltech/MSSS

 

The organic molecules found by Curiosity consist of carbon atoms linked in long chains, with other elements bonded to them, like hydrogen and oxygen. They come from a 3.7-billion-year-old rock dubbed Cumberland, encountered by the rover at a presumed dried-up lakebed in Mars’s Gale Crater. Scientists used the Sample Analysis at Mars (Sam) instrument on the Nasa rover to make their discovery.

 

Scientists were actually looking for evidence of amino acids, which are the building blocks of proteins and therefore key components of life as we know it. But this unexpected finding is almost as exciting. The research is published in Proceedings of the National Academies of Science.

 

Among the molecules were decane, which has 10 carbon atoms and 22 hydrogen atoms, and dodecane, with 12 carbons and 26 hydrogen atoms. These are known as alkanes, which fall under the umbrella of the chemical compounds known as hydrocarbons.

 

It’s an exciting time in the search for life on Mars. In March this year, scientists presented evidence of features in a different rock sampled elsewhere on Mars by the Perseverance rover. These features, dubbed “leopard spots” and “poppy seeds”, could have been produced by the action of microbial life in the distant past, or not. The findings were presented at a US conference and have not yet been published in a peer reviewed journal.

 

The Mars Sample Return mission, a collaboration between Nasa and the European Space Agency, offers hope that samples of rock collected and stored by Perseverance could be brought to Earth for study in laboratories. The powerful instruments available in terrestrial labs could finally confirm whether or not there is clear evidence for past life on Mars. However, in 2023, an independent review board criticized increases in Mars Sample Return’s budget. This prompted the agencies to rethink how the mission could be carried out. They are currently studying two revised options.

 

Signs of life?

 

Cumberland was found in a region of Gale Crater called Yellowknife Bay. This area contains rock formations that look suspiciously like those formed when sediment builds up at the bottom of a lake. One of Curiosity’s scientific goals is to examine the prospect that past conditions on Mars would have been suitable for the development of life, so an ancient lakebed is the perfect place to look for them.

The Martian rock known as Cumberland, which was sampled in the study. Credit: NASA/JPL-Caltech/MSSS

 

The researchers think that the alkane molecules may once have been components of more complex fatty acid molecules. On Earth, fatty acids are components of fats and oils. They are produced through biological activity in processes that help form cell membranes, for example. The suggested presence of fatty acids in this rock sample has been around for several years, but the new paper details the full evidence.

Fatty acids are long, linear hydrocarbon molecules with a carboxyl group (COOH) at one end and a methyl group (CH3) at the other, forming a chain of carbon and hydrogen atoms.

A fat molecule consists of two main components: glycerol and fatty acids. Glycerol is an alcohol molecule with three carbon atoms, five hydrogens, and three hydroxyl (chemically bonded oxygen and hydrogen, OH) groups. Fatty acids may have 4-36 carbon atoms; however, most of them have 12-18. The longest carbon chains found in Cumberland are 12 atoms long.

Mars Sample Return will deliver Mars rocks to Earth for study. This artist’s impression shows the ascent vehicle leaving Mars with rock samples. Nasa/JPL-Caltech

 

Organic molecules preserved in ancient Martian rocks provide a critical record of the past habitability of Mars and could be chemical biosignatures (signs that life was once there).

 

The sample from Cumberland has been analyzed by the Sam instrument many times, using different experimental techniques, and has shown evidence of clay minerals, as well as the first (smaller and simpler) organic molecules found on Mars, back in 2015. These included several classes of chlorinated and sulphur-containing organic compounds in Gale crater sedimentary rocks, with chemical structures of up to six carbon atoms. The new discovery doubles the number of carbon atoms found in a single molecule on Mars.

 

The alkane molecules are significant in the search for biosignatures on Mars, but how they actually formed remains unclear. They could also be derived through geological or other chemical mechanisms that do not involve fatty acids or life. These are known as abiotic sources. However, the fact that they exist intact today in samples that have been exposed to a harsh environment for many millions of years gives astrobiologists (scientists who study the possibility of life beyond Earth) hope that evidence of ancient life might still be detectable today.

 

It is possible the sample contains even longer chain organic molecules. It may also contain more complex molecules that are indicative of life, rather than geological processes. Unfortunately, Sam is not capable of detecting those, so the next step is to deliver Martian rock and soil to more capable laboratories on the Earth. Mars Sample Return would do this with the samples already gathered by the Perseverance Mars rover. All that’s needed now is the budget.

 

By Derek Ward-Thompson, Professor of Astrophysics, University of Central Lancashire and Megan Argo, Senior Lecturer in Astronomy, University of Central Lancashire. This article is republished from The Conversation under a Creative Commons license. Read the original article.

sb admin Fri, 03/28/2025 - 13:12

Categories

Life Sciences

from ScienceBlogs - Where the world discusses science https://ift.tt/2bskvCc