An illustration of the exoplanet K2-18b, which some research suggests may be covered by deep oceans. NASA, ESA, CSA, Joseph Olmsted (STScI)Daniel Apai, University of Arizona A team of astronomers announced on April 16, 2025, that in the process of studying a planet around another star, they had found evidence for an unexpected atmospheric gas. On Earth, that gas – called dimethyl sulfide – is mostly produced by living organisms. In April 2024, the James Webb Space Telescope stared at the host star of the planet K2-18b for nearly six hours. During that time, the orbiting planet passed in front of the star. Starlight filtered through its atmosphere, carrying the fingerprints of atmospheric molecules to the telescope.JWST’s cameras can detect molecules in the atmosphere of a planet by looking at light that passed through that atmosphere.European Space Agency By comparing those fingerprints to 20 different molecules that they would potentially expect to observe in the atmosphere, the astronomers concluded that the most probable match was a gas that, on Earth, is a good indicator of life. I am an astronomer and astrobiologist who studies planets around other stars and their atmospheres. In my work, I try to understand which nearby planets may be suitable for life.
K2-18b, a mysterious world
To understand what this discovery means, let’s start with the bizarre world it was found in. The planet’s name is K2-18b, meaning it is the first planet in the 18th planetary system found by the extended NASA Kepler mission, K2. Astronomers assign the “b” label to the first planet in the system, not “a,” to avoid possible confusion with the star. K2-18b is a little over 120 light-years from Earth – on a galactic scale, this world is practically in our backyard. Although astronomers know very little about K2-18b, we do know that it is very unlike Earth. To start, it is about eight times more massive than Earth, and it has a volume that’s about 18 times larger. This means that it’s only about half as dense as Earth. In other words, it must have a lot of water, which isn’t very dense, or a very big atmosphere, which is even less dense. Astronomers think that this world could either be a smaller version of our solar system’s ice giant Neptune, called a mini-Neptune, or perhaps a rocky planet with no water but a massive hydrogen atmosphere, called a gas dwarf. Another option, as University of Cambridge astronomer Nikku Madhusudhan recently proposed, is that the planet is a “hycean world.” That term means hydrogen-over-ocean, since astronomers predict that hycean worlds are planets with global oceans many times deeper than Earth’s oceans, and without any continents. These oceans are covered by massive hydrogen atmospheres that are thousands of miles high. Astronomers do not know yet for certain that hycean worlds exist, but models for what those would look like match the limited data JWST and other telescopes have collected on K2-18b. This is where the story becomes exciting. Mini-Neptunes and gas dwarfs are unlikely to be hospitable for life, because they probably don’t have liquid water, and their interior surfaces have enormous pressures. But a hycean planet would have a large and likely temperate ocean. So could the oceans of hycean worlds be habitable – or even inhabited?
Detecting DMS
In 2023, Madhusudhan and his colleagues used the James Webb Space Telescope’s short-wavelength infrared camera to inspect starlight that filtered through K2-18b’s atmosphere for the first time. They found evidence for the presence of two simple carbon-bearing molecules – carbon monoxide and methane – and showed that the planet’s upper atmosphere lacked water vapor. This atmospheric composition supported, but did not prove, the idea that K2-18b could be a hycean world. In a hycean world, water would be trapped in the deeper and warmer atmosphere, closer to the oceans than the upper atmosphere probed by JWST observations. Intriguingly, the data also showed an additional, very weak signal. The team found that this weak signal matched a gas called dimethyl sulfide, or DMS. On Earth, DMS is produced in large quantities by marine algae. It has very few, if any, nonbiological sources. This signal made the initial detection exciting: on a planet that may have a massive ocean, there is likely a gas that is, on Earth, emitted by biological organisms.K2-18b could have a deep ocean spanning the planet, and a hydrogen atmosphere.Amanda Smith, Nikku Madhusudhan (University of Cambridge), CC BY-SA Scientists had a mixed response to this initial announcement. While the findings were exciting, some astronomers pointed out that the DMS signal seen was weak and that the hycean nature of K2-18b is very uncertain. To address these concerns, Mashusudhan’s team turned JWST back to K2-18b a year later. This time, they used another camera on JWST that looks for another range of wavelengths of light. The new results – announced on April 16, 2025 – supported their initial findings. These new data show a stronger – but still relatively weak – signal that the team attributes to DMS or a very similar molecule. The fact that the DMS signal showed up on another camera during another set of observations made the interpretation of DMS in the atmosphere stronger. Madhusudhan’s team also presented a very detailed analysis of the uncertainties in the data and interpretation. In real-life measurements, there are always some uncertainties. They found that these uncertainties are unlikely to account for the signal in the data, further supporting the DMS interpretation. As an astronomer, I find that analysis exciting.
Is life out there?
Does this mean that scientists have found life on another world? Perhaps – but we still cannot be sure. First, does K2-18b really have an ocean deep beneath its thick atmosphere? Astronomers should test this. Second, is the signal seen in two cameras two years apart really from dimethyl sulfide? Scientists will need more sensitive measurements and more observations of the planet’s atmosphere to be sure. Third, if it is indeed DMS, does this mean that there is life? This may be the most difficult question to answer. Life itself is not detectable with existing technology. Astronomers will need to evaluate and exclude all other potential options to build their confidence in this possibility. The new measurements may lead researchers toward a historic discovery. However, important uncertainties remain. Astrobiologists will need a much deeper understanding of K2-18b and similar worlds before they can be confident in the presence of DMS and its interpretation as a signature of life. Scientists around the world are already scrutinizing the published study and will work on new tests of the findings, since independent verification is at the heart of science. Moving forward, K2-18b is going to be an important target for JWST, the world’s most sensitive telescope. JWST may soon observe other potential hycean worlds to see if the signal appears in the atmospheres of those planets, too. With more data, these tentative conclusions may not stand the test of time. But for now, just the prospect that astronomers may have detected gasses emitted by an alien ecosystem that bubbled up in a dark, blue-hued alien ocean is an incredibly fascinating possibility. Regardless of the true nature of K2-18b, the new results show how using the JWST to survey other worlds for clues of alien life will guarantee that the next years will be thrilling for astrobiologists.Daniel Apai, Associate Dean for Research and Professor of Astronomy and Planetary Sciences, University of Arizona This article is republished from The Conversation under a Creative Commons license. Read the original article.
Avi Loeb on 3I/ATLAS: Is This Interstellar Visitor Just a Comet—or Something More?
In July 2025, astronomers detected 3I/ATLAS, the third confirmed interstellar object. While viewed as a comet, Dr. Avi Loeb suggests exploring alternative hypotheses due to its unusual characteristics, igniting debate on how scientists address extraordinary claims within their research.
Last Updated on November 5, 2025 by Daily News StaffAI created image
In July 2025, astronomers using the ATLAS survey in Chile spotted something extraordinary: an object racing through our Solar System on a hyperbolic path—meaning it isn’t bound to the Sun. Officially named 3I/ATLAS, it’s only the third confirmed interstellar visitor ever detected, after 1I/ʻOumuamua (2017) and 2I/Borisov (2019).
While most scientists view 3I/ATLAS as a particularly strange comet, one prominent astrophysicist—Dr. Avi Loeb of Harvard University—has suggested that we shouldn’t rule out other possibilities too quickly.
Avi Loeb on 3I/ATLAS: Is This Mysterious Interstellar Comet Something More?
🔭 What Makes 3I/ATLAS So Unusual
Early data from NASA, ESA, and observatories worldwide show 3I/ATLAS behaving in ways that defy expectations:
Its coma (the cloud around the nucleus) is unusually rich in carbon dioxide, with a CO₂-to-H₂O ratio of roughly 8 to 1—far higher than typical comets.
A “forward glow” has been detected ahead of its motion toward the Sun, rather than a trailing tail pointing away.
Its trajectory aligns almost perfectly with the plane of the planets, a coincidence Loeb calls statistically rare (about 1 in 500 by his estimate).
These traits have made 3I/ATLAS a scientific curiosity—and for Loeb, a test case for how open-minded science should be.
🧠 Loeb’s Argument: Keep Every Door Open
In a series of essays on Medium and papers on arXiv, Loeb argues that science advances by questioning assumptions, even when those questions sound uncomfortable.
“Would it be better if 3I/ATLAS happens to be a spacecraft?” he asks half-jokingly in one post.
“We must be open to the possibility that new data on interstellar objects does not reflect the same science as past data on Solar System comets.”
Loeb doesn’t claim that 3I/ATLAS is alien technology—but he believes scientists should entertain all plausible hypotheses until the data clearly point one way.
In another article, he even scored the comet a “4 out of 10” on what he calls the “Loeb Scale” of possible technological origin—a tongue-in-cheek ranking that signals “worth watching, not worth panicking.”
🧩 The Scientific Response
Most astronomers strongly disagree with Loeb’s speculative framing. Observations from the James Webb Space Telescope and ground-based instruments reveal chemical and physical signatures consistent with a natural comet. According to Phys.org, the carbon-dioxide-dominant coma and early outgassing could simply mean 3I/ATLAS formed in a colder, more distant region of another star system.
NASA and ESA scientists emphasize that extraordinary claims require extraordinary evidence, and so far nothing about 3I/ATLAS violates known physics.
Still, Loeb maintains that “asking bold questions costs nothing.” His critics may roll their eyes, but they also admit that ʻOumuamua—the first interstellar object—surprised everyone too.
🚀 Why This Debate Matters
3I/ATLAS will swing closest to the Sun in late October 2025 before heading back into interstellar space forever. Whether it’s a dusty snowball or a cosmic enigma, it offers a rare chance to study material from beyond our Solar System.
Loeb’s writings—controversial or not—highlight an important truth about science: discovery begins when we admit we don’t yet know.
As he wrote in The Duck Test of 3I/ATLAS:
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“If it looks like a comet and behaves like a comet, then fine—it’s a comet.
But if not, we should be brave enough to ask why.”
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🌠 How to See a Comet Tonight Over Phoenix — Your Binocular Guide to the October Sky
Comet Night: Tonight in Phoenix, skywatchers can observe two comets, C/2025 A6 (Lemmon) and C/2025 R2 (SWAN). Both are visible through binoculars, with Lemmon potentially seen unaided under dark skies around 7:00 PM.
Phoenix skywatchers are in for a treat tonight as not one, but two comets — C/2025 A6 (Lemmon) and C/2025 R2 (SWAN) — make their way across the evening sky. Both are now bright enough to be seen through a good pair of binoculars, and one may even flirt with naked-eye visibility under dark conditions.
If you’ve ever wanted to catch a comet without fancy equipment, tonight’s your chance.
🌌 What You’ll See
Comet Lemmon (C/2025 A6) has been gaining brightness through October and now glows with a faint greenish hue, a sign of vaporized gases and carbon compounds in its tail. Under Phoenix’s clear skies, you may spot it as a fuzzy, glowing patch — brighter than most surrounding stars when viewed through binoculars.
The second visitor, Comet SWAN (C/2025 R2), is also within binocular range, adding to this rare double-comet spectacle. Though smaller and dimmer than Lemmon, it’s still worth the hunt.
🕗 When and Where to Look
Best viewing time: About 30–60 minutes after sunset (roughly between 7:00 and 7:30 PM in Phoenix).
Comet Lemmon: Look toward the northwest to west horizon, about midway between the bright star Arcturus and the handle of the Big Dipper.
Comet SWAN: Scan the southwest sky, just above where the Sun has recently set.
Both comets will be low on the horizon, so find an open spot with no buildings or trees blocking your view.
🔭 Tips for Best Viewing
Use binoculars (7×50 or 10×50 are ideal).
Step away from bright city lights — South Mountain, Papago Park, or the outskirts of Phoenix offer better visibility.
Allow your eyes 10–15 minutes to adjust to darkness.
Bring a stargazing app (like Sky Tonight or Star Walk 2) and search the comet names to track them in real-time.
If you have a tripod, use it — even slight hand movements can blur the view.
🌙 What to Expect
Comets aren’t as bright or defined as the ones we see in movies. Through binoculars, expect a small, glowing orb with a hint of a tail — especially for Lemmon. As the comet continues to approach the Sun in late October, it may brighten even further.
For many observers, simply knowing you’re seeing an object that’s traveled millions of miles through space makes the experience unforgettable.
⚠️ A Few Things to Note
Visibility can change night to night depending on brightness, weather, and moonlight.
If clouds or haze roll in, try again over the next few evenings — both comets will remain visible for several more nights.
Don’t be discouraged if you don’t spot it immediately — comet hunting takes patience, but the reward is worth it.
📸 Share the Moment
If you manage to snap a photo of Comet Lemmon or SWAN from Phoenix, tag @stmdailynews on social media and use #STMSkyWatch — we might feature your photo in an upcoming article.
For more astronomy updates, local skywatching events, and science news, visit STM DailyNews Astronomy.
🌠 Draconid Meteor Shower 2025: The Last Outburst Until 2078!
The Draconid Meteor Shower 2025 peaks on October 8 — possibly the last major outburst until 2078. Learn how, when, and where to watch this rare celestial event.
This October, skywatchers are in for a rare celestial show — one that won’t happen again for more than 50 years. The Draconid Meteor Shower is expected to put on a spectacular display on the evening of October 8, 2025, marking what astronomers predict could be the last major Draconid outburst until 2078.
🌠 The Draconid Meteor Shower 2025 peaks October 8 — and it could be the last major outburst until 2078! 💫 Look up after sunset to see Draco the Dragon breathe his final fire across the night sky. 🔥🐉 DraconidMeteorShower MeteorShower2025 SpaceNews Astronomy Skywatching MeteorStorm DracoTheDragon STMDailyNews Stargazing Comet21P SpaceEvent2025 🔗 Read the full story at stmdailynews.com ♬ original sound – STMDailyNews – STMDailyNews
🐉 What Are the Draconids?
The Draconids, sometimes called the Giacobinids, are born from dust and debris left behind by Comet 21P/Giacobini-Zinner. As Earth passes through the comet’s trail each October, the tiny fragments enter our atmosphere and burn up — creating bright streaks across the night sky.
Unlike most meteor showers that peak after midnight, the Draconids are best viewed right after sunset, when the constellation Draco the Dragon lies high in the northern sky.
“The Draconids are a bit of an oddball among meteor showers,” notes astronomer Peter Jenniskens. “They can go from almost nothing one year to a full-on meteor storm the next.”
🌌 When and Where to Watch
Peak Date: October 8, 2025
Peak Time: Around 7:00 PM UTC (early evening in North America and Europe)
Active Period: October 6–10
Best Viewing: Just after nightfall, facing northwest
This year’s shower comes with a catch — a bright full moon will be illuminating the sky, potentially washing out fainter meteors. Still, the brighter fireballs should be visible to the naked eye, especially from rural areas away from city lights.
💥 Why 2025 Is Special
Astronomers predict that in 2025, Earth will pass through dense trails of comet debris ejected during 21P/Giacobini-Zinner’s 2005 and 2012 orbits.
Models suggest a possible meteor outburst — perhaps as many as 150 to 400 meteors per hour under ideal conditions. Most of these will likely be faint, but a few bright “dragon fireballs” could stand out even in moonlight.
This will likely be the last significant Draconid outburst until 2078, as gravitational interactions — particularly with Jupiter — will soon pull the comet’s debris field away from Earth’s orbital path.
“The next time Earth crosses this kind of rich dust trail from Comet 21P will be decades away,” said meteor researcher Esko Lyytinen. “This is one of the last chances this century to see a strong Draconid display.”
🔭 Viewing Tips
Go dark: Find a spot away from city lights.
Look north: Aim your gaze near the constellation Draco, though meteors can appear anywhere.
Be patient: Let your eyes adjust to the darkness for at least 20 minutes.
Bring comfort: A reclining chair, blanket, and a warm drink go a long way.
Watch early: Unlike other showers, Draconids are best seen right after dusk.
🌠 A Dragon’s Last Roar
The Draconids have a history of surprises — outbursts in 1933 and 1946 produced thousands of meteors per hour, while other years offered only a few. Whether 2025 brings a brief flare or a full-blown celestial storm, it’s a chance to witness a piece of cosmic history.
So mark your calendars for October 8, step outside after sunset, and watch as Draco breathes his last fiery breath — at least, until 2078.
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Daniel Apai, Associate Dean for Research and Professor of Astronomy and Planetary Sciences, University of Arizona This article is republished from The Conversation under a Creative Commons license. Read the original article.
