Above-average hurricane forecast for the Atlantic in 2025

Hurricane Beryl nearing Category 5 intensity in early July 2024. Get the 2025 hurricane forecast for the Atlantic basin below. Image via Atlantic Oceanographic and Meteorological Laboratory/ NOAA.

Hurricane forecast for the Atlantic in 2025

Colorado State University has been predicting tropical activity for the Atlantic hurricane season for 42 years. On Thursday, April 3, 2025, they released their 42nd pre-season hurricane forecast, and it calls for above average-average activity in the tropical Atlantic for the 2025 hurricane season. CSU is forecasting:

17 named storms
9 hurricanes
4 major hurricanes

This is above the 30-year-average (1991-2020) of:
14 named storms
7 hurricanes
3 major hurricanes

The 2024 Atlantic hurricane season saw 18 named storms, 11 hurricanes and five major hurricanes (Category 3 or higher).

Reasoning behind the hurricane forecast

Researchers at Colorado State University base their forecast on 40 years of past data as well as what they call analogs. Analogs are a forecast solution that predicts future weather patterns by identifying past weather situations that closely resemble current conditions. In addition to these analogs, CSU also used up to 40 years of model data from four different meteorological agencies from all over the world. The researchers say all these data are pointing toward a more-active-than-normal hurricane season. There are a few specific areas that CSU focused on for their forecast: ENSO phases and water temperature.

El Niño Southern Oscillation

El Niño Southern Oscillation, also called ENSO, is a global climate pattern that influences weather around the world, including tropical weather. The current ENSO phase is the cool phase, La Niña, during which the waters in the tropical Pacific Ocean are cooler than average.

La Niña can influence tropical development in the Atlantic, however. La Niña doesn’t allow for the development of strong wind shear (a change in wind direction and/or speed with height) over the Atlantic. Wind shear tears apart or weakens hurricanes, so less wind shear during La Niña won’t as easily hinder the development of tropical storms and hurricanes.

The typical influence on tropical weather when La Niña is in place. Image via NOAA.

But La Niña should not continue into the summer. Forecasters predict a switch to ENSO neutral (not fully La Niña or El Niño) during the month of April. And they predict a 62% chance of neutral conditions lasting through August. They do not expect a complete switch to El Niño.

To put it simply, you can think of El Niño as the opposite of La Niña, as it is the warm phase of ENSO. El Niño would create more wind shear over the tropical Atlantic and make it more difficult for tropical systems to develop. But remember: the forecast is for a switch to a neutral phase, not fully El Niño. Due to uncertainty as to what ENSO phase will truly persist through hurricane season, including the possibility of a lingering La Niña, CSU researchers believe this will still have an impact on tropical cyclone development.

Water temperatures

Tropical cyclones, by definition, form over and get their fuel from warm ocean water of at least 80 degrees Fahrenheit (27 Celsius). Water temperatures over the tropical Atlantic are already warmer than average, with the exception of in the far eastern Atlantic where water temperatures are slightly cooler than average. Where water temperatures are currently cooler than average, strong trades have mixed more of the water, making it cooler.

However, within the coming weeks, those trades winds are expected to be weaker, allowing the area with cooler water to gradually warm up and keep the rest of the waters across the Atlantic warmer than average.

Warmer-than-average water temperatures paired with La Niña or even neutral conditions have the potential to create an environment where tropical systems could develop without much inhibition.

Retired names and 2025 Atlantic Basin names

The 2024 Atlantic hurricane season was an active one as well. It had 18 named storms, 11 hurricanes and five major hurricanes. Three of the storms caused so much devastation that their names will never be used again. The names Beryl, Helene and Milton are retired for the Atlantic Basin and will be replaced by Brianna, Holly and Miguel. (Tropical cyclone names are reused every six years, so the next time the 2024 list of names will come up again will be 2030).

The names for the 2025 season are:

Andrea          Barry            Chantal
Dexter           Erin               Fernand
Gabrielle      Humberto   Imelda
Jerry              Karen           Lorenzo
Melissa         Nestor           Olga
Pablo            Rebekah        Sebastien
Tanya            Van                Wendy

Read more about 2025’s hurricane names here.

Hurricane preparedness

Hurricane season in the Atlantic basin begins June 1 and runs through November 30 every year. But the time to be prepared for impacts from a tropical cyclone is before hurricane season begins. You should know your risks from a tropical storm or hurricane: is your biggest threat water or wind? Are you in an evacuation zone, and where should you go when called to evacuate? You should also prepare a hurricane kit full of medicine, fresh water, non-perishable food (and a can opener!) for every person and every pet in your household, plus a radio, chargers and cash. Find more hurricane preparedness tips at NOAA.

A list of tasks to prepare for hurricane season. Via National Weather Service/ NOAA.

Bottom Line: Researchers with Colorado State University are calling for another more-active-than-normal hurricane season with 17 total named storms, nine hurricanes and four major hurricanes.

Read the in-depth report

Stay up to date with all tropical forecasts at NOAA’s National Hurricane Center

Via NOAA

The post Above-average hurricane forecast for the Atlantic in 2025 first appeared on EarthSky.

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

Hurricane Beryl nearing Category 5 intensity in early July 2024. Get the 2025 hurricane forecast for the Atlantic basin below. Image via Atlantic Oceanographic and Meteorological Laboratory/ NOAA.

Hurricane forecast for the Atlantic in 2025

Colorado State University has been predicting tropical activity for the Atlantic hurricane season for 42 years. On Thursday, April 3, 2025, they released their 42nd pre-season hurricane forecast, and it calls for above average-average activity in the tropical Atlantic for the 2025 hurricane season. CSU is forecasting:

17 named storms
9 hurricanes
4 major hurricanes

This is above the 30-year-average (1991-2020) of:
14 named storms
7 hurricanes
3 major hurricanes

The 2024 Atlantic hurricane season saw 18 named storms, 11 hurricanes and five major hurricanes (Category 3 or higher).

Reasoning behind the hurricane forecast

Researchers at Colorado State University base their forecast on 40 years of past data as well as what they call analogs. Analogs are a forecast solution that predicts future weather patterns by identifying past weather situations that closely resemble current conditions. In addition to these analogs, CSU also used up to 40 years of model data from four different meteorological agencies from all over the world. The researchers say all these data are pointing toward a more-active-than-normal hurricane season. There are a few specific areas that CSU focused on for their forecast: ENSO phases and water temperature.

El Niño Southern Oscillation

El Niño Southern Oscillation, also called ENSO, is a global climate pattern that influences weather around the world, including tropical weather. The current ENSO phase is the cool phase, La Niña, during which the waters in the tropical Pacific Ocean are cooler than average.

La Niña can influence tropical development in the Atlantic, however. La Niña doesn’t allow for the development of strong wind shear (a change in wind direction and/or speed with height) over the Atlantic. Wind shear tears apart or weakens hurricanes, so less wind shear during La Niña won’t as easily hinder the development of tropical storms and hurricanes.

The typical influence on tropical weather when La Niña is in place. Image via NOAA.

But La Niña should not continue into the summer. Forecasters predict a switch to ENSO neutral (not fully La Niña or El Niño) during the month of April. And they predict a 62% chance of neutral conditions lasting through August. They do not expect a complete switch to El Niño.

To put it simply, you can think of El Niño as the opposite of La Niña, as it is the warm phase of ENSO. El Niño would create more wind shear over the tropical Atlantic and make it more difficult for tropical systems to develop. But remember: the forecast is for a switch to a neutral phase, not fully El Niño. Due to uncertainty as to what ENSO phase will truly persist through hurricane season, including the possibility of a lingering La Niña, CSU researchers believe this will still have an impact on tropical cyclone development.

