Nature makes weird planets, and now this is among the weirdest: As big as Jupiter, made of carbon, blasted by high winds, and heated to 1900 degrees C by a dying, fast-spinning pulsar. No matter how bad things get here, we live on the best of all possible worlds. 🔭🧪 arxiv.org/abs/2509.04558

Meanwhile on Mars... The planet is covered with odd gullies that look like they were carved by running water. A cool new experiment demonstrates that they were probably carved by sliding, spitting chunks of dry ice. (Sorry, still no signs of life.) 🧪🔭 www.uu.nl/en/news/myst...

The X-10 graphite reactor at Oak Ridge went critical #OTD in 1943. Built as part of the Manhattan Project, it was the second artificial nuclear reactor (after Fermi's Chicago Pile 1) and the first to operate continuously. 🧪 ⚛️ Image: Ed Westcott

This mysterious object, called Capotauro, might be the earliest, most distant galaxy ever seen, containing some of the universe's first stars. Or it might be a mundane, nearby brown dwarf floating through our Milky Way. Nobody said cosmology was easy. 🧪🔭 arxiv.org/abs/2509.016...

You can almost reach out and touch it. What a shot of Comet Lemmon!

Astronomers sure do conjure up a lot of spooky images when they look out into deep space. A short Halloween thread: Let's start with the Cosmic Bat Nebula (LDN 43). 🧪🔭 apod.nasa.gov/apod/ap24102...

Fascinating graph shows the estimated total mass of all the mammals living on Earth. In 1850, it was evenly divided between wildlife and humans + domesticated animals. Today, humans and their livestock account for about 95% of the total. 🧪 www.nature.com/articles/s41...

Many objects in space have obscure names (HD 219134b) or unhelpful classical names (try to find the dog of Canis Minor, I dare you). But the Red Spider Nebula really looks like a spider in space--the breath of an old, dying star caught in a web of interstellar gas. 🧪🔭 esawebb.org/images/potm2...

I love this. If you live anywhere in the dark blue areas, you are closer to outer space (defined by the Kármán line) than you are to the nearest seashore. 🧪

Thanks to some vigilant friends out there, I have a nearly-complete 87-hour radar loop of #Melissa 's approach to #Jamaica. The loop abruptly ends when the radar is lost (either loss of communication with it or loss of the actual structure). bmcnoldy.earth.miami.edu/tropics/radar/

Spectacular time-lapse image of Comet Lemmon (C/2025 A6), taken by astrophotographer Michael Jäger. There might have been, um, a few satellites passing by during the long exposure. 🧪🔭 forum.vdsastro.de/viewtopic.ph...

More space beauty for your day: This new JWST image of Uranus shows exquisite detail in the rings, clouds, and huge polar cap. Imagine what it took to knock this planet on its side. Processing by Andrea Luck. 🔭🧪 www.flickr.com/photos/19227...

What a strange, beautiful shot of Comet Lemmon, now passing through the northwest sky after sunset. Here you see 2 comet tails (gas and dust), plus the unrelated zigzag trail of a passing meteor. And, inevitably, a couple satellite trails, too. 🧪🔭 star.ucl.ac.uk/~apod/apod/a...

China's Chang'e-6 sample-return mission discovered that the far side of the Moon is covered with fragments of carbonaceous, water-rich meteorites. Long ago, similar objects may have helped give Earth its oceans & delivered some of the raw materials for life. 🧪🔭 english.cas.cn/newsroom/res...

This is the most gloriously nerdy thing I've heard in a long time: My daughter's chem class is celebrating guaca-mole day today, because guaca-mole is made with avogadros. #iykyk

Monty Python understood p-hacking

Happy Mole Day to all who celebrate. www.compoundchem.com/2014/10/23/m... 🧪

Astronomers have determined that an elderly white dwarf star, 3 billion years into its final stage of life, is still busily crushing and devouring its planets. Scientific data on the left. Artist's interpretation on the right. 🧪🔭 keckobservatory.org/white-dwarf/

Astronomers have discovered rings forming around a Centaur. For real: Chiron (a comet-asteroid hybrid orbiting beyond Saturn) has set of rings that seem to be changing by the year. Regardless of what's happening on Earth, space continues to be amazing. 🧪🔭 iopscience.iop.org/article/10.3...

Earth's magnetic field is changing, with its weak spot (the South Atlantic Anomaly) growing significantly over the past decade. No, it's not doomsday...but it does affect the radiation doses hitting satellite that pass through that region. 🧪🔭 www.esa.int/Applications...

Into the 19th century, scientists commonly speculated that we're surrounded by inhabited worlds--not just Mars, but also Venus & the Moon. William Herschel, the century's greatest astronomical observer, even suggested there might be life on the Sun! 🧪🔭 articles.adsabs.harvard.edu//full/1981JR...

For sale: Empress's crown, lightly damaged

Wild! A meteorite may have struck the windshield of a 737 flying over Colorado, according to early reports. Whatever the object was, it cut a pilot's arm but did not seriously damage the plane. 🧪 avbrief.com/united-max-h...

A couple centuries ago, philosophers mused that we'd never know what stars are made of. Today, