Small asteroid impact today near Australia

The Mount Lemmon Observatory survey has spotted a new asteroid, less than 1 meter across (less than 3 feet across) that’s headed for Earth. The impact should happen in Earth’s atmosphere near northwest Australia at 16:07 UTC (11:07 a.m. CDT). At that time near Australia the skies should be dark, so people in the area could see a bright flash of the incoming meteor.

At the moment, the asteroid has the name CERNQ52.

This is the 13th time we’ve discovered an asteroid before impact.

Richard Moissl, the Head of Planetary Defense for ESA, wrote on social media:

INCOMING! Our systems have calculated an atmospheric entry in the timeframe between 16:00-16:30 UTC of a harmless object discovered by Mt Lemmon survey with a diameter of ~0.8 m northwest of Australia over the ocean. The impact will likely cause a bright meteor.

Adrien Coffinet, a member of the Minor Planet Mailing List, wrote:

If I’m not wrong, this will be the first Aten asteroid (a < 1 AU) detected in space before impact. All the previous impactors detected in space before impact were Apollo asteroids (a > 1 AU).

Aten asteroids are those that have an orbit inside Earth’s, so under 1 astronomical unit (AU). Apollo asteroids are those that are farther from the sun than Earth on average.

Report the meteor if you see it

If you live in the area and see the bright flash of the meteor from the asteroid impact, you can report it with the International Meteor Organization. And if you capture an image of it, share it with us at EarthSky Community Photos!

? ASTEROID ATMOSPHERIC ENTRY ALERT ?A freshly discovered (08h45min UT, Sept. 6) small (~0,8 m diameter) asteroid (CERNQ52) is in a trajectory that will direct it into the Earth atmosphere, over Indian ocean today (Sept. 6) around 16h 35min UT. Stay tuned for more updates!

— International Meteor Organization (@imometeors.bsky.social) 2026-09-06T10:45:09.571Z

Bottom line: A small asteroid impact will occur in the next few hours near northwest Australia. The meteor should harmlessly burn up in Earth’s atmosphere and poses no danger.

Read more: How big are asteroids? Compare sizes in this video

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• Antarctica is home to a variety of plant and animal life, despite the extreme cold. What about microbes?
• Researchers at University of Colorado have discovered microbes in Antarctica soil that are not known to exist anywhere else on Earth.
• The microbes are uniquely adapted to the extreme conditions in Antarctica.

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Microbes in Antarctica

Antarctica is a unique environment on Earth, with its own plant and animal life such as penguins. But what about microbes? We think of microbes as being everywhere. That is, the same types of microbes all over the planet. But it turns out that Antarctica is unique that way, too. On August 31, 2026, researchers at CIRES at University of Colorado Boulder said that they’ve discovered microbes in Antarctica that are found nowhere else on Earth. And indeed, the microbial critters are uniquely adapted to the extreme conditions in Antarctica.

Notably, these are specific microbes, not all microbes in Antarctica. But it shows that some life in Antarctica can be different from the rest of the world.

The researchers published the new peer-reviewed findings in Proceedings of the National Academy of Sciences (PNAS) on August 31, 2026.

Microbes found in Antarctica's soil are unique to the continent. In a new study, the researchers analyzed soil samples from Antarctica and similar cold, dry environments like the Tibetan Plateau, Svalbard in the Arctic, and Chile’s Atacama Desert. @pnas.bsky buff.ly/Ds9MBDm

— CIRES (@cires.colorado.edu) 2026-08-31T19:10:56.326Z

Everything is everywhere … or not

We know that microbes can be found virtually everywhere on Earth. Even Antarctica. But there’s a misperception that the same microbes are everywhere.

Nick Dragone at University of Colorado Boulder led the new study. He said:

There is a long-standing assumption in microbiology that ‘everything is everywhere.’ Antarctica has often been viewed as a possible exception, and our findings support that idea. Some Antarctic soil microbes appear to be distinct from those found in soils elsewhere around the world.

And finding microbes that are endemic – living naturally in only one specific geographic location – in Antarctica has implications for how scientists think microbial life spreads around the planet. Microbes can disperse great distances on winds or ocean currents.

Co-author and CIRES Fellow and Director of the Center for Microbial Exploration Noah Fierer added:

If we do find we’re looking for endemic microorganisms, a good place to start is Antarctica, because it’s an entire continent that is geographically isolated. It also has unique conditions not typically found in other soil environments. Cold is the obvious one, but also super dry; Antarctica is a desert.

The search is on

The team searched for and collected soil samples from across Antarctica, which was essential to the study.

The researchers tested the soil samples from Antarctica and similar cold, dry environments such as the Tibetan Plateau, Svalbard in the Arctic and Chile’s Atacama Desert. Overall, this included over 100 Antarctic strains in the Arthrobacter group and nearly 500 strains from other locations worldwide. These particular strains are common in soils from Antarctica to Colorado to the tropics. Co-author Byron Adams at Brigham Young University said:

Arthrobacter as a group may be found all over the planet, but when we look closely at individual strains, just like penguins, Antarctica clearly has its own distinctive biological history.

Fierer said:

We already knew that a broad diversity of microbes can survive the inhospitable conditions of Antarctica. Now we know that some of those microbes are also unique to Antarctica and are uniquely adapted to life on the southern continent.

Genomes and simulating Antarctica

The researchers conducted the laboratory studies in two steps. First they sequenced the genomes – the genetic information of organisms – of the Arthrobacter strains. They compared the genomic traits of the bacteria to other samples collected from around the world. It was the genomic traits that showed that these specific microbes were unique to Antarctica. In fact, 90% of the strains are found nowhere else on Earth.

The team then simulated the conditions of Antarctica in the lab, such as the extreme cold and dryness. Then, they grew strains of Arthrobacter in Petri dishes. These strains tended to grow more slowly than the other test strains. But they did survive and grew.

Ancient birds in Antarctica

Speaking of life in Antarctica, last year scientists said that the fossil of an ancient bird called Vegavis iaai showed how many birds survived the asteroid impact that killed off the dinosaurs about 66 million years ago. The great distance from the impact site in Mexico and Antarctica could have allowed some birds to survive the upheaval.

At the time, Antarctica was ice-free and had a temperate climate with forests of conifers, cycads and ferns. So Vegavis lived among a diverse fauna of other birds, non-avian dinosaurs, insects, reptiles, pterosaurs and small early mammals.

Bottom line: Researchers have discovered that some microbes in Antarctica are unique to the icy continent and are found nowhere else on Earth.

Source: Evidence for endemism and local adaptation in Antarctic soil bacteria

Via CIRES/ University of Colorado

Read more: Stardust in Antarctica shows Earth crossed a supernova cloud

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

The post These microbes in Antarctica don’t live anywhere else first appeared on EarthSky.