Water temperatures

Tropical cyclones, by definition, form over and get their fuel from warm ocean water of at least 80 degrees Fahrenheit (27 Celsius). Water temperatures over the tropical Atlantic are already warmer than average, with the exception of in the far eastern Atlantic where water temperatures are slightly cooler than average. Where water temperatures are currently cooler than average, strong trades have mixed more of the water, making it cooler.

However, within the coming weeks, those trades winds are expected to be weaker, allowing the area with cooler water to gradually warm up and keep the rest of the waters across the Atlantic warmer than average.

Warmer-than-average water temperatures paired with La Niña or even neutral conditions have the potential to create an environment where tropical systems could develop without much inhibition.

Retired names and 2025 Atlantic Basin names

The 2024 Atlantic hurricane season was an active one as well. It had 18 named storms, 11 hurricanes and five major hurricanes. Three of the storms caused so much devastation that their names will never be used again. The names Beryl, Helene and Milton are retired for the Atlantic Basin and will be replaced by Brianna, Holly and Miguel. (Tropical cyclone names are reused every six years, so the next time the 2024 list of names will come up again will be 2030).

The names for the 2025 season are:

Andrea          Barry            Chantal
Dexter           Erin               Fernand
Gabrielle      Humberto   Imelda
Jerry              Karen           Lorenzo
Melissa         Nestor           Olga
Pablo            Rebekah        Sebastien
Tanya            Van                Wendy

Read more about 2025’s hurricane names here.

Hurricane preparedness

Hurricane season in the Atlantic basin begins June 1 and runs through November 30 every year. But the time to be prepared for impacts from a tropical cyclone is before hurricane season begins. You should know your risks from a tropical storm or hurricane: is your biggest threat water or wind? Are you in an evacuation zone, and where should you go when called to evacuate? You should also prepare a hurricane kit full of medicine, fresh water, non-perishable food (and a can opener!) for every person and every pet in your household, plus a radio, chargers and cash. Find more hurricane preparedness tips at NOAA.

A list of tasks to prepare for hurricane season. Via National Weather Service/ NOAA.

Bottom Line: Researchers with Colorado State University are calling for another more-active-than-normal hurricane season with 17 total named storms, nine hurricanes and four major hurricanes.

Read the in-depth report

Stay up to date with all tropical forecasts at NOAA’s National Hurricane Center

Via NOAA

The post Above-average hurricane forecast for the Atlantic in 2025 first appeared on EarthSky.

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

See the Atlantic hurricanes name list for 2025

Here’s the list of names for tropical cyclones and hurricanes in 2025 for the Atlantic basin.

Names for Atlantic hurricanes and tropical cyclones

The 2025 Atlantic hurricane season officially starts June 1 and extends through November 30. NOAA’s Climate Prediction Center will release their hurricane season outlook for this year in late May. Meanwhile, Colorado State University (CSU) also puts out a hurricane outlook, which it issued on April 3. But what are the names for the 2025 Atlantic tropical cyclones and hurricanes?

See the complete list of 2025 tropical cyclone and hurricane names above. If any of these storms become truly destructive in 2025, the World Meteorological Organization, which is in charge of the list, retires and replaces the name. For example, in 2024, the World Meteorological Organization retired the names Beryl, Helene and Milton. Helene, in particular, became the deadliest storm in the U.S. since Katrina in 2005.

If you live near the Atlantic basin, you should keep up-to-date with forecasts from the National Hurricane Center.

Learn more about how to prepare for hurricane season.

2025 EarthSky lunar calendar is available. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Where do hurricane names come from?

Meteorologists long ago learned that naming tropical storms and hurricanes helps people remember the storms, communicate about them more effectively, and consequently stay safer if and when a particular storm strikes a coast.

These experts assign names to tropical storms according to an approved list before the start of each hurricane season. The U.S. National Hurricane Center started this practice in the early 1950s. Now, the World Meteorological Organization (WMO) generates and maintains the list of hurricane names.

Here are the hurricane names for 2025

Atlantic hurricane names (season runs from June 1 to November 30) are: Andrea, Barry, Chantal, Dexter, Erin, Fernand, Gabrielle, Humberto, Imelda, Jerry, Karen, Lorenzo, Melissa, Nestor, Olga, Pablo, Rebekah, Sebastien, Tanya, Van and Wendy.

Eastern North Pacific hurricane names (season runs from May 15 to November 30) are: Alvin, Barbara, Cosme, Dalila, Erick, Flossie, Gil, Henriette, Ivo, Juliette, Kiko, Lorena, Mario, Narda, Octave, Priscilla, Raymond, Sonia, Tico, Velma, Wallis, Xina, York and Zelda.

If you’re interested, you can view those names, and names for upcoming years, at the U.S. National Hurricane Center.

In 2022, Hurricane Ian devastated Florida’s Gulf Coast. It also brought flooding to central Florida, ripped roofs off on the Atlantic Coast and then menaced South Carolina. The name Ian will never again be used for a tropical cyclone or hurricane. Image via NOAA/ GOES.

How and why did hurricanes first begin receiving names?

While people have been naming major storms for hundreds of years, most hurricanes originally had a designation using a system of latitude-longitude numbers. This was useful to meteorologists trying to track these storms. Unfortunately, this system confused people living on coasts seeking hurricane information.

In the early 1950s, the U.S. National Hurricane Center first developed a formal practice for storm naming for the Atlantic Ocean. At that time, storms got their names according to a phonetic alphabet (e.g., Able, Baker, Charlie) and the names used were the same for each hurricane season. In other words, the first hurricane of a season was always named “Able,” the second “Baker,” and so on.

In 1953, to avoid the repetitive use of names, the National Weather Service revised the system to give storms female names. By doing this, the National Weather Service was mimicking the habit of naval meteorologists, who named the storms after women, much as ships at sea traditionally had female names.

In 1978–1979, they revised the system again to include both female and male hurricane names.

See the complete history of naming hurricanes, including retired names, from NOAA.

When does a storm receive a name?

Tropical storms get a name when they display a rotating circulation pattern and wind speeds reach 39 miles per hour (63 kilometers per hour). A tropical storm develops into a hurricane when wind speeds go above 74 mph (119 km/h).

Experts have developed lists of hurricane names for many of the major ocean basins around the world. Today, there are six lists of hurricane names in use for Atlantic Ocean and Eastern North Pacific storms. These lists rotate, one each year. So that means the list of this year’s hurricane names for each basin will come up again six years from now.

However, there’s an exception to this practice. The World Meteorological Organization retires the names of extremely damaging hurricanes for legal, cultural sensitivity and historical reasons. For example, they retired the name Katrina in 2005 following the devastating impact that Hurricane Katrina had on New Orleans. In 2022, the World Meteorological Organization Hurricane Committee retired the names Fiona and Ian.

Hurricane Katrina on August 28, 2005. Image via NASA.

Bottom line: Get the list of names for the 2025 season for Atlantic tropical cyclones and hurricanes. Read more about how the naming system came to be.

Read more: What is a hurricane storm surge?

The post See the Atlantic hurricanes name list for 2025 first appeared on EarthSky.

from EarthSky https://ift.tt/XLVrvuc

Here’s the list of names for tropical cyclones and hurricanes in 2025 for the Atlantic basin.

Names for Atlantic hurricanes and tropical cyclones

The 2025 Atlantic hurricane season officially starts June 1 and extends through November 30. NOAA’s Climate Prediction Center will release their hurricane season outlook for this year in late May. Meanwhile, Colorado State University (CSU) also puts out a hurricane outlook, which it issued on April 3. But what are the names for the 2025 Atlantic tropical cyclones and hurricanes?

See the complete list of 2025 tropical cyclone and hurricane names above. If any of these storms become truly destructive in 2025, the World Meteorological Organization, which is in charge of the list, retires and replaces the name. For example, in 2024, the World Meteorological Organization retired the names Beryl, Helene and Milton. Helene, in particular, became the deadliest storm in the U.S. since Katrina in 2005.

If you live near the Atlantic basin, you should keep up-to-date with forecasts from the National Hurricane Center.

Learn more about how to prepare for hurricane season.

2025 EarthSky lunar calendar is available. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Where do hurricane names come from?

Meteorologists long ago learned that naming tropical storms and hurricanes helps people remember the storms, communicate about them more effectively, and consequently stay safer if and when a particular storm strikes a coast.

These experts assign names to tropical storms according to an approved list before the start of each hurricane season. The U.S. National Hurricane Center started this practice in the early 1950s. Now, the World Meteorological Organization (WMO) generates and maintains the list of hurricane names.

Here are the hurricane names for 2025

Atlantic hurricane names (season runs from June 1 to November 30) are: Andrea, Barry, Chantal, Dexter, Erin, Fernand, Gabrielle, Humberto, Imelda, Jerry, Karen, Lorenzo, Melissa, Nestor, Olga, Pablo, Rebekah, Sebastien, Tanya, Van and Wendy.

Eastern North Pacific hurricane names (season runs from May 15 to November 30) are: Alvin, Barbara, Cosme, Dalila, Erick, Flossie, Gil, Henriette, Ivo, Juliette, Kiko, Lorena, Mario, Narda, Octave, Priscilla, Raymond, Sonia, Tico, Velma, Wallis, Xina, York and Zelda.

If you’re interested, you can view those names, and names for upcoming years, at the U.S. National Hurricane Center.

In 2022, Hurricane Ian devastated Florida’s Gulf Coast. It also brought flooding to central Florida, ripped roofs off on the Atlantic Coast and then menaced South Carolina. The name Ian will never again be used for a tropical cyclone or hurricane. Image via NOAA/ GOES.

How and why did hurricanes first begin receiving names?

While people have been naming major storms for hundreds of years, most hurricanes originally had a designation using a system of latitude-longitude numbers. This was useful to meteorologists trying to track these storms. Unfortunately, this system confused people living on coasts seeking hurricane information.

In the early 1950s, the U.S. National Hurricane Center first developed a formal practice for storm naming for the Atlantic Ocean. At that time, storms got their names according to a phonetic alphabet (e.g., Able, Baker, Charlie) and the names used were the same for each hurricane season. In other words, the first hurricane of a season was always named “Able,” the second “Baker,” and so on.

In 1953, to avoid the repetitive use of names, the National Weather Service revised the system to give storms female names. By doing this, the National Weather Service was mimicking the habit of naval meteorologists, who named the storms after women, much as ships at sea traditionally had female names.

In 1978–1979, they revised the system again to include both female and male hurricane names.

See the complete history of naming hurricanes, including retired names, from NOAA.

When does a storm receive a name?

Tropical storms get a name when they display a rotating circulation pattern and wind speeds reach 39 miles per hour (63 kilometers per hour). A tropical storm develops into a hurricane when wind speeds go above 74 mph (119 km/h).

Experts have developed lists of hurricane names for many of the major ocean basins around the world. Today, there are six lists of hurricane names in use for Atlantic Ocean and Eastern North Pacific storms. These lists rotate, one each year. So that means the list of this year’s hurricane names for each basin will come up again six years from now.

However, there’s an exception to this practice. The World Meteorological Organization retires the names of extremely damaging hurricanes for legal, cultural sensitivity and historical reasons. For example, they retired the name Katrina in 2005 following the devastating impact that Hurricane Katrina had on New Orleans. In 2022, the World Meteorological Organization Hurricane Committee retired the names Fiona and Ian.

Hurricane Katrina on August 28, 2005. Image via NASA.

Bottom line: Get the list of names for the 2025 season for Atlantic tropical cyclones and hurricanes. Read more about how the naming system came to be.

Read more: What is a hurricane storm surge?

The post See the Atlantic hurricanes name list for 2025 first appeared on EarthSky.

from EarthSky https://ift.tt/XLVrvuc

Surprising galaxy shines through fog of the early universe

This image shows the incredibly distant galaxy JADES GS-z13-1 (the red dot at center). This surprising galaxy emits light that has shifted into infrared wavelengths during its long journey across the cosmos. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Phill Cargile (CfA)/ Joris Witstok (Cambridge, University of Copenhagen)/ P. Jakobsen (University of Copenhagen)/ Alyssa Pagan (STScI)/ Mahdi Zamani (ESA/Webb)/ JADES Collaboration.

• The early universe was filled with a thick fog of neutral hydrogen. Even though the first stars and galaxies emitted copious amounts of ultraviolet light, that light struggled to pierce the fog.
• It took hundreds of millions of years for the neutral hydrogen to become ionized – electrons stripped from protons – allowing light to travel freely through space.
• But one galaxy with a bright, unexpected hydrogen emission caught astronomers by surprise. We see the galaxy JADES-GS-z13-1 just 330 million years after the Big Bang. It has a strong hydrogen emission line even though the cosmic fog should have absorbed it.

NASA published this original story on March 26, 2025. Edits by EarthSky.

Surprising galaxy in the early universe

Using NASA’s James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early universe. On March 26, 2025, an international team of astronomers said they’ve identified bright hydrogen emission from a galaxy in an unexpectedly early time in the universe’s history. The surprise finding challenges researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

Joris Witstok of the University of Cambridge in the United Kingdom and the Cosmic Dawn Center at the University of Copenhagen in Denmark led the international team. The researchers published their peer-reviewed study in the journal Nature on March 26, 2025.

The discovery of the surprising galaxy

The Webb telescope’s Near-Infrared Camera (NIRCam) discovered the incredibly distant galaxy JADES-GS-z13-1. We observe it as it existed just 330 million years after the Big Bang. Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift. A redshift measures a galaxy’s distance from Earth based on how its light has stretched out during its journey through expanding space.

The NIRCam imaging yielded an initial redshift estimate of 12.9. Seeking to confirm its extreme redshift, the researchers then observed the galaxy using Webb’s Near-Infrared Spectrograph (NIRSpec) instrument.

In the resulting spectrum, the scientists confirmed the redshift as 13.0. So this equates to seeing the galaxy just 330 million years after the Big Bang. That would be just a small fraction of the universe’s present age of 13.8 billion years old. But an unexpected feature stood out as well: one specific, distinctly bright wavelength of light, known as Lyman-alpha emission, radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the universe’s development.

We see galaxy JADES-GS-z13-1 as it was just 330 million years after the Big Bang. An international team of astronomers identified a powerful hydrogen emission from this galaxy at an unexpectedly early period in the universe’s history. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Phill Cargile (CfA)/ Joris Witstok (Cambridge, University of Copenhagen)/ P. Jakobsen (University of Copenhagen)/ Alyssa Pagan (STScI)/ Mahdi Zamani (ESA/Webb)/ JADES Collaboration.

Seeing through the fog

Roberto Maiolino, a team member from the University of Cambridge and University College London, explained:

The early universe was bathed in a thick fog of neutral hydrogen. Most of this haze was lifted in a process called reionization, which was completed about 1 billion years after the big bang. We see GS-z13-1 when the universe was only 330 million years old. Yet it shows a surprisingly clear, telltale signature of Lyman-alpha emission that can only be seen once the surrounding fog has fully lifted. This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise.

Before and during the era of reionization, there were immense amounts of neutral hydrogen fog. It surrounded galaxies, blocking any energetic ultraviolet light they emitted. Picture it similar to the filtering effect of colored glass. Until enough stars formed and could ionize the hydrogen gas, no such light – including Lyman-alpha emission – could escape from these fledgling galaxies to reach Earth. The confirmation of Lyman-alpha radiation from this galaxy, therefore, has great implications for our understanding of the early universe.

Kevin Hainline, a team member from the University of Arizona, said:

We really shouldn’t have found a galaxy like this, given our understanding of the way the universe has evolved. We could think of the early universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through. Yet here we see the beam of light from this galaxy piercing the veil. This fascinating emission line has huge ramifications for how and when the universe reionized.

Looking for answers

Scientists don’t yet know the source of the Lyman-alpha radiation from this galaxy. But it may include the first light from the earliest generation of stars to form in the universe. Witstok said:

The large bubble of ionized hydrogen surrounding this galaxy might have been created by a peculiar population of stars … much more massive, hotter and more luminous than stars formed at later epochs, and possibly representative of the first generation of stars.

A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility the team identified.

The galaxy JADES-GS-z13-1 has a redshift of z=13.05. That means we see it just 330 million years after the Big Bang. This graph shows its bright emission from hydrogen known as Lyman-alpha emission. This is surprising, because a dense fog of neutral hydrogen in the early universe should have absorbed it. Image via NASA/ ESA/ CSA/ S. Carniani (Scuola Normale Superiore)/ P. Jakobsen (University of Copenhagen)/ Joseph Olmsted (STScI).

Bottom line: Astronomers have discovered a surprising galaxy showing a bright hydrogen emission shining through the fog of the early universe.

Source: Witnessing the onset of reionization through Lyman-a emission at redshift 13

Via NASA

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The post Surprising galaxy shines through fog of the early universe first appeared on EarthSky.

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This image shows the incredibly distant galaxy JADES GS-z13-1 (the red dot at center). This surprising galaxy emits light that has shifted into infrared wavelengths during its long journey across the cosmos. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Phill Cargile (CfA)/ Joris Witstok (Cambridge, University of Copenhagen)/ P. Jakobsen (University of Copenhagen)/ Alyssa Pagan (STScI)/ Mahdi Zamani (ESA/Webb)/ JADES Collaboration.

• The early universe was filled with a thick fog of neutral hydrogen. Even though the first stars and galaxies emitted copious amounts of ultraviolet light, that light struggled to pierce the fog.
• It took hundreds of millions of years for the neutral hydrogen to become ionized – electrons stripped from protons – allowing light to travel freely through space.
• But one galaxy with a bright, unexpected hydrogen emission caught astronomers by surprise. We see the galaxy JADES-GS-z13-1 just 330 million years after the Big Bang. It has a strong hydrogen emission line even though the cosmic fog should have absorbed it.

NASA published this original story on March 26, 2025. Edits by EarthSky.

Surprising galaxy in the early universe

Using NASA’s James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early universe. On March 26, 2025, an international team of astronomers said they’ve identified bright hydrogen emission from a galaxy in an unexpectedly early time in the universe’s history. The surprise finding challenges researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

Joris Witstok of the University of Cambridge in the United Kingdom and the Cosmic Dawn Center at the University of Copenhagen in Denmark led the international team. The researchers published their peer-reviewed study in the journal Nature on March 26, 2025.

The discovery of the surprising galaxy

The Webb telescope’s Near-Infrared Camera (NIRCam) discovered the incredibly distant galaxy JADES-GS-z13-1. We observe it as it existed just 330 million years after the Big Bang. Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift. A redshift measures a galaxy’s distance from Earth based on how its light has stretched out during its journey through expanding space.

The NIRCam imaging yielded an initial redshift estimate of 12.9. Seeking to confirm its extreme redshift, the researchers then observed the galaxy using Webb’s Near-Infrared Spectrograph (NIRSpec) instrument.

In the resulting spectrum, the scientists confirmed the redshift as 13.0. So this equates to seeing the galaxy just 330 million years after the Big Bang. That would be just a small fraction of the universe’s present age of 13.8 billion years old. But an unexpected feature stood out as well: one specific, distinctly bright wavelength of light, known as Lyman-alpha emission, radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the universe’s development.

We see galaxy JADES-GS-z13-1 as it was just 330 million years after the Big Bang. An international team of astronomers identified a powerful hydrogen emission from this galaxy at an unexpectedly early period in the universe’s history. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Phill Cargile (CfA)/ Joris Witstok (Cambridge, University of Copenhagen)/ P. Jakobsen (University of Copenhagen)/ Alyssa Pagan (STScI)/ Mahdi Zamani (ESA/Webb)/ JADES Collaboration.

Seeing through the fog

Roberto Maiolino, a team member from the University of Cambridge and University College London, explained:

The early universe was bathed in a thick fog of neutral hydrogen. Most of this haze was lifted in a process called reionization, which was completed about 1 billion years after the big bang. We see GS-z13-1 when the universe was only 330 million years old. Yet it shows a surprisingly clear, telltale signature of Lyman-alpha emission that can only be seen once the surrounding fog has fully lifted. This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise.

Before and during the era of reionization, there were immense amounts of neutral hydrogen fog. It surrounded galaxies, blocking any energetic ultraviolet light they emitted. Picture it similar to the filtering effect of colored glass. Until enough stars formed and could ionize the hydrogen gas, no such light – including Lyman-alpha emission – could escape from these fledgling galaxies to reach Earth. The confirmation of Lyman-alpha radiation from this galaxy, therefore, has great implications for our understanding of the early universe.

Kevin Hainline, a team member from the University of Arizona, said:

We really shouldn’t have found a galaxy like this, given our understanding of the way the universe has evolved. We could think of the early universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through. Yet here we see the beam of light from this galaxy piercing the veil. This fascinating emission line has huge ramifications for how and when the universe reionized.

Looking for answers

Scientists don’t yet know the source of the Lyman-alpha radiation from this galaxy. But it may include the first light from the earliest generation of stars to form in the universe. Witstok said:

The large bubble of ionized hydrogen surrounding this galaxy might have been created by a peculiar population of stars … much more massive, hotter and more luminous than stars formed at later epochs, and possibly representative of the first generation of stars.

A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility the team identified.

The galaxy JADES-GS-z13-1 has a redshift of z=13.05. That means we see it just 330 million years after the Big Bang. This graph shows its bright emission from hydrogen known as Lyman-alpha emission. This is surprising, because a dense fog of neutral hydrogen in the early universe should have absorbed it. Image via NASA/ ESA/ CSA/ S. Carniani (Scuola Normale Superiore)/ P. Jakobsen (University of Copenhagen)/ Joseph Olmsted (STScI).

Bottom line: Astronomers have discovered a surprising galaxy showing a bright hydrogen emission shining through the fog of the early universe.

Source: Witnessing the onset of reionization through Lyman-a emission at redshift 13

Via NASA

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Coma Berenices: See how Leo the Lion lost his tail

To spot Coma Berenices, look behind Leo the Lion. Coma Berenices also contains a famous grouping of stars, the Coma star cluster.

The constellation of Coma Berenices

Coma Berenices is a constellation readily visible in spring skies that represents the hair of Queen Berenice. The constellation itself may not be very bright – you’ll need a dark sky to see most of its stars – but its location is easy enough to find. It trails Leo the Lion, with the Big Dipper high above it and Virgo with bright Spica below.

2025 EarthSky lunar calendar is available. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

View larger. | The constellation Coma Berenices via IAU/ Sky & Telescope/ Wikipedia (CC BY 3.0).

Finding Coma Berenices

How can you find it? One way is to use the famous constellation Leo the Lion, shown on our chart at the top of this post. It’s now in the east each evening and Leo is relatively easy to see. The front part of the Lion looks like a backward question mark, and the back part is a little triangle, which includes the star Denebola, marked on the chart above. The word Deneb in a star name always means tail, and this star marks the tail of Leo.

Do you know how to use the pointer stars in the Big Dipper to locate Polaris, the North Star? Instead of going northward from the pointer stars to Polaris, go southward to find the constellation Leo.

Now imagine that Leo is holding its tail out. In the place where you might see a “puff” at the end of the Lion’s tail, you’ll notice a fuzzy patch not too far away from Denebola. This is the constellation Coma Berenices, or Berenice’s Hair. In fact, the constellation Coma Berenices was once part of the constellation Leo.

The stars of Berenice’s Hair

The three main stars in Coma Berenices are Alpha, Beta, and Gamma Comae Berenices. They form the upper left portion of a square. The brightest of these stars is Beta Comae Berenices, at magnitude 4.2. It lies at the corner of the partial square.

Near the star Gamma Comae Berenices, at the top of the half-box, is a famous star cluster. Under dark skies, you can find Melotte 111, although it is more familiarly known as the Coma star cluster.

A tangle of stars

To see Melotte 111, the Coma star cluster, you need a dark sky. It is an open star cluster, a loose collection of stars held together by gravity.

Under a dark sky, the Coma star cluster can look like a glint on the sky. If you can’t spot this wispy and glimmering group of stars with the unaided eye, try binoculars. The cluster is actually fairly large, covering 5 degrees of the sky.

See the chart below.

The circle on this map shows you the location of the Coma star cluster in the constellation Coma Berenices. You’ll need dark skies to locate Coma Berenices – and the Coma star cluster – but you can use Leo to help you locate it. Chart via Stellarium.org. Used with permission.

Viewing Tip: To enhance your view of the Coma star cluster, take a paper towel tube or roll up some dark paper into a tube and place it to your eye. The tube will shield your eye from the glare of any ground lights. Binoculars or opera glasses will also lead to a better viewing experience.

The Coma star cluster is estimated to be about 288 light-years away and has at least 37 known stars that are 400 million years old. It is the third-closest open cluster to our Earth and sun. Only the Ursa Major cluster (the bowl stars of the Big Dipper) and the Hyades cluster (the head of Taurus the Bull) are closer.

The Coma galaxy cluster

There is another Coma cluster in the constellation of Coma Berenices, but that one is a cluster of galaxies. The names of the two are easily confused.

There’s also a vast cluster of galaxies located in the direction of the constellation Coma Berenices. Here is a majestic face-on spiral galaxy located deep within it. Read more about the Coma galaxy cluster. Image via NASA.

Formerly part of Leo the Lion

On old star charts like the one below, the tail of the constellation Leo the Lion has a curve. There’s a star there, Beta Leonis or Denebola, whose name means tail. Yet – on the dome of the sky – the Lion’s Tail used to extend out straight behind Leo, and the constellation of the Lion encompassed a much-larger area of the sky. The Greek-Egyptian astronomer Ptolemy and others considered a modern-day constellation – which we call Coma Berenices – as the tuft at the end of Leo’s tail. It was only a few hundred years ago that Coma Berenices became a separate constellation.

Leo the Lion, with the constellation Leo Minor, as it appears in Urania’s Mirror, a set of cards by Sidney Hall depicting the constellations published in 1825. Image via U.S. Library of Congress/ Wikimedia Commons (public domain).

Mythology of Coma Berenices

The official constellation is relatively new, but the lore behind the constellation is old. The story goes that an ancient Egyptian queen, Berenice, feared for her husband’s life as he went into battle. She prayed to Aphrodite, promising to cut off her long, luxurious curls if the king returned safely. He did, and Berenice kept her promise and cut off her hair, placing it as a sacrifice on Aphrodite’s altar.

But the next day the hair was gone!

The enraged king was angry that the temple priests had not protected the precious locks. A quick-thinking astronomer saved the day, or rather night, by pointing to the cascading stars at the end of Leo’s tail. He told the king that these were the queen’s tresses placed in the sky by Aphrodite for all to see.

This appeased the king and queen, and saved the priests from a beheading.

Thus, Leo lost his tail … and, ultimately, we gained a constellation.

The constellations of Coma Berenices (Berenice’s Hair), Boötes the Herdsman, and Canes Venatici the Hunting Dogs. Image via Wikipedia (public domain).

Bottom line: Coma Berenices is the constellation of Queen Berenice’s Hair. It used to be the tail of Leo the Lion before it became its own constellation. It contains a large open star cluster easily viewed in binoculars.

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To spot Coma Berenices, look behind Leo the Lion. Coma Berenices also contains a famous grouping of stars, the Coma star cluster.

The constellation of Coma Berenices

Coma Berenices is a constellation readily visible in spring skies that represents the hair of Queen Berenice. The constellation itself may not be very bright – you’ll need a dark sky to see most of its stars – but its location is easy enough to find. It trails Leo the Lion, with the Big Dipper high above it and Virgo with bright Spica below.

2025 EarthSky lunar calendar is available. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

View larger. | The constellation Coma Berenices via IAU/ Sky & Telescope/ Wikipedia (CC BY 3.0).

Finding Coma Berenices

How can you find it? One way is to use the famous constellation Leo the Lion, shown on our chart at the top of this post. It’s now in the east each evening and Leo is relatively easy to see. The front part of the Lion looks like a backward question mark, and the back part is a little triangle, which includes the star Denebola, marked on the chart above. The word Deneb in a star name always means tail, and this star marks the tail of Leo.

Do you know how to use the pointer stars in the Big Dipper to locate Polaris, the North Star? Instead of going northward from the pointer stars to Polaris, go southward to find the constellation Leo.

Now imagine that Leo is holding its tail out. In the place where you might see a “puff” at the end of the Lion’s tail, you’ll notice a fuzzy patch not too far away from Denebola. This is the constellation Coma Berenices, or Berenice’s Hair. In fact, the constellation Coma Berenices was once part of the constellation Leo.

The stars of Berenice’s Hair

The three main stars in Coma Berenices are Alpha, Beta, and Gamma Comae Berenices. They form the upper left portion of a square. The brightest of these stars is Beta Comae Berenices, at magnitude 4.2. It lies at the corner of the partial square.

Near the star Gamma Comae Berenices, at the top of the half-box, is a famous star cluster. Under dark skies, you can find Melotte 111, although it is more familiarly known as the Coma star cluster.

A tangle of stars

To see Melotte 111, the Coma star cluster, you need a dark sky. It is an open star cluster, a loose collection of stars held together by gravity.

Under a dark sky, the Coma star cluster can look like a glint on the sky. If you can’t spot this wispy and glimmering group of stars with the unaided eye, try binoculars. The cluster is actually fairly large, covering 5 degrees of the sky.

See the chart below.

The circle on this map shows you the location of the Coma star cluster in the constellation Coma Berenices. You’ll need dark skies to locate Coma Berenices – and the Coma star cluster – but you can use Leo to help you locate it. Chart via Stellarium.org. Used with permission.

Viewing Tip: To enhance your view of the Coma star cluster, take a paper towel tube or roll up some dark paper into a tube and place it to your eye. The tube will shield your eye from the glare of any ground lights. Binoculars or opera glasses will also lead to a better viewing experience.

The Coma star cluster is estimated to be about 288 light-years away and has at least 37 known stars that are 400 million years old. It is the third-closest open cluster to our Earth and sun. Only the Ursa Major cluster (the bowl stars of the Big Dipper) and the Hyades cluster (the head of Taurus the Bull) are closer.

The Coma galaxy cluster

There is another Coma cluster in the constellation of Coma Berenices, but that one is a cluster of galaxies. The names of the two are easily confused.

There’s also a vast cluster of galaxies located in the direction of the constellation Coma Berenices. Here is a majestic face-on spiral galaxy located deep within it. Read more about the Coma galaxy cluster. Image via NASA.

