Leonardo Petrillo

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In this viral clip from Cosmos Ep.1, Carl Sagan explains how Eratosthenes (276–194 BC) calculated Earth's circumference. 🔭 🧪 ⚛️

His estimate: 250,000 stadia ≈ 25,000 miles (~40,000 km).

Crazy accurate for 2200+ years ago!

#histsci #science

"The image shows a shell of thick gas and dust (red) expelled from the outer layers of a star as its core collapsed into a black hole. The inner regions show a heated ball of gas (white) continuing to fall into the central black hole."

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A recent Science paper claims a massive star in Andromeda basically vanished without first exploding in a supernova.

According to the authors, the star’s core collapsed directly into a stellar-mass black hole.

➡️ news.columbia.edu/news/scienti...

🔭🧪⚛️ #astronomy #science #cosmology #universe

Hypnotic photo of a curtain aurora that truly looks like a flying dragon.The image is extraordinary: an enormous serpentine green shape twisting through the night sky above a snow-covered landscape, with tiny human silhouettes that emphasize the epic scale. It looks like something straight out of a fantasy story, yet it is completely real.

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'Dragon Aurora over Norway' is an enchanting pic showing an impressive auroral curtain, captured by Marco Bastoni above Tromsø in Northern Norway.

The aurora's glittering green glow somehow reminds of a large dragon. 🔭

➡️ apod.nasa.gov/apod/ap18041...

🧪 ⚛️ #sciart #astrophotography #science

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Scientists no Longer Find Twitter Professionally Useful, and have Switched to Bluesky Synopsis. Social media has become widely used by the scientific community for a variety of professional uses, including networking and public outreach. For

Bluesky is the new science Twitter, new study by @whysharksmatter.bsky.social and Julia Wester concludes!

"Results show that for every reported professional benefit that scientists once gained from Twitter, scientists can now gain that benefit more effectively on Bluesky than on Twitter."

The Cone Nebula This is the iconic pillar in NGC 2264, ~2,500 away in Monoceros, rising from a fiery red sea. It looks dark and monstrous against a glowing crimson hydrogen backdrop, blue crest shining with scattered stars. Hits me hard every time—how stars savage the gas cloud to shape it, yet spark brand-new suns in the exact same chaos. Total proof the cosmos is raw, alive, and insanely gorgeous. Source: https://esahubble.org/images/heic0206f/ Credits: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

Mystic Mountain in the Carina Nebula This picture never fails to mess with me—like I’ve accidentally stepped into some brutal, jagged fantasy landscape that’s actively on fire. Hubble snagged it in 2010: a rough spike of gas & dust lost in the insane storm that is the Carina Nebula, sitting about 7,500 light-years out. Tiny new stars are losing their minds inside, shooting Herbig-Haro jets everywhere like they’re trying to escape. At the same time the monster stars right next door are sandblasting the whole thing with radiation, eating the edges away. The palette is ridiculous—sharp electric blue oxygen, warm green-gold from hydrogen and nitrogen, angry red sulfur glowing through it all. Feels straight-up like a Tolkien mountain caught in an apocalypse, pure violent energy. Just stars being born the hard way, screaming into existence. Wild. Source: https://science.nasa.gov/asset/hubble/hubble-captures-view-of-mystic-mountain/ Credits: NASA, ESA, M. Livio and the Hubble 20th Anniversary Team (STScI).

The Veil Nebula This pic always creeps me out in the best way—like catching the faint leftover smoke from a star that blew up around 8,000 years ago. It was a heavy one, roughly 20× our Sun, and now we’ve got this huge expanding shell called the Cygnus Loop, about 2,100 light-years out. Spreads over 110 light-years and still racing away at insane speed. When Hubble gets close you see these thin, wispy threads curling everywhere: soft blue-green oxygen, red hydrogen, some sulfur mixed in—looks like torn lace or drifting cosmic smoke. Quietly brutal. All that’s left of a massive star, yet those threads are basically planting the seeds for the next round of planets and suns. Eerie, gorgeous, and kind of humbling. Source: https://science.nasa.gov/image-detail/veil-nebula/ Credits: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

NGC 2014 and NGC 2020 in the Large Magellanic Cloud (Cosmic Reef) Way out in the Large Magellanic Cloud—163,000 light-years from home—you see this big angry red patch (NGC 2014) getting blasted bright by a bunch of really heavy stars, 10–20 times our Sun’s size. Then, right next to it, that perfect electric-blue bubble (NGC 2020) carved clean by one single Wolf-Rayet monster throwing out 200,000× the Sun’s light. The reds/oranges scream hydrogen + nitrogen; the sharp blue ring is oxygen going nuts. Looks exactly like some underwater coral reef… except the whole scene is only about 5 million years old. Source: https://science.nasa.gov/asset/hubble/cosmic-reef/ Credits: NASA, ESA and STScI

"...it's a mysterious and marvelous fact that our universe obeys laws of nature that always turn out to be expressible in the language of calculus as sentences called differential equations."