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We in the United States celebrate Labor Day on the 1st Monday of September every year. It all began with a parade in New York City in 1882, organized by labor unions. The idea of celebrating workers quickly caught on, and as many as 30 states recognized Labor Day before it became a federal holiday in 1894. Canada also celebrates Labor Day on the 1st Monday in September. Other countries around the world celebrate their workers with International Workers’ Day on May Day (May 1) every year.

The history of Labor Day

The late 1800s featured burgeoning trade union and labor movements. Credit for the origin of the Labor Day holiday goes to two men, Matthew Maguire and Peter McGuire. Matthew was secretary of the Central Labor Union in New York. Peter was the vice president of the American Federation of Labor. Some stories say these men with similar last names were actually brothers. In any case, they chose a date midway between the Fourth of July and Thanksgiving. The weather would be ideal for parades and picnics, two events we still enjoy on Labor Day today.

Labor Day celebrations and traditions

Many Americans take their long weekend to celebrate the unofficial end of summer. And kids enjoy a last hurrah as they must return to school around this time. The meteorological start of fall is September 1, while the astronomical start of fall in the Northern Hemisphere is usually September 22 or 23.

Ironically, with people having a day free from work, businesses wanted to take advantage of that time off to lure them into stores. And so, the Labor Day Sale was born. Thus, many people in the retail industry see Labor Day not as a day off but as a busy day of work.

US federal holidays

Occasionally, people get Memorial Day confused with Labor Day. One marks the unofficial start of summer while the other marks the unofficial end of summer. Of course, both are federal holidays celebrated with a Monday off work, one at the end of May and the other at the beginning of September. But Memorial Day is a commemoration for fallen U.S. soldiers, while Labor Day is a celebration of American workers. (Memorial Day should also not be confused with Veterans Day or Armed Forces Day. Veterans Day is a day to honor U.S. military veterans. Armed Forces Day celebrates current U.S. military service men and women.)

There are 12 permanent federal holidays in the United States:

• New Year’s Day
• Martin Luther King Jr.’s Birthday
• Inauguration Day (every 4 years)
• George Washington’s Birthday (some states call it Presidents Day)
• Memorial Day
• Juneteenth National Independence Day
• Independence Day
• Labor Day
• Columbus Day
• Veterans Day
• Thanksgiving Day
• Christmas Day

Bottom line: Labor Day is a federal U.S. holiday that falls on the 1st Monday in September and is considered the unofficial end of summer.

The post Labor Day: Learn its history and traditions first appeared on EarthSky.

• Finding microbial life beyond Earth would be more than a scientific breakthrough. It has the potential to change how humanity thinks about itself.
• Experts see three possible responses: nations could cooperate on research and regulation, or they could compete for scientific and economic advantages, or they could isolate themselves because of biosecurity concerns.
• Policymakers can prepare now by using scenario planning to consider these possibilities, because the discovery of extraterrestrial life has the potential to bring both unprecedented cooperation and new forms of rivalry.

By Margaret E. Kosal, Georgia Institute of Technology; Dayana Alagirova, Georgia Institute of Technology, and Karryl Kim Sagun Trajano, Nanyang Technological University

If we find life beyond Earth, how will nations respond?

Microbes from space have fueled the plots of science fiction mainstays like Project Hail Mary and The Andromeda Strain. But with more space missions launching each year, finding extraterrestrial life in a microbial form is becoming more plausible. What will the response be back here on Earth if – or when – scientists discover extraterrestrial microbes? Will the international policy and security communities be prepared for the fallout?

When you hear about extraterrestrial life, your mind may go to intelligent life, like the kind present in a lot of Hollywood science fiction. But even the confirmation of microbial life that originated somewhere other than on Earth – which is much more likely – would be a paradigm-shifting event. Thinking about what these consequences might look like early on can help nations and the international community prepare.

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Preparing for the possibility of life beyond Earth

Our team is interested in this question. We’re made up of a full professor of international affairs, who earned a Ph.D. in chemistry, and whose expertise is on how emerging science and technologies could affect global conflict and cooperation, as well as an emerging scholar in space policy and security and an expert on social and political implications of frontier technologies, such as AI, space, quantum and energy sources.

Multiple Mars landers have identified large amounts of frozen and liquid water, essential for life, on the red planet. Samples retrieved by Japan’s Hayabusa2 spacecraft from a near-Earth asteroid revealed the presence of uracil, part of RNA, which is a building block of life. Uncrewed space probes like NASA’s Europa Clipper and the European Space Agency’s Jupiter Icy Moons Explorer are on their way to conduct detailed reconnaissance of the planet’s moons and to investigate whether they have conditions suitable for life.

Along with data from the James Webb Space Telescope and future missions targeting Saturn’s icy moon Enceladus, the likelihood of discovering extraterrestrial microbial life has increased substantially.

A governance challenge

The discovery of microbial life would expose significant gaps in international governance related to space.

While there are some existing international agreements, including the Outer Space Treaty, that provide space law guidelines, these are ill-equipped to address the complexities posed by extraterrestrial biology.

The Outer Space Treaty, established in 1967, dictates that countries should use outer space peacefully. It also states that no single nation may claim ownership or exert sovereignty over parts of outer space or celestial bodies such as the moon.

However, it doesn’t have much to say about who can own extraterrestrial organisms or what to do about biosecurity risks. It doesn’t have direction for who can use, preserve or destroy living things, such as bacteria or fungi, that may be discovered in space.

Historical analogies and future pathways

While people have yet to discover extraterrestrial life of any kind, there are some major geopolitical events that can help researchers understand what the consequences might look like.

While the space race of the 1950s and ’60s led to exploration of the moon, it was driven by a Cold War power struggle between two nations back on Earth. Instead of coming together to explore space, both countries experienced a renewed sense of nationalism. They used the new discoveries that came from the space race to invest in their military capabilities.

On the other hand, researchers can look at how states respond to asteroid threats. Since an asteroid could pose a truly existential threat from space, preventing the worst-case scenario requires cooperation and thinking ahead.

Astronomers have built a global, collaborative network to monitor for and sound the alarm about any potential threats. This network has shown that nations can put aside terrestrial rivalries to work together if they perceive something from space as a truly existential threat.

The International Space Station is another example showing how nations that are competing great powers on Earth work together to cooperate in space. Countries have collaborated to solve issues on the International Space Station that have specific, short-term and clearly identified goals.

These examples show a range of possible reactions to the discovery of space microbes. The situation could renew space races between competing countries and lead to militarization, or it could create unprecedented cooperation.

Read on for the three main possible outcomes we’ve identified to the discovery of microbial extraterrestrial life.

Cooperation

First, there’s a cooperative outcome, reminiscent of the asteroid threat network or the International Space Station. Here, nations collaborate to regulate research, share data, protect the planet or advance specific interests they share.

This pathway isn’t inherently benign or malignant. It could entail expanding the roles of international organizations or creating new legal instruments.

Competition

Second there’s a competitive outcome, characterized by strategic rivalry between countries. Like in the space race, nations could fight to be technologically superior. They might try to monopolize access to the extraterrestrial microbes or to leverage biological discoveries from the microbes for their own economic or military advantage.

Scientific breakthroughs derived from extraterrestrial organisms could lead to innovations in medicine, agriculture, energy and beyond. However, the organisms could also be weaponized, intentionally or otherwise, which would amplify biosecurity risks. In this sense, the discovery of microbial life could create a new form of technological competition, one that merges space exploration with biological research and development.

The increasing role of private companies, such as SpaceX, complicates this dynamic. These companies receive contracts from the government, blurring the lines between commercial civilian and strategic activities.

For example, around 60% of all satellites currently orbiting the Earth belong to SpaceX’s Starlink subsidiary. The company can – and has – chosen to block access selectively, in alignment with its political priorities. When commercial interests and national priorities diverge, who has access versus who is denied access can be uncertain.

Research around biopiracy may come into play. Biopiracy is a term that applies to two primary issues: the patenting of indigenous knowledge or the patenting of natural resources, such as microbes, for profit. The Budapest Treaty prohibits claiming ownership of a naturally occurring microbe on Earth, but there’s no equivalent for microbes in space.

Isolation

Third is an isolationist outcome, in which states could sever their involvement in international cooperation due to biosecurity concerns or political distrust. The potential for unknown biological risks, however minimal, could trigger precautionary restrictions on data sharing, which limits international collaboration.

Countries may lose or gain allies as they grapple with whether the microbe could cause harm to humans or the environment, or be developed into a biological weapon.

Emerging technologies will also shape these outcomes. Artificial intelligence and machine learning are already integral to scientific research. Scientists use them to process astronomical data and identify potential biosignatures. Nanotechnology and advances in the life sciences and engineering could allow researchers to study, modify or exploit extraterrestrial microbes, if they’re given access to them.

Countries will have to prepare not only for the scientific implications of discovery but also for its societal and political reverberations. The politicization of scientific discoveries from the microbes could complicate or change how countries respond domestically and at the international scale. Misinformation about the microbes could shape policy and public response.

Preparing for the unprecedented

The discovery of extraterrestrial microbial life would not merely mark a scientific milestone. It would be a geopolitical event.

Rather than attempting to predict a singular outcome, policymakers could adopt scenario-based planning approaches in the meantime to anticipate and prepare for a range of possibilities. In these approaches, participants explore multiple futures through structured activities similar to professional or military wargaming or path games, in which they explore multiple outcomes systematically to test strategies, to plan and to analyze potential outcomes under realistic uncertainty.

In our view, the question is not whether humanity will discover life beyond Earth, but whether it is prepared for the consequences when it does.

Margaret E. Kosal, Georgia Institute of Technology; Dayana Alagirova, Georgia Institute of Technology, and Karryl Kim Sagun Trajano, Nanyang Technological University

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

Bottom line: If we ever find life beyond Earth, how will the nations of the world respond? A group of experts say there are three possibilities: cooperation, competition and isolation.

The post If we find life beyond Earth, how will nations respond? first appeared on EarthSky.

Sun news September 06 (UTC): Blast sends radiation storm and more our way

Today’s top story: Solar activity climbed to moderate levels over the past day, and from an unlikely source. Plage Region 4520. That region is a once-prominent sunspot group that had decayed to a featureless plage—a hot, bright region near a sunspot (or in this case a former sunspot). This one is near the sun’s southwest limb. It fired off an M1.0 flare at 15:04 UTC on September 5. And it launched energetic protons toward Earth, briefly crossing the S1 (minor) solar radiation storm threshold. The proton flux above 100 MeV also spiked. That’s relatively uncommon, and it highlights the event’s eruptive power despite its modest flare class. A coronal mass ejection (CME) accompanied the flare. Modeling indicates it won’t strike us, but instead will sweep ahead of Earth in orbit. No direct hit is expected. AR4524 unleashed a fast C8.5 flare and an associated CME with an estimated speed of 1,110 km/s. That eruption, combined with a slower CME from earlier in the day, should reach Earth around September 7 and 8. Together they could drive geomagnetic storms and enhance auroral displays. G1-G3 storms are possible! Meanwhile, a coronal hole high-speed stream and a solar sector boundary crossing are converging on the same timeframe. In short, the stage is set for a busy auroral period ahead.

Past 24 hours on the sun

(11 UTC September 05 – 11 UTC September 06)

Flare activity: Solar activity increased to moderate levels. Observers recorded one M-class and four C-class flares during the reporting period.

• Strongest flare: An M1.0 from Plage Region 4520 (S12W68) at 15:04 UTC on September 5. It triggered an R1 (minor) radio blackout affecting high-frequency communications across the northeastern part of South America. The flare also produced S1 (minor) solar radiation storm proton enhancements at both the 10 MeV and 100 MeV thresholds.
• Other notable flares: A C8.5 from AR4524 at 17:32 UTC on September 5. A C6.5 from AR4524 at 10:24 UTC on September 5. A C4.0 from AR4525 at 15:31 UTC on September 5. And a C1.5 from AR4525 at 11:56 UTC on September 5.
• Lead flare producer: AR4524 topped the list, firing the two strongest C-class events (C8.5 and C6.5). It also produced Type II and Type IV radio emissions with the earlier C6.7 event on September 4.

Sunspot regions: The Earth-facing solar disk displayed at least nine active regions, including three unnumbered spots near the east limb. Most stayed magnetically simple and relatively small.

Blasts from the sun? Observers spotted several coronal mass ejections (CMEs) during the period. Two carry modeled Earth-impact predictions. The others should miss.

Past 24 hours in space weather

Solar wind: Solar wind parameters stayed at nominal, slow-wind levels throughout the reporting period. Speeds averaged around 350 km/s, with a brief peak to 372 km/s at 16:18 UTC on September 5. A high-speed stream from the equatorial coronal hole should soon influence conditions.

Bt, Bz and magnetic coupling: The interplanetary magnetic field (IMF) total strength was low. Meanwhile, the Bz component made weak southward dips but spent much of the period oscillating. It favored a northward orientation during the first half and leaned southward during the second half.

Earth’s magnetic field: Earth’s magnetic field held at quiet to isolated unsettled levels, with the Kp index remaining at 0 to 2 for most of the period. Conditions crossed no G-scale geomagnetic storm thresholds. They reflected the benign, slow solar wind environment, since the weak and variable Bz proved insufficient to drive significant geomagnetic coupling. The estimated Ap index for September 4 was just 3, firmly in quiet territory.

Energetic particles: The greater than 10 MeV proton flux began rising at 15:30 UTC on September 5. It exceeded the S1 (minor) solar radiation storm threshold at 16:45 UTC. Levels stayed elevated near the threshold by the end of the reporting period. Meanwhile, the greater than 100 MeV proton flux briefly exceeded its threshold at 15:50 UTC and decayed below the threshold by 16:16 UTC.

What’s ahead? Sun–Earth forecast

Flare activity forecast: Forecasters expect solar activity to remain at low levels, with occasional C-class flares through September 8. A slight chance (20%) remains for M-class flares (R1–R2), primarily from AR4524, which stays the most magnetically complex region on the disk despite losing some trailing spots. There is a slight chance (1%) of an isolated X-class flare, most likely from the new regions emerging on the east limb if they develop further complexity. Meanwhile, the greater than 10 MeV proton flux should stay near or above the S1 threshold through early September 6, then slowly decay to background through September 7 and 8.

Geomagnetic activity forecast:

• September 6: Expect mostly quiet conditions (Kp 0-2) through most of the day. A very weak, slow CME from September 2 may deliver a glancing blow around 16:00 UTC. However, confidence is low, and any impact would be minimal (Kp 2 to 3). Isolated unsettled conditions (Kp 3) are likely by late in the day as a solar sector boundary crossing begins and the leading edge of the coronal hole high-speed stream approaches. Aurora is unlikely for mid-latitude observers.
• September 7: Expect unsettled to periodic active conditions (Kp 3-4) as the SSBC and coronal hole stream strengthen. Then, by late September 7, the faster CME from the C8.5 flare (1,110 km/s) may arrive around 23:21 UTC. If the impact geometry proves favorable, Kp could reach 5 to 7. That would produce G1 (minor) to G2 (moderate) geomagnetic storm conditions, with a chance of isolated G3 (strong) intervals. At Kp 5 to 6, aurora may appear over Seattle, Minneapolis, Edinburgh, Toronto, and northern England. At Kp 7, displays could reach as far south as New York, London, and northern France.
• September 8: The second CME, from the C6.5 flare (873 km/s), should arrive around 02:52 UTC. It may combine with lingering effects from the first. Kp estimates of 4 to 6 suggest continued G1 to G2 storm potential, particularly during the first half of the day. The filament eruption CME may also add to the disturbance. Conditions should gradually wane through the second half of September 8 as the combined influences subside. Aurora watchers across northern Europe, Canada, and the northern United States should stay alert. If conditions align, this could be a multi-night event.

Sun news September 5: Bam bam! The sun issues a 1-2 punch

The sun surprised us with two blasts in sequence, like a 1-2 punch, with one blast from the sun’s northeast horizon and one from the southeast. The first erupted near sunspot region AR4524. It started at around 19 UTC on September 4, and it came with a C6.7 flare. The second blast, in the southeast, started at around 20:56 UTC on September 4, almost right on the heels of the first. No visible flare accompanied this one, meaning it must have erupted just behind the sun’s limb, or edge, from an active region whose arrival on the Earth-facing disk is imminent. Both prominences hurled solar plasma into space. But initial analyses suggest the resulting coronal mass ejections (CMEs) are not Earth-directed. Stay tuned!

Past 24 hours on the sun

(11 UTC September 4 – 11 UTC September 5)

Flare activity: Solar activity returned to low levels, with only C-class and B-class events. Over the past day, our star sparked a total of seven flares: 5 C flares and 2 B flares.

• Strongest flare: A C7.1 from AR4525 at 11:29 UTC on September 4.
• Other notable C flares: A C6.7 at 19:30 UTC on September 4 from AR4524. A C2.1 at 13:05 UTC on September 4 from AR4527. And a C1.3 at 15:27 UTC on September 4 from AR4518.
• Lead flare producer: Two sunspot regions ended tied at the top of the list, firing two flares each: AR4525 and AR4526.

Sunspot regions: Currently, the Earth-facing solar disk displays 4 numbered sunspot regions. One is a newcomer on the northeast limb, labeled AR4527.

• AR4521 (alpha): This region stayed stable and quiet throughout the period. It produced no notable flares.
• AR4523 (alpha): This region showed some growth over the past 24 hours. However, it produced no flares this time.
• AR4524 (beta): This region showed some growth. It also produced a C flare during this period.
• AR4527 (alpha): This newcomer received its number during the period. It needs to rotate further into view for a better analysis. Even so, it has already produced a C flare.

Blasts from the sun? Observers spotted multiple coronal mass ejections (CMEs) yesterday and today. The fiery prominences we saw should not hit Earth directly. But, given their size, they might carry a component that might reach us. Any impact would be minor at best. Modeling and analysis of these events continue.

Past 24 hours in space weather

Solar wind: Solar wind parameters reflected mostly normal, slow-wind conditions throughout the period. Meanwhile, an equatorial coronal hole has reached a geoeffective position at the center of the Earth-viewed solar disk. Its high-speed stream may begin impacting our magnetic field in the coming days.

Bt, Bz and magnetic coupling: The interplanetary magnetic field (IMF) total strength (Bt) ran slightly elevated, at moderate levels. Meanwhile, the Bz pointed north early in the period. Then, at 22:30 UTC on September 4, it shifted southward and held that direction for the rest of the period. That kept conditions favorable for aurora production. At the time of this writing, the Bz still points south.

Earth’s magnetic field: Earth’s magnetic field stayed quiet-to-unsettled throughout the period, with the Kp index at 0 to 3. No geomagnetic storm conditions occurred. As of this writing, the Kp index sits just below level 3.

Sun news September 4: More action from returning sunspot region

An exciting sunspot region emerging from the sun’s northeast horizon continued making its presence felt over the past day. Numbered AR4524, this region fired off an M1.2 flare at 7:45 UTC this morning, the strongest event of the 24-hour period. This same region had earlier produced a C7.9 flare with a powerful eruption of sun-stuff, which is heading well away from Earth. This sunspot group appears to have already passed across the face of the sun in mid-August, before rotating around our star’s far side. Now, it’s returning over the eastern horizon. On its last passage, it had an impressive magnetic complexity. As it rotates back into full view within the next day, we’ll be able to see how much potential it’s held on to.

Past 24 hours on the sun

(11 UTC September 3 – 11 UTC September 4)

Flare activity: Solar activity reached moderate levels. Observers logged 11 flares: 1 M-class and 10 C-class events.

• Strongest flare: An M1.2 from AR4524 at 7:45 UTC on September 4. It triggered an R1 (minor) radio blackout, briefly affecting high-frequency communications over the Arabian Sea.
• Other notable flares from AR4524: C7.9 at 16:13 UTC on September 3, C2.0 at 17:00 UTC on September 3, C1.3 at 06:08 UTC on September 4.
• Lead flare producer: AR4523 topped the list, firing 6 C-class flares.

Sunspot regions: The Earth-facing solar disk displayed 3 numbered sunspot regions. A fourth should rotate into view imminently from beyond the northeast limb.

• AR4521 (alpha): This region stayed stable and quiet throughout the period. It produced no notable flares.
• AR4523 (beta): This region grew over the past 24 hours. It was also the most prolific flare producer, generating multiple C-class events up to C6.9. So it bears watching as it continues to develop.
• AR4524 (alpha): This returning region currently sits near the east limb. It produced the period’s strongest flare, the M1.2, plus the notable C7.9 event. It was magnetically complex during its previous disk transit in mid-August. So it may regain that complexity as it rotates further into view, raising the prospect of stronger flaring.
• In addition, bursts of sun-stuff from beyond the eastern limb during the period confirms that a significant active region is about to rotate onto the visible disk, likely within the next 24 hours.

Blasts from the sun? Observers spotted multiple coronal mass ejections (CMEs) during the period. However, none should directly hit Earth. Two earlier CMEs from September 2 carry the potential to reach us, but impacts would be minor at best.

Past 24 hours in space weather

Solar wind: Solar wind parameters reflected mostly normal, slow-wind conditions throughout the period. Meanwhile, an equatorial coronal hole has reached the center of the Earth-viewed sun. Its high-speed stream may begin impacting our magnetic field in the coming days.

Bt, Bz and magnetic coupling: The interplanetary magnetic field (IMF) total strength (Bt) was slightly elevated. Meanwhile, the Bz component fluctuated between north and south. That kept Earth’s magnetic shield largely intact and conditions unfavorable for aurora production.

Earth’s magnetic field: Earth’s magnetic field stayed quiet throughout the period, with the Kp index remaining at 1 to 2. No geomagnetic storm conditions occurred.

Sun news September 3: Big flare from newcomer sunspot

Bam! A newcomer sunspot region sparked an impressive M3.0 flare around 19:20 UTC last night. This region is just showing its nose on the northeast solar horizon. It was unnumbered at the moment of the flare, but it’s now been labeled AR4524. This region started showing off its potential with a fiery prominence we reported a couple of days ago. Now, it’s the region to watch. The M3 flare did hurl plasma into space, but this coronal mass ejection (CME) doesn’t appear to be coming our way. But once AR4524 rotates toward the center of the solar disk, a flare like this could sent material toward Earth. Stay tuned.

Past 24 hours on the sun

(11 UTC September 2 – 11 UTC September 3)

Flare activity: Solar activity jumped to moderate levels, thanks to the M-class flare. Over the past day, our sun produced a total of 12 flares: the M3, four C-class (common) flares, and seven B-class (weak) flares.

• Strongest flare: An M3.0 from the incoming northeast region, now numbered AR4524, at 19:20 UTC on September 2.
• Lead flare producer: That same newcomer, AR4524, reached the top of the list with eight flares this period: the M flare, all four C flares of the period, plus three B flares.

Sunspot regions: From Earth, we see four numbered sunspot regions on the solar disk. There is a newcomer on the solar disk: AR4524.

• AR4520 (beta): This region’s magnetic configuration stayed stable. It produced only one B flare during the period.
• AR4521 (alpha): This region kept relatively stable and produced no flares.
• AR4523 (beta): This region produced three B flares during the period.
• AR4524 (alpha): This region sits close to the northeast horizon. It rapidly became the lead flare producer and sparked a strong M3.0 flare. This is the guy to keep watching in the coming days.

Blasts from the sun? The M3.0 event from AR4524 clearly hurled plasma into space. The bulk of that coronal mass ejection (CME) lies off the sun-Earth line. Nevertheless, modeling and analysis continue to determine whether any component is coming our way. Separately, a filament eruption at 9:08 UTC on September 2 produced a CME. Initial analysis suggests a glancing blow is possible on September 7.

Past 24 hours in space weather

Solar wind: Solar wind speeds continued at low levels. The influence of the coronal hole high-speed stream has vanished. No significant space weather to report this time.

Bt, Bz and magnetic coupling: The interplanetary magnetic field started our observation period at weak levels. Then, at 7 UTC this morning, it spiked briefly to moderate levels before dropping back to weak. Meanwhile, the Bz component kept fluctuating between south and north orientations throughout the period, with north dominating. As always, prolonged southward Bz periods favor auroras by letting solar wind energy couple more efficiently with Earth’s magnetosphere. At the time of this writing, the Bz still points northward.

Earth’s magnetic field: Earth’s magnetic field showed quiet levels during the period, with the Kp index at 1 to 2. At the time of this writing, the Kp index sits just at level 1.

Sun news September 2: New update for Solar cycle 25

The NOAA Space Weather Prediction Center just released its solar cycle progression results for August 2026. The monthly sunspot number slipped slightly to 76, compared to 78.1 in July 2026. Meanwhile, August 2024 still stands as the peak of Solar Cycle 25. Since then, the cycle has been in its declining phase. Even so, as the past two weeks showed, a declining sun can still deliver plenty of action.

Past 24 hours on the sun

(11 UTC September 1 – 11 UTC September 2)

Flare activity: Solar activity stayed at low levels, with only faint C-class and B-class flares. Over the past day, our sun produced a total of seven flares: three C-class (common) flares plus another four B-class (weak) flares.

• Strongest flare: A C5.7 from an incoming, as-yet-unnumbered region in the northeast at 21:10 UTC on September 1.
• Lead flare producer: That same northeast newcomer, still awaiting its number, topped today’s list. It produced four flares (two Cs and two Bs) including the strongest of the period.

Sunspot regions: The solar disk, as we see it from Earth, shows five numbered sunspot regions today.

• AR4518 (alpha): This region has decayed to a simple alpha magnetic configuration. Just yesterday it was the only region showing growth. Now it produced no flares.
• AR4520 (beta): This region stayed stable, though it showed signs of decay. It produced only one B flare during this period.
• AR4521 (alpha): This region kept relatively stable.
• AR4522 (beta): This region is in decay and produced no flares.
• AR4523 (alpha): This region stayed stable with no flare production.

Blasts from the sun? Forecasters reported no Earth-directed coronal mass ejections (CMEs) in the last 24 hours.

Past 24 hours in space weather

Solar wind: Solar wind speeds continued slowly decreasing, from moderate-low to low levels. The influence of the coronal hole high-speed stream has almost vanished, as space weather conditions drop back to background levels.

Bt, Bz and magnetic coupling: The interplanetary magnetic field continued at weak levels. Meanwhile, the Bz component fluctuated between south and north orientations throughout the period. Neither direction dominated, since the Bz held each orientation only briefly. As always, prolonged southward Bz periods favor auroras by letting solar wind energy couple more efficiently with Earth’s magnetosphere. At the time of this writing, the Bz has shifted southward.

Earth’s magnetic field: Earth’s magnetic field held at quiet-to-unsettled levels during the period, with the Kp index at 1 to 3. Any visible aurora displays would have stayed confined to high latitudes such as northern Scandinavia, Iceland, and northern Canada. At the time of this writing, the Kp index sits just at level 2.

Sun news September 1: Sun-observing spacecraft sees a solar eclipse

The solar observations from NOAA’s GOES-19 spacecraft were interrupted over the past day. That’s because Earth passed in front of our star from the satellite’s perspective. It’s our planet you can see taking a bite out of the solar disk! These eclipses occur twice a year, around the equinoxes.

Past 24 hours on the sun

(11 UTC August 31 – 11 UTC September 1)

Flare activity: Solar activity continued at low levels, though flare production increased sharply. During the past day, our sun produced a total of 15 flares, compared to just 2 yesterday. This period’s tally: 5 C-class (common) flares plus another 10 B-class (weak) flares.

• Strongest flare: A C2.6 from AR4520 at 15:16 UTC on August 31.
• Lead flare producer: A tie at the top of the list. AR4517 and AR4520 each produced 5 flares, sharing the honor.

Sunspot regions: Currently, the Earth-facing solar disk displays five numbered sunspot regions, all relatively small and magnetically simple. Three newcomers received numbers during the period: AR4521, AR4522, and AR4523.

• AR4518 (beta): Stable, no flares produced during this period.
• AR4513 (beta): This region is now out of view, having rotated to the far side of our sun.
• AR4520 (beta): This region gained additional spots. It also produced the strongest flare of the period, a C2.6.
• AR4521 (alpha), AR4522 (beta), and AR4523 (alpha): These regions gained spots during the period but otherwise remained stable. Only AR4523 produced flares, contributing 2 C flares.

Blasts from the sun? Forecasters reported no Earth-directed coronal mass ejections (CMEs) in the last 24 hours.

Past 24 hours in space weather

Solar wind: Solar wind speeds slowly decreased from moderate to moderate-low levels, as the influence of a coronal hole high-speed stream began to wane.

Bt, Bz and magnetic coupling: The interplanetary magnetic field averaged at weak levels. Meanwhile, the Bz component fluctuated between south and north orientations. Even so, several sustained southward intervals dominated. A southward Bz favors auroras by letting solar wind energy couple more efficiently with Earth’s magnetosphere.

Earth’s magnetic field: Earth’s magnetic field showed quiet levels during the period, with the Kp index at 1 to 2. No significant aurora enhancements were expected at middle latitudes. Any visible displays would have stayed confined to high latitudes such as northern Scandinavia, Iceland, and northern Canada.

Sun news August 31: Fast coronal hole winds now easing

Earth’s magnetic field was stirred to active levels early in the past day as a stream of high-speed solar wind from a coronal hole continued to wash over our planet. However, that disturbance is now fading. Meanwhile, a large filament eruption in the sun’s northeast added a touch of drama. Forecasters are still analyzing coronagraph imagery to determine whether any of that material is headed our way.

Past 24 hours on the sun

(11 UTC August 30 – 11 UTC August 31)

Flare activity: Solar activity remained at low levels. Observers logged only 2 C-class (common) flares and several B-class (weak) events during the period.

• Strongest flare: A C2.2 from AR4513 at 16:41 UTC on August 30.
• Lead flare producer: AR4513 topped the list, responsible for the C2.2 plus a B9.8 event at 12:48 UTC on August 30.

Sunspot regions: The Earth-facing solar disk displayed six numbered sunspot regions, all relatively small and magnetically simple.

• AR4518 (beta): This was the only region to show growth during the period. That makes it the most noteworthy spot group on the disk, despite its modest size.
• AR4517 (beta): This region is approaching the west limb. It should rotate out of view in the coming hours.
• AR4513 (beta): This region is also nearing the west limb. It produced the period’s strongest flare, the C2.2.
• The remaining active regions carried alpha or beta magnetic configurations. All were stable or decaying, and none produced significant flaring.

Blasts from the sun? No Earth-directed coronal mass ejections (CMEs) have been confirmed at this time. Observers spotted a large filament eruption in the northeast beginning around 6 to 7 UTC on August 30. Forecasters now await further coronagraph data to determine whether any associated CME carries an Earth-directed component.

Past 24 hours in space weather

Solar wind: Solar wind speeds stayed modestly enhanced under the continued influence of a coronal hole high-speed stream.

Bt, Bz and magnetic coupling: The interplanery magnetic field total strength peaked early in the period, then eased by the end. Meanwhile, the Bz component fluctuated erratically. Several sustained southward intervals drove the active geomagnetic conditions. As always, a southward Bz favors auroras by letting solar wind energy couple more efficiently with Earth’s magnetosphere. Conditions should gradually ease as the stream’s influence wanes.

Earth’s magnetic field: Earth’s magnetic field ranged from quiet to active levels during the period, driven by the coronal hole stream. The Kp index reached 4, placing conditions at the active threshold without crossing into G1 (minor) geomagnetic storm levels. The active intervals clustered during stretches of sustained southward Bz, while quieter spells arrived when the Bz turned northward. No significant aurora enhancement was expected at middle latitudes. Any visible displays would have stayed confined to high latitudes such as northern Scandinavia, Iceland and northern Canada.

The sun in recent days

Earlier sun images

Sun images from our community

More sun images from our community

We sometimes feature sun images obtained using hydrogen-alpha filters. Read why.

Bottom line: Sun news September 6, 2026: An M1.0 flare sparked an S1 radiation storm. Two fast CMEs from AR4524 race our way, with G1-G3 storms possible Sept 7-8.

Submit your photos here.

View community photos here.

The post Sun news: Blast sends radiation storm and more our way first appeared on EarthSky.

Join EarthSky’s Marcy Curran for your skywatching best bets for this week. Don’t miss the lovely waning crescent moon cozying up to the bright planet Jupiter on the morning of September 8. It’ll be a beautiful sight before dawn. See what’s in store in the night sky this week. Watch here or on YouTube.

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view – and time – from your location, try Stellarium Online.

Will Triggs explains: Why Jupiter has returned

If you go outside and look just as dawn is breaking, you should be able to see bright Jupiter near the sunrise point. In this video, EarthSky’s Will Triggs explains why Jupiter is returning now, and what to expect from our sky’s 2nd-brightest planet (after Venus) in the months ahead. Watch in the player above or on YouTube.

All-sky view of morning planets

The big picture: September’s 5 best sky sights

September 2026 has an especially beautiful night sky! In this livestream with host Deborah Byrd, we’ll look at 5 things you won’t want to miss. So join us! Watch in the player above, or on YouTube.

At this time of year, watch for the zodiacal light

September 11: New moon

Want more? Here are 4 keys to understanding the moon’s phases.

September 13 and 14 evenings: Moon visits Venus

Around September 15: Venus brightest and near moon

Read more: Massive ruby red Antares is the Scorpion’s Heart

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view – and time – from your location, try Stellarium Online.

September 16 and 17 evenings: Moon near Antares

September 18: 1st quarter moon

Want more? Here are 4 keys to understanding the moon’s phases.

September 18 and 19 evenings: Moon near Teapot

Read more: Teapot of Sagittarius points to Milky Way center

Late September evening planets: Northern Hemisphere view

September 23: September equinox

Full Harvest Moon September 26

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view – and time – from your location, try Stellarium Online.

September 28 evening: Moon near Pleiades

September 29 and 30 evenings: Moon near Pleiades

September evening planets

September morning planets

September stars

If you’re out stargazing on any September evening, look for these stars and constellations overhead in the evening sky.

Our charts are mostly set for the northern half of Earth. To see a precise view – and time – from your location, try Stellarium Online.

Have fun exploring the sky!

New to stargazing? Read more: Planisphere: Your friend to find stars and constellations

Sky dome map for visible planets and night sky

Read more: Guy Ottewell explains sky dome maps

Heliocentric solar system visible planets and more

Read more: Guy Ottewell explains heliocentric charts.

Some resources to enjoy

For more videos of great night sky events, visit EarthSky’s YouTube page.

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Visit EarthSky’s Best Places to Stargaze to find a dark-sky location near you.

Post your own night sky photos at EarthSky Community Photos.

Visit Stellarium-Web.org for precise views from your location.

Bottom line: Visible planets and night sky guide: Watch a video with this week’s best sky sights. And look for the thin crescent moon near Jupiter on Tuesday morning.

The post Visible planets and night sky guide for September first appeared on EarthSky.

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Octans and Apus

Octans the Octant and Apus the Bird of Paradise circle the south celestial pole. If you want to see them, you’ll have to be in the Southern Hemisphere. In fact, the south celestial pole lies inside the constellation boundary for Octans.

Both of these constellations are south circumpolar constellations. Of course, the north has circumpolar constellations too. Constellations such as Ursa Minor, Ursa Major and Draco can be seen any night of the year from the Northern Hemisphere. Octans and Apus are two constellations that Southern Hemisphere observers can view on any clear evening.

Octans the Octant

And Octans is a key constellation for another reason. When we look in its direction in space, we are looking toward Earth’s south celestial pole. Polaris is the famous star marking the location of the north celestial pole. But the Southern Hemisphere has no bright star near its celestial pole. That is why you might hear astronomers say there’s no pole star for the Southern Hemisphere sky.

There is an extremely dim galaxy that’s nearly at the location of the south celestial pole. And that galaxy has the fitting name of Polarissima Australis. It shines much too dimly to be viewed without optical aid, at magnitude 13.5.

The brightest star in Octans is only moderately bright at +3.7 magnitude. It is Nu Octantis, a double star, located some 69 light-years away. The star is home to a confirmed super-Jovian exoplanet. So far, no other planets have been found in the Nu Octantis system.

Apus the Bird of Paradise

Then, next to Octans, is Apus the Bird of Paradise. It’s small and ranked 67th in size out of the 88 constellations. It lies between Octans and Triangulum Australe the Southern Triangle. The stars in Apus are quite dim. The brightest member of the constellation is Alpha Apodis at magnitude 3.83. Alpha Apodis lies about 430 light-years from Earth. Slightly fainter is Gamma Apodis at magnitude 3.86 and 150 light-years distant. This star is a strong source of X-rays.

Bottom line: Octans and Apus are two constellations that you have to be in the Southern Hemisphere to see. Plus, Octans is home to the south celestial pole.

The post Octans and Apus circle the south celestial pole first appeared on EarthSky.

• Mars is a cold world, with ice caps and lots of ice below the surface.
• But new research has discovered strange excess heat deep below the surface of southern hemisphere.
• Explanations range from a giant impact releasing thermal energy to thick geological features trapping heat.

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Mars’ southern hemisphere is unexpectedly hot deep below the surface

Mars is a very cold planet on the surface. Like Earth, it gradually gets warmer the deeper you go into its interior. But now, researchers at Caltech in California have found an unusual anomaly. They said on August 26, 2026, that there’s a huge excess of heat deep below Mars’ surface in the southern hemisphere. In fact, the region is about 200-400 degrees Celsius (290-750 degrees Fahrenheit) hotter than expected.

The heat anomaly seems to mirror the north-south asymmetry of Mars. The planet’s northern hemisphere is mostly flat lowlands, while the southern hemisphere is covered by craters and mountains. Because of this, Mars sometimes is referred to as as being “two-faced.” Now it seems that rather than being simply a surface feature, that characteristic runs deep into the inside of the planet as well.

The researchers published their peer-reviewed findings in Nature on August 26, 2026.

Measuring spacecraft velocities

How did the researchers discover this anomaly? Caltech alumnus Alexander Berne led the new study. Berne and his team used data collected over decades from three different Mars missions: Mars Global Surveyor, Mars Odyssey and Mars Reconnaissance Orbiter. The team measured tiny variations in the spacecrafts’ velocities and then used them to reconstruct the gravitational field around Mars.

Using a technique called tidal tomography, or planetary tomography, the researchers measured how those gravitational signatures vary over time. This enabled the team to create a model of the planet’s interior. As Berne explained:

Scientists usually assume that the interiors of planetary bodies are generally spherically symmetric, but this is not necessarily true. As we get more gravity data, we can determine the three-dimensional intricacies of a planet’s interior structure. These inferences in turn give us a blueprint for designing future missions and scientific exploration of these worlds. Understanding the interior structure of planetary bodies helps us unravel the processes that shaped their formation and evolution.

An unbalanced interior

Like Earth, Mars isn’t perfectly spherical. The northern lowlands are mostly quite flat, while the southern hemisphere has mountains and many deep craters. And this is where the thermal anomaly comes in. The interior of the southern hemisphere is much hotter than the north, by about 200-400 degrees Celsius (290-750 degrees Fahrenheit). At those temperatures, the rock is partially molten.

What could explain Mars’ southern hemisphere anomaly?

The researchers have proposed a few hypotheses to explain the anomaly. One is a giant impact that released heat from the northern hemisphere.

Another possibility is spontaneous convection – the movement of heat through fluids – in the southern mantle.

Finally, it could be caused by thick geological features in the southern hemisphere that trap excess heat from escaping.

The findings also have implications for the geological history of Mars and its habitability billions of years ago. Co-author Amirhossein Bagheri, a postdoctoral scholar at Caltech, said:

The dichotomy that we see between north and south is important to understand because it gives information about processes that may have influenced the hydrology of Mars, including the formation of basins that may have held water.

Bottom line: A new study from Caltech shows that Mars’ southern hemisphere is much hotter than expected deep below the surface. Why is that?

Source: Tidal tomography reveals a thermal anomaly beneath Mars’s crustal dichotomy

Via Caltech

Read more: Mars’ interior might contain remnants of baby planets

Read more: Marsquakes might explain Mars’ north-south hemisphere differences

The post Mars’ southern hemisphere is unusually hot deep underground first appeared on EarthSky.

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Cassiopeia the Queen in autumn

Any late summer evening and throughout northern autumn, Cassiopeia the Queen will be ascending in the northeast after nightfall. The shape of this constellation makes Cassiopeia’s stars very noticeable. Cassiopeia looks like the letter W (or M).

Look for the Queen at nightfall in September, and notice how she gets higher in the northeast with each day as northern autumn unfolds.

For those at the latitudes of the northern U.S. and Canada, Cassiopeia is circumpolar. That means the constellation stays above the horizon all night, every night.

How to see Cassiopeia

Cassiopeia represents an ancient queen of Ethiopia. You still sometimes hear the old name for this constellation: Cassiopeia’s Chair. And some old star maps depict the queen sitting on the chair, marked by five stars.

These stars – the brightest ones in Cassiopeia – are Schedar, Caph, Gamma Cassiopeiae, Ruchbah and Segin.

Around the middle of the night during the autumn months, Cassiopeia swings above Polaris, the North Star.

Before dawn, look in the northwest.

Opposite the Big Dipper

Cassiopeia is opposite the Big Dipper in the northern sky.

That is, the two constellations lie on opposite sides of the pole star, Polaris.

So when Cassiopeia is high in the sky, as it is on evenings from about September through February, the Big Dipper is low in the sky. Every March, when the Dipper is ascending in the northeast, getting ready to appear prominent again in the evening sky, Cassiopeia is descending in the northwest.

A guide to deep-sky beauties

If you have a dark sky, look below Cassiopeia in the northeast on these autumn evenings for the Double Cluster in Perseus.

These are two open star clusters. Each consists of young stars still moving together from the primordial cloud of gas and dust that gave birth to them.

These two clusters are familiarly known to stargazers as H and Chi Persei.

Interestingly, their names are from two different alphabets, the Greek and the Roman. Stars have Greek letter names, but most star clusters don’t. Johann Bayer (1572-1625) gave Chi Persei its Greek letter name. Then, it’s said, he ran out of Greek letters. That’s when he used a Roman letter – the letter H – to name the other cluster.

Charts for Cassiopeia

Lore of Cassiopeia

In skylore and in Greek mythology, Cassiopeia is a beautiful and vain queen of Ethiopia. It’s said that she committed the sin of pride by boasting that both she and her daughter Andromeda were more beautiful than Nereids, or sea nymphs. Pridefulness, in mythology, is never wise.

Since her boast angered Poseidon, God of the Sea, he sent a sea monster (Cetus the Whale) to ravage the kingdom. So to pacify the monster, Cassiopeia’s daughter, Princess Andromeda, was left tied to a rock by the sea. Cetus was about to devour her when Perseus the Hero happened by on Pegasus, the Flying Horse.

Perseus rescued the princess, and all lived happily … and the gods were pleased, so all of these characters were elevated to the heavens as stars.

But – because of her vanity – Cassiopeia suffered an indignity. At some times of the night or year, this constellation has more the shape of the letter M, and you might imagine the Queen reclining on her starry throne.

At other times of year or night – as in the wee hours between midnight and dawn in February and March – Cassiopeia’s Chair dips below the celestial pole. And then this constellation appears to us on Earth more like the letter W. That’s when the Lady of the Chair, as astronomers sometimes call her, is said to hang on for dear life. If Cassiopeia the Queen lets go, she will drop from the sky into the ocean below, where the Nereids must still be waiting.

Cassiopeia by our EarthSky Community

Bottom line: Cassiopeia the Queen is an easy-to-find constellation. It has the shape of a W or M. Look for it in the north-northeast sky on September and October evenings.

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The post Cassiopeia the Queen ascends in September and October first appeared on EarthSky.

An international team led by Agustín Sánchez-Lavega has now confirmed the discovery of a Saturn south pole decagon: a 10-sided atmospheric figure swirling over Saturn’s south pole. NASA’s Hubble Space Telescope first captured faint, subtle hints of a 10-vertex polygonal shape in 2023. Ground-based amateur and professional astronomers noted an undulating band in 2024, which sharpened into a fully defined decagon structure in Hubble images taken in August–September 2025. The discovery team officially published in the journal Science Advances in September 2026.

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Here’s NASA’s original announcement of the Saturn decagon, published on September 2, 2026. Edits by Earthsky.

Saturn’s south pole decagon confirmed

Recent images with NASA’s Hubble Space Telescope have revealed a giant, evolving 10-sided atmospheric wave encircling Saturn’s south pole. This discovery marks the first time a large, regular-sided jet pattern has been observed in the planet’s southern hemisphere. The feature appears remarkably similar to Saturn’s famous hexagon at its northern pole. But it is also distinctly different, suggesting scientists may be witnessing a new atmospheric phenomenon develop on the iconic gas giant.

The results published Wednesday, September 2, 2026, in the journal Science Advances.

By piecing together several years of Hubble observations dating back to 2023, researchers found subtle hints of the structure beginning to emerge before it became a clearly defined pattern. Those observations were taken as part of Hubble’s Outer Planet Atmospheres Legacy (OPAL) program, which has photographed the outer planets annually for more than a decade.

Amy Simon, study co-author and OPAL principal investigator, NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said:

We’ve never seen anything quite like this in Saturn’s southern hemisphere. The northern hexagon has been there every time we’ve looked for more than 40 years. This feature is different – it appears to be strengthening, giving us the rare opportunity to watch a giant atmospheric pattern develop.

Saturn seasons made the discovery possible

The discovery was possible because Saturn’s changing seasons gradually brought the planet’s south pole back into view from Earth, where astronomers who collectively analyze images of Saturn from ground-based observatories first identified it.

Agustín Sánchez-Lavega, lead author of the new study, is a researcher at the University of the Basque Country in Spain. The university manages a website, called Planetary Virtual Observatory Laboratory, that accepts ground-based images of solar system planets contributed by observers all over the world. It was in those images, first in 2024, that Sánchez-Lavega and amateur astronomers Trevor Barry and Jean-Paul Oger noticed a subtle undulating band along the southern pole. Additional 2025 imagery taken from the ground hinted even more strongly toward this decagon structure.

That’s when the Hubble observations come into the picture. Hubble’s view from space offers unmatched image sharpness and spatial resolution over full rotations of Saturn, without smearing by Earth’s atmosphere. Sánchez-Lavega said:

Given Saturn’s symmetry in its north-south jet stream system, we have been searching for a counterpart to Saturn’s northern hexagon on the south pole in Hubble images since 1990. Images from NASA’s Cassini spacecraft, which orbited Saturn between 2004 and 2017, showed no inkling of a long-lived formation, either. The Hubble data confirmed the feature’s presence back to 2023.

A wave in a powerful Saturn jet stream

The wave sits within one of Saturn’s powerful jet streams and extends through multiple layers of the atmosphere, indicating it is not just a cloud-level feature, but a vertically extended atmospheric structure. The decagon’s apparent position shifts slightly, because Hubble captures images from different wavelengths. Those different wavelengths probe different altitudes in Saturn’s atmosphere. Simon said:

The most intriguing part to me is that this seems to have just formed recently. The question is, why did it suddenly form now when we haven’t seen one before?

The team plans to continue observing Saturn to determine whether the decagon settles into a long-lived, stable configuration like the northern hexagon or continues to evolve. Future observations also could help scientists determine what drives the wave, what it reveals about the atmospheric dynamics of giant planets throughout the solar system and how they may relate to those we see here on Earth.

Bottom line: Saturn’s south pole is now known to have a giant, evolving 10-sided wave, similar to the Saturn north pole hexagon.

Source: A decagon wave at Saturn’s south pole

Via NASA

The post Saturn’s south pole decagon confirmed! A mysterious 10-sided figure first appeared on EarthSky.