Formerly part of Leo the Lion

On old star charts like the one below, the tail of the constellation Leo the Lion has a curve. There’s a star there, Beta Leonis or Denebola, whose name means tail. Yet – on the dome of the sky – the Lion’s Tail used to extend out straight behind Leo, and the constellation of the Lion encompassed a much-larger area of the sky. The Greek-Egyptian astronomer Ptolemy and others considered a modern-day constellation – which we call Coma Berenices – as the tuft at the end of Leo’s tail. It was only a few hundred years ago that Coma Berenices became a separate constellation.

Leo the Lion, with the constellation Leo Minor, as it appears in Urania’s Mirror, a set of cards by Sidney Hall depicting the constellations published in 1825. Image via U.S. Library of Congress/ Wikimedia Commons (public domain).

Mythology of Coma Berenices

The official constellation is relatively new, but the lore behind the constellation is old. The story goes that an ancient Egyptian queen, Berenice, feared for her husband’s life as he went into battle. She prayed to Aphrodite, promising to cut off her long, luxurious curls if the king returned safely. He did, and Berenice kept her promise and cut off her hair, placing it as a sacrifice on Aphrodite’s altar.

But the next day the hair was gone!

The enraged king was angry that the temple priests had not protected the precious locks. A quick-thinking astronomer saved the day, or rather night, by pointing to the cascading stars at the end of Leo’s tail. He told the king that these were the queen’s tresses placed in the sky by Aphrodite for all to see.

This appeased the king and queen, and saved the priests from a beheading.

Thus, Leo lost his tail … and, ultimately, we gained a constellation.

The constellations of Coma Berenices (Berenice’s Hair), Boötes the Herdsman, and Canes Venatici the Hunting Dogs. Image via Wikipedia (public domain).

Bottom line: Coma Berenices is the constellation of Queen Berenice’s Hair. It used to be the tail of Leo the Lion before it became its own constellation. It contains a large open star cluster easily viewed in binoculars.

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Here’s how to see the Lunar X and V at 1st-quarter moon

View at EarthSky Community Photos. | Kannan A in Singapore wrote on April 19, 2021: “Upon a close look at the moon tonight, I realized that the Lunar X and Lunar V were clearly visible. These are transient lunar features visible on the lunar surface for about 4 hours once a month. They are most striking when they are visible on the shadow side of the terminator. But they will remain visible against the lunar surface even after the terminator has moved because they are brighter than the surrounding area.” Thank you, Kannan!

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Lunar X and Lunar V

Have you heard of Lunar X and Lunar V? They are famous optical features on the moon, visible through telescopes. So, when the moon’s terminator – or line between light and dark on the moon – is located in just the right place, you can see a letter X and a letter V on the moon’s surface. Are they a sign of an alien visitation? No. Rather, Lunar X is a great example of how lighting and topography can combine on a planet or moon to produce a pattern that seems familiar to the human eye.

In reality, the illusion of Lunar X is created by sunlight falling on the rims/ridges between the craters La Caille, Bianchini and Purbach. The V is caused by light illuminating crater Ukert, along with several smaller craters.

View at EarthSky Community Photos. | Radu Anghel captured this image from Bacau, Romania, on April 27, 2023. Radu wrote: “X and V from tonight’s moon.” Thank you, Radu! Learn how to see Lunar X and V below.

When are they visible?

Basically, people see Lunar X and Lunar V at each cycle of the moon, but only for a short time. In fact, they’re observable for about four hours around the 1st quarter moon phase.

View at EarthSky Community Photos. | Matthew Chin from Hong Kong, China, shared this image of the moon, where Lunar X and Lunar V are visible, on January 18, 2024. Thank you, Matthew!

Bottom line: Lunar X and Lunar V are optical features on the moon. They are visible through a telescope for several hours around the time of the 1st quarter moon.

The post Here’s how to see the Lunar X and V at 1st-quarter moon first appeared on EarthSky.

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View at EarthSky Community Photos. | Kannan A in Singapore wrote on April 19, 2021: “Upon a close look at the moon tonight, I realized that the Lunar X and Lunar V were clearly visible. These are transient lunar features visible on the lunar surface for about 4 hours once a month. They are most striking when they are visible on the shadow side of the terminator. But they will remain visible against the lunar surface even after the terminator has moved because they are brighter than the surrounding area.” Thank you, Kannan!

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Lunar X and Lunar V

Have you heard of Lunar X and Lunar V? They are famous optical features on the moon, visible through telescopes. So, when the moon’s terminator – or line between light and dark on the moon – is located in just the right place, you can see a letter X and a letter V on the moon’s surface. Are they a sign of an alien visitation? No. Rather, Lunar X is a great example of how lighting and topography can combine on a planet or moon to produce a pattern that seems familiar to the human eye.

In reality, the illusion of Lunar X is created by sunlight falling on the rims/ridges between the craters La Caille, Bianchini and Purbach. The V is caused by light illuminating crater Ukert, along with several smaller craters.

View at EarthSky Community Photos. | Radu Anghel captured this image from Bacau, Romania, on April 27, 2023. Radu wrote: “X and V from tonight’s moon.” Thank you, Radu! Learn how to see Lunar X and V below.

When are they visible?

Basically, people see Lunar X and Lunar V at each cycle of the moon, but only for a short time. In fact, they’re observable for about four hours around the 1st quarter moon phase.

View at EarthSky Community Photos. | Matthew Chin from Hong Kong, China, shared this image of the moon, where Lunar X and Lunar V are visible, on January 18, 2024. Thank you, Matthew!

Bottom line: Lunar X and Lunar V are optical features on the moon. They are visible through a telescope for several hours around the time of the 1st quarter moon.

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Birthplaces of new planets come in many different sizes

View larger. | These are the 73 protoplanetary disks – or planet-forming disks – that ALMA observed in the Lupus region (2 of the images contain binary stars). New research shows that such disks – the birthplaces of new planets – come in a much wider range of sizes than previously thought. The size of Neptune’s orbit is shown at the bottom right for scale. AU means astronomical unit. One AU is the average distance from the sun to Earth. Image via Guerra-Alvarado et al./ Astronomie.nl.

• Protoplanetary disks are huge rotating disks of gas and dust around newborn stars. They are the birthplaces of new planets.
• Astronomers had thought almost all protoplanetary disks are big, about the size of our solar system or larger. But new observations show they come in a wide range of sizes.
• About 2/3 of protoplanetary disks are much smaller than first thought. They tend to form around young red dwarf stars and also lack the gaps seen in larger disks, where giant planets form. This means our own solar system’s original disk was not typical of most stars.

What is a typical protoplanetary disk?

Planets are born in disks of dust and gas around newborn stars called protoplanetary disks. Many of those disks are immense, as large as our solar system or more. In fact, astronomers had thought that most, if not nearly all, such disks are this size. But a team of international astronomers said on March 26, 2025, that they’ve used the Atacama Large Millimeter/submillimeter Array (ALMA) to take a closer look at 73 protoplanetary disks in the Lupus star-forming region. And they found about 2/3 of those disks are much smaller than first thought. Unlike larger disks, the smaller ones don’t have gaps or rings. So what is a typical protoplanetary disk? Or is there no such thing?

The researchers’ new paper has been accepted for publication in Astronomy & Astrophysics. You can read a preprint version on arXiv submitted on March 25, 2025.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

The birthplaces of new planets

Planet-forming disks – or protoplanetary disks – are huge swirling disks of dust and gas around young stars. They are the birthplaces of new planets. Astronomers have imaged hundreds of them in recent years. How big are they? Until now, most of the disks that astronomers found have been enormous. If centered around our sun, they would extend past the orbit of Neptune.

Astronomers thought these were typical for protoplanetary disks. But that seems not to be the case after all.

Artist’s rendering of a protoplanetary (planet-forming) disk. Video via ESO/ L. Calçada.

Planet-forming disks come in many sizes, big and small

Osmar Manuel Guerra-Alvarado, Mariana Belen Sanchez and Nienke van der Marel at the Leiden Observatory in The Netherlands led the new study. Using ALMA in 2023 and 2024, they imaged all of the known 73 disks in Lupus, a star-forming region 400 light-years away in the constellation Lupus the Wolf. They imaged the disks with the highest possible resolution of 0.030 arcseconds. And they found something surprising.

Only about 1/3 of the disks were of the gargantuan variety. The rest – 2/3 of the 73 disks – were much smaller. They would only extend about as far as the orbit of Jupiter, if placed around our sun. That’s about 6 astronomical units (AU). The smallest one was a scant 0.6 AU in size. One AU is the average distance from the sun to Earth, 93 million miles (150 million km). Guerra-Alvarado said:

These results completely change our view of what a ‘typical’ protoplanetary disk looks like. Only the brightest disks, which are the easiest to observe, show large-scale gaps, whereas compact disks without such substructures are actually much more common.

Lead author Osmar Manuel Guerra-Alvarado at Leiden University in The Netherlands. Image via Leiden University.

Small disks, small stars and super-Earths

Notably, most of the smaller disks were around small stars called red dwarfs. In fact, these low-mass stars are the most common type of star in our Milky Way galaxy. This suggests there should be many more small disks waiting to be discovered.

In addition, the researchers found these smaller disks should be ideal for super-Earth type exoplanets to form in. Those are rocky worlds larger and more massive than Earth, but smaller and less massive than Neptune. And, indeed, astronomers have found many super-Earths orbiting red dwarf stars. Sanchez said:

The observations also show that these compact discs could have optimal conditions for the formation of so-called super-Earths, as most of the dust is close to the star, where super-Earths are typically found.

The results also highlight a difference between our solar system and those that form from smaller protoplanetary disks. While our solar system has a wide range of planets, there is no super-Earth. Since the protoplanetary disk the solar system formed from was of the larger variety, there are now gas giant planets, but no super-Earths.

View larger. | Artist’s illustration of a large protoplanetary disk. The gaps are where new planets are forming. Image via ESO/ L. Calçada.

Missing gaps

The observations of the Lupus disks also provided another clue about planetary formation. Studies of full-grown stars have shown that most stars do not have giant gas planets. Smaller planets, like super-Earths and others, are more common. In fact, astronomers think super-Earths are the most common type of planet in our galaxy. This is also consistent with the new ALMA observations. Most of the smaller disks don’t have gaps in them. Those gaps are where new planets form. They gather surrounding material as they grow, clearing their orbit in the disk. This creates the gaps. As Van der Marel noted:

The discovery that the majority of the small disks do not show gaps, implies that the majority of stars do not host giant planets. This is consistent with what we see in exoplanet populations around full-grown stars. These observations link the disk population directly to the exoplanet population.

Not so typical after all

Overall, the observations show that the “typical” protoplanetary disks are not so typical after all. They are both big and small, with gaps and without gaps. Van der Marel said:

The research shows that we’ve been wrong for a long time about how a typical disk looks. Clearly, we’ve been biased toward the brightest and largest disks. Now we finally have a full overview of disks of all sizes.

Bottom line: Researchers using the ALMA observatory have found that protoplanetary disks – the birthplaces of new planets – vary in size much more than previously thought.

Source: A high-resolution survey of protoplanetary disks in Lupus and the nature of compact disks

Via Astronomie.nl

Read more: 1st planet-forming disk found in another galaxy

Read more: Astonishing image of planet-forming disk from ALMA

The post Birthplaces of new planets come in many different sizes first appeared on EarthSky.

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View larger. | These are the 73 protoplanetary disks – or planet-forming disks – that ALMA observed in the Lupus region (2 of the images contain binary stars). New research shows that such disks – the birthplaces of new planets – come in a much wider range of sizes than previously thought. The size of Neptune’s orbit is shown at the bottom right for scale. AU means astronomical unit. One AU is the average distance from the sun to Earth. Image via Guerra-Alvarado et al./ Astronomie.nl.

• Protoplanetary disks are huge rotating disks of gas and dust around newborn stars. They are the birthplaces of new planets.
• Astronomers had thought almost all protoplanetary disks are big, about the size of our solar system or larger. But new observations show they come in a wide range of sizes.
• About 2/3 of protoplanetary disks are much smaller than first thought. They tend to form around young red dwarf stars and also lack the gaps seen in larger disks, where giant planets form. This means our own solar system’s original disk was not typical of most stars.

What is a typical protoplanetary disk?

Planets are born in disks of dust and gas around newborn stars called protoplanetary disks. Many of those disks are immense, as large as our solar system or more. In fact, astronomers had thought that most, if not nearly all, such disks are this size. But a team of international astronomers said on March 26, 2025, that they’ve used the Atacama Large Millimeter/submillimeter Array (ALMA) to take a closer look at 73 protoplanetary disks in the Lupus star-forming region. And they found about 2/3 of those disks are much smaller than first thought. Unlike larger disks, the smaller ones don’t have gaps or rings. So what is a typical protoplanetary disk? Or is there no such thing?

The researchers’ new paper has been accepted for publication in Astronomy & Astrophysics. You can read a preprint version on arXiv submitted on March 25, 2025.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

The birthplaces of new planets

Planet-forming disks – or protoplanetary disks – are huge swirling disks of dust and gas around young stars. They are the birthplaces of new planets. Astronomers have imaged hundreds of them in recent years. How big are they? Until now, most of the disks that astronomers found have been enormous. If centered around our sun, they would extend past the orbit of Neptune.

Astronomers thought these were typical for protoplanetary disks. But that seems not to be the case after all.

Artist’s rendering of a protoplanetary (planet-forming) disk. Video via ESO/ L. Calçada.

Planet-forming disks come in many sizes, big and small

Osmar Manuel Guerra-Alvarado, Mariana Belen Sanchez and Nienke van der Marel at the Leiden Observatory in The Netherlands led the new study. Using ALMA in 2023 and 2024, they imaged all of the known 73 disks in Lupus, a star-forming region 400 light-years away in the constellation Lupus the Wolf. They imaged the disks with the highest possible resolution of 0.030 arcseconds. And they found something surprising.

Only about 1/3 of the disks were of the gargantuan variety. The rest – 2/3 of the 73 disks – were much smaller. They would only extend about as far as the orbit of Jupiter, if placed around our sun. That’s about 6 astronomical units (AU). The smallest one was a scant 0.6 AU in size. One AU is the average distance from the sun to Earth, 93 million miles (150 million km). Guerra-Alvarado said:

These results completely change our view of what a ‘typical’ protoplanetary disk looks like. Only the brightest disks, which are the easiest to observe, show large-scale gaps, whereas compact disks without such substructures are actually much more common.

Lead author Osmar Manuel Guerra-Alvarado at Leiden University in The Netherlands. Image via Leiden University.

Small disks, small stars and super-Earths

Notably, most of the smaller disks were around small stars called red dwarfs. In fact, these low-mass stars are the most common type of star in our Milky Way galaxy. This suggests there should be many more small disks waiting to be discovered.

In addition, the researchers found these smaller disks should be ideal for super-Earth type exoplanets to form in. Those are rocky worlds larger and more massive than Earth, but smaller and less massive than Neptune. And, indeed, astronomers have found many super-Earths orbiting red dwarf stars. Sanchez said:

The observations also show that these compact discs could have optimal conditions for the formation of so-called super-Earths, as most of the dust is close to the star, where super-Earths are typically found.

The results also highlight a difference between our solar system and those that form from smaller protoplanetary disks. While our solar system has a wide range of planets, there is no super-Earth. Since the protoplanetary disk the solar system formed from was of the larger variety, there are now gas giant planets, but no super-Earths.

View larger. | Artist’s illustration of a large protoplanetary disk. The gaps are where new planets are forming. Image via ESO/ L. Calçada.

Missing gaps

The observations of the Lupus disks also provided another clue about planetary formation. Studies of full-grown stars have shown that most stars do not have giant gas planets. Smaller planets, like super-Earths and others, are more common. In fact, astronomers think super-Earths are the most common type of planet in our galaxy. This is also consistent with the new ALMA observations. Most of the smaller disks don’t have gaps in them. Those gaps are where new planets form. They gather surrounding material as they grow, clearing their orbit in the disk. This creates the gaps. As Van der Marel noted:

The discovery that the majority of the small disks do not show gaps, implies that the majority of stars do not host giant planets. This is consistent with what we see in exoplanet populations around full-grown stars. These observations link the disk population directly to the exoplanet population.

Not so typical after all

Overall, the observations show that the “typical” protoplanetary disks are not so typical after all. They are both big and small, with gaps and without gaps. Van der Marel said:

The research shows that we’ve been wrong for a long time about how a typical disk looks. Clearly, we’ve been biased toward the brightest and largest disks. Now we finally have a full overview of disks of all sizes.

Bottom line: Researchers using the ALMA observatory have found that protoplanetary disks – the birthplaces of new planets – vary in size much more than previously thought.

Source: A high-resolution survey of protoplanetary disks in Lupus and the nature of compact disks

Via Astronomie.nl

Read more: 1st planet-forming disk found in another galaxy

Read more: Astonishing image of planet-forming disk from ALMA

The post Birthplaces of new planets come in many different sizes first appeared on EarthSky.

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The South Pole begins its 6 months of darkness

On March 20, 2025, NOAA’s South Pole Atmospheric Baseline Observatory saw the final glimpse of sunlight before 6 months of darkness. In this image, a wave of snow frames Dark Sector telescopes. Image via Ian Crocker/ NOAA.

• Earth passed the March equinox on March 20, 2025. The Northern Hemisphere is beginning spring while the Southern Hemisphere is entering autumn.
• The South Pole saw the sunset on the March equinox. For the next six months, Antarctica will undergo a perpetual night.
• Over the course of a year, there is only one sunrise and one sunset for the South Pole. As a result, researchers who do one-year tours of duty will spend half the time in daylight and half in darkness.

NOAA published this original article on April 2, 2025. Edits by EarthSky.

The South Pole begins its 6 months of darkness

In the Northern Hemisphere, March 20 signals the start of spring. It’s the start of fall in the Southern Hemisphere, where researchers and staff at NOAA’s South Pole Observatory recently witnessed the fading light of the sun and the start of six months of darkness. Ian Crocker, a South Pole station technician with NOAA’s Global Monitoring Laboratory, said:

As the sun gets low on the horizon and temperatures continue to drop, the sky transitions from the bright, crisp blue we had seen since our arrival many months ago, to slowly reveal shades of green and orange, pink and violet.

Crocker and his colleagues will help continue NOAA’s mission at the observatory throughout the 2025 Antarctic winter, including taking measurements of ozone, greenhouse gases, aerosols and solar radiation.

Even now, a couple weeks after the equinox, the South Pole is still enjoying twilight. Check out the livecam at the South Pole.

NOAA’s South Pole Atmospheric Research Observatory and a kaleidoscopic sunset. Image via Ian Crocker/ NOAA.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

1 sunrise and 1 sunset

NOAA’s South Pole Observatory is part of the National Science Foundation’s Amundsen-Scott South Pole Station. It’s located at the geographic South Pole on the Antarctic plateau at an elevation of 2,837 meters (9,307 ft) above sea level. For nine months each year, no flights go in or out of the research station because aircraft systems don’t work in such cold conditions.

GML staff members have a one-year tour of duty at the observatory. However, they experience just one sunrise and one sunset. So consequently, they won’t see the sun rise for six months.

Crocker shares what that experience means to him:

The stark, surreal beauty of this place and this time of transition is unlike any other. It elicits feelings of wondrous awe, deep gratitude, a contemplative curiosity about the dark months ahead and knowing that this experience will leave an imprint on our lives forever.

A green sky and nearly full moon above the Dark Sector and Ceremonial South Pole, on March 17, 2025. The Dark Sector is a designated area where light and electromagnetic interference are minimized to support sensitive scientific instruments. Image via Ian Crocker/ NOAA.

Bottom line: On the March equinox, researchers at the South Pole saw the sunset and entered into six months of darkness. During their one year in Antarctica, they will only see one sunrise and one sunset.

Via NOAA

Read more: Bird fossil hints Antarctica was a refuge from killer asteroid

The post The South Pole begins its 6 months of darkness first appeared on EarthSky.

from EarthSky https://ift.tt/twUeRCX

On March 20, 2025, NOAA’s South Pole Atmospheric Baseline Observatory saw the final glimpse of sunlight before 6 months of darkness. In this image, a wave of snow frames Dark Sector telescopes. Image via Ian Crocker/ NOAA.

• Earth passed the March equinox on March 20, 2025. The Northern Hemisphere is beginning spring while the Southern Hemisphere is entering autumn.
• The South Pole saw the sunset on the March equinox. For the next six months, Antarctica will undergo a perpetual night.
• Over the course of a year, there is only one sunrise and one sunset for the South Pole. As a result, researchers who do one-year tours of duty will spend half the time in daylight and half in darkness.

NOAA published this original article on April 2, 2025. Edits by EarthSky.

The South Pole begins its 6 months of darkness

In the Northern Hemisphere, March 20 signals the start of spring. It’s the start of fall in the Southern Hemisphere, where researchers and staff at NOAA’s South Pole Observatory recently witnessed the fading light of the sun and the start of six months of darkness. Ian Crocker, a South Pole station technician with NOAA’s Global Monitoring Laboratory, said:

As the sun gets low on the horizon and temperatures continue to drop, the sky transitions from the bright, crisp blue we had seen since our arrival many months ago, to slowly reveal shades of green and orange, pink and violet.

Crocker and his colleagues will help continue NOAA’s mission at the observatory throughout the 2025 Antarctic winter, including taking measurements of ozone, greenhouse gases, aerosols and solar radiation.

Even now, a couple weeks after the equinox, the South Pole is still enjoying twilight. Check out the livecam at the South Pole.

NOAA’s South Pole Atmospheric Research Observatory and a kaleidoscopic sunset. Image via Ian Crocker/ NOAA.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

1 sunrise and 1 sunset

NOAA’s South Pole Observatory is part of the National Science Foundation’s Amundsen-Scott South Pole Station. It’s located at the geographic South Pole on the Antarctic plateau at an elevation of 2,837 meters (9,307 ft) above sea level. For nine months each year, no flights go in or out of the research station because aircraft systems don’t work in such cold conditions.

GML staff members have a one-year tour of duty at the observatory. However, they experience just one sunrise and one sunset. So consequently, they won’t see the sun rise for six months.

Crocker shares what that experience means to him:

The stark, surreal beauty of this place and this time of transition is unlike any other. It elicits feelings of wondrous awe, deep gratitude, a contemplative curiosity about the dark months ahead and knowing that this experience will leave an imprint on our lives forever.

A green sky and nearly full moon above the Dark Sector and Ceremonial South Pole, on March 17, 2025. The Dark Sector is a designated area where light and electromagnetic interference are minimized to support sensitive scientific instruments. Image via Ian Crocker/ NOAA.

Bottom line: On the March equinox, researchers at the South Pole saw the sunset and entered into six months of darkness. During their one year in Antarctica, they will only see one sunrise and one sunset.

Via NOAA

Read more: Bird fossil hints Antarctica was a refuge from killer asteroid

The post The South Pole begins its 6 months of darkness first appeared on EarthSky.

from EarthSky https://ift.tt/twUeRCX