— Steven Strogatz, 'Infinite Powers'

🔭 🧪 #Hubble images' description, sources, credits in the ALT text

The following caption comes from this web page: https://science.nasa.gov/asset/webb/macs-j04175-1154-wide-field-nircam-image/ "A cosmic question mark appears amid a powerful gravitational lens in the James Webb Space Telescope’s wide-field view of the galaxy cluster MACS-J0417.5-1154. Gravitational lensing occurs when something is so massive, like this galaxy cluster, that it warps the fabric of space-time itself, creating a natural funhouse-mirror effect that also magnifies galaxies behind it. The rarely seen type of lensing captured here, which astronomers term hyperbolic umbilic, created five repeated images of one galaxy pair. The red, elongated member of this pair traces the familiar shape of a question mark across the sky due to the distortion, with another unrelated galaxy happening to be in just the right space-time to appear like the question mark’s dot – especially for humans who love to recognize familiar shapes and patterns."

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In case you missed it, here’s the #JWST wide-field view of the huge galaxy cluster MACS-J0417.5-1154, known for its stunning gravitational lensing effects and its wild ongoing merger dance. 🔭 🧪 ⚛️

➡️ webbtelescope.org/contents/new...

#cosmology #extragalactic #space #Astronomy #universe

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#JWST infrared deep field: golden-white distant galaxies on black space. Central soft blue #Chandra glow marks hot gas around a tight group of young galaxies. Brightest one has big diffraction spikes. Possibly the earliest protocluster seen—only ~1 billion years post-Big Bang.

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Here comes a jaw-dropping discovery: the most distant confirmed protocluster ever seen with X-rays! 🔭 ⚛️

Using #JWST & #Chandra together, astronomers spotted JADES-ID1—a massive structure in the making that’s forcing us to rethink how fast the cosmos grew up. 🧪

#cosmology #space #astronomy 1/10

It's a big, colorful shot of the Statue of Liberty Nebula (NGC 3576). Right in the middle, you can actually see why they call it that – there's this bright pinkish-red patch with a shape that really does look like the statue raising her torch. The whole thing glows in warm reds and pinks from hydrogen gas. Scattered across it are several small, perfectly dark blobs – those are dust globules. A few super-bright, almost glaring blue-white stars pop out against the nebula, and there are some faint wispy loops of gas curving off to the sides. About 100 light-years wide.

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This fantastic image shows NGC 3576, an emission nebula in the Sagittarius arm of our galaxy, dubbed 'The Statue of Liberty Nebula' because of the peculiar shape of the nebulous object in the center.

➡️ apod.nasa.gov/apod/ap16092...

🔭 🧪 ⚛️ #astronomy #space #universe #galactic

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Are we at a breakthrough in VUV laser tech?

It seems so: nuclear clocks could be way more accurate than what we have now, leading to substantial advantages.

Read the following. 1/3

⚛️ 🧪 #physics #science #laser #technology #clock

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Reposting this thread on #KatherineJohnson —perfect timing for the International Day of Women & Girls in Science on #Februar11, and right in the heart of #BlackHistoryMonth.

Her story just blows me away every time, showing how one person's grit ...

#WomenInSTEM #HistSci #WomenInScience 🧪 🔭 ⚛️

LA FISICA DIETRO CERTI EVENTI ESTREMI: L'EQUAZIONE DI CLAUSIUS-CLAPEYRON Negli ultimi anni sentiamo parlare sempre più spesso di “eventi estremi”: alluvioni improvvise, uragani intensi, ecc. Immagine tratta da...

🧪 The physics behind extreme weather: through the Clausius–Clapeyron law, warmer air holds more water vapor (~7% per °C), intensifying rainfall and fueling stronger storms. A simple equation with powerful climate implications. 🌡️🌪️ Read my blog post here: scienzaemusica.blogspot.com/2026/02/la-f...

James Webb Space Telescope NIRCam view of deep space showing hundreds of distant galaxies in different shapes and colors against black. A white zoom box in the center-right highlights a tiny faint red dot labeled GRB 250314A—the gamma-ray burst source and its very distant host galaxy.

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Fascinating stuff— #JWST has spotted the oldest supernova ever confirmed.

It exploded when the #universe was just ~730 Myr old (~5% of its current age).

The whole thing began with a very bright gamma-ray burst, GRB 250314A.🔭 🧪

➡️ science.nasa.gov/missions/web...

#space #astronomy #science

Stunning shot of ancient bristlecone pines in eastern California’s Ancient Bristlecone Pine Forest, under a sky bursting with the Milky Way. Saturn on the left and Mars look almost stuck to the branches, with the galaxy’s bright core lighting everything up. It gives you this crazy feeling of timelessness—super old stuff on Earth next to things billions of years older out there.

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This splendid image by Brad Goldpaint pays homage to the sky and ground, featuring some marvels of our planet and the majesty of our galaxy.🔭 🧪 ⚛️

The trees pictured here are incredibly ancient,...

➡️ apod.nasa.gov/apod/ap16061...

#astrophotography #astronomy #sciart #space #universe

Portrait of a young Enrico Fermi, from the personal collection of Emilio Segrè (Morgue 1960-33). Courtesy of Lawrence Berkeley National Laboratory / AIP Emilio Segrè Visual Archives. Non-commercial use.

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Picture a 25-year-old Italian guy who, in 1926, changed #physics ⚛️forever—paving the way for computers, smartphones, & understanding #stars. 🔭

This is #EnricoFermi & his famous “statistics.”🧪

Let’s walk through the story from Florence to “fermions,” 100 yrs later.

➡️ arxiv.org/abs/2602.04484

Take a good look at this close-up of Io — the terminator slices it straight down the middle. Right side catches full sunlight and lights up in these vivid yellow-oranges. Left? Mostly blacked out, but you can still make out stuff because Jupiter's glow is bouncing off it (that's the Jupitershine doing its thing). The ground's a mess: rough everywhere, spotted with these huge volcanic sinks called paterae, plus darker smudges — sulfur gunk or silicates most likely — and patches that glow a bit brighter. Those could be fresh lava spills or just sulfur dioxide frost hanging around.

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How intriguing is this view of Jupiter's rocky moon Io, the most volcanically active body in the Solar System? 🔭 🧪⚛️

This is a gift coming from Juno spacecraft that made a 2nd close flyby...

Pic by NASA/SwRI/MSSS

Mission Phase: PERIJOVE 58

➡️ missionjuno.swri.edu

#space #astronomy #science

Up close, Cassini caught Saturn’s rings glowing gold from behind, the Sun lighting them in that eerie backlight with sharp dark shadows slicing through. Right near the top-center sits this little white spark—Venus, not some distant star. Shot November 10, 2012. From Earth Venus blazes like the brightest “star” in the sky, yet out there it’s just a faint dot. Saturn’s average distance—1.4 billion km—really hits you then. We feel so small.

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What is that tiny white dot, just above and to the right of the pic center?

It's about the planet Venus, imaged by the wide-angle camera from the Cassini spacecraft on 10 Nov 2012. 🔭 🧪

➡️ photojournal.jpl.nasa.gov/catalog/PIA1...

Image by NASA/JPL-Caltech/SSI

#planetsci #histsci #science

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This thread is a true masterpiece! And I completely agree that not awarding the Nobel Prize to Madame Wu was an injustice of gigantic proportions.

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Chien-Shiung Wu shattered one of physics' core assumptions. ⚛️

In 1957, she proved that nature does distinguish between left & right in weak interactions.

Before her, physicists thought mirrors didn't matter in fundamental laws.

She flipped that on its head.🧪

#histsci #WomenInSTEM #science

Image description from the Hubble/ESA release: "A disc-shaped galaxy. It glows brightly at the centre and shines a faint white light all around it. The disc is made up of tightly-packed rings of dust, some darker and some lighter. Wide, long lanes of dark reddish dust cross the galaxy in front of its edge, blocking out some of its light; the long strands twist and break apart at each side. A couple of nearby stars and distant galaxies are also visible on the black background."

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Ever heard of lenticular galaxies?

#Hubble just captured one 187 Mly away in Pegasus. 🔭🧪

It's NGC 7722: nothing like a classic spiral or a plain elliptical.

This amazing hybrid looks like a cosmic lens with dark dust rings swirling all around it.

➡️ esahubble.org/images/potm2...

#universe

The image is clearly stunning but so is your thread. It was really interesting to read about recent revisions of a well-known astronomical scenario.

Shadowy Italian Alps peaks below a deep inky-blue sky full of sharp stars. Andromeda glows softly in the middle as a big oval patch, brighter at the center, fading into a hazy ring.

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This amazing pic by Matteo Dunchi features the Andromeda Galaxy (M31), rising over the Italian Alps in July 2015.

Although M31 appears in the sky as a faint and fuzzy blob to the unaided eye, its light is about 2.5 Myr old, making it likely the oldest...

➡️ apod.nasa.gov/apod/ap15081...

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This thread of mine from June 2025 is about MoM-z14, the most distant galaxy spectroscopically confirmed to date, discovered by #JWST 🔭

Well: months later, NASA has just released the official press release (Jan 28, 2026)➡️ science.nasa.gov/missions/web...

And the arXiv paper ...

🧪 #cosmology 1/2

Image of Abdus Salam in his maturity, wearing a pinstriped double-breasted suit, while writing on a blackboard and pointing with the index finger of his left hand, presumably looking at the camera. He is wearing glasses and has a very subtle smile. Image source: https://www.imperial.ac.uk/about/introducing-imperial/our-people/award-winners/nobel-winners/abdus-salam/

January 29, 1926: the great theoretical physicist Abdus Salam was born in the Punjab Province of British India (now in Pakistan).

In 1979, he shared the Nobel Prize for Physics with Steven Weinberg and Sheldon Glashow, ...

⚛️ #histsci #physics #science 🧪

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"The image showcases X-ray and optical data of the likely black hole triplet, SDSS J0849+1114. The main panel of the graphic is an optical image that reveals the unique layout of the merging galaxy system, almost shaped like a hummingbird in flight. A pullout from the central region contains an X-ray image with three sources in a clump of purple. In the optical image, the galaxy system is colored in soft yellows, brown and pale blue. The X-rays in the pullout are from NASA's Chandra X-ray Observatory (purple) while the optical light image was created from data from the Hubble Space Telescope and the Sloan Digital Sky Survey (red, green, and blue)."

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In 2019, using data from telescopes on the ground as well as several in space including Chandra, Hubble, WISE, SDSS and NuSTAR, astronomers discovered a system of 3 supermassive black holes (SMBHs) on a collision course.

➡️ chandra.si.edu/press/19_rel...

🔭 🧪 #cosmology #science #Universe

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We must dismantle the myth that loving #physics requires a ‘tomboy look’—brilliant minds have no gender!

Together, let’s change the future of #WomenInSTEM!

⚛️ 🧪 🔭 #science #Education

As a teacher with a master’s in #physics and years of science communication experience, I’ve witnessed these sexist stereotypes firsthand—they actively discourage girls from pursuing #STEM.

It is a global issue.

⚛️ 🧪 🔭 #WomenInSTEM #science #Education

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Thin crescent of Uranus, illuminated against black space. Processed color composite by Emily Lakdawalla from Voyager 2 frames taken through orange, green, and violet filters on January 25, 1986; the resulting hue appears subdued grayish-blue/violet in this version.

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Can you believe it? 40 years since #Voyager2 nailed that crazy crescent Uranus pic. 🔭

Jan 25, 1986 – probe's already booking it out of there after the real close shave on the 24th.

Just this thin glowing slice against black space... hits different every time.

🧪 #histsci #planetsci

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Thamserku right there, all snowy and razor-sharp in Nepal, and above it this cloud that looks straight out of a dream. Pale pink, light green, turquoise fading into almost-nothing violet, all happening along the edges—like the light just shattered into little colored bits.It's not a full rainbow, nah, just pieces of one. Tiny tiny droplets, all the same size, scattering the sun in exactly that way. The mountain underneath stays freezing, white and icy blue, but the cloud is glowing warm, almost unreal, with that low sun hitting it from behind.

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Do you know the effect called cloud iridescence or irisation?🧪

When parts of clouds are thin and have similar size droplets, diffraction can make them shine with colours like a corona.🔭

In fact, the colours are essentially corona fragments. ⚛️

➡️ apod.nasa.gov/apod/ap14070...

#sky #Nature

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Charcoal drawing on cardboard: a bouquet of red and yellow flowers emerging from a base of lanceolate leaves. The bouquet is held by a low, rounded vase featuring two wide, circular handles. At the top of the drawing, written in red: "Thank you for..." Author: myself

In the quiet surrender of expectations—when the heart has wearied itself into a fortress of self-sufficiency, no longer extending fragile bridges toward others—a single "thank you" emerges not as mere courtesy, but as an unbidden spark in the vast gray expanse of indifference.

#art #Gratitude

Magical autumn sunset scene at Lake Viverone, Piedmont, Italy: warm village lights glow in the foreground, the calm lake reflects the sky, and distant mountains fade into soft focus. Pastel pink and light orange clouds at sunset contrast beautifully with the twilight sky, while the faint comet resembles a translucent whitish dragonfly gently descending into the rosy clouds. Via: https://commons.wikimedia.org/wiki/File:Comet_C-2023_A3_Tsuchinshan-ATLAS_over_Viverone_Lake,_ITALY.jpg

Comet C/2023 A3 (Tsuchinshan-ATLAS), photographed by Andrea Cappe on October 13, 2024 at 19:38 CEST, Roppolo, Italy.

This is one of the most evocative captures of that comet I have seen.

Image: Via Wikimedia Commons

License: CC BY-SA 4.0

🔭 🧪 #sciart #science #nature #comet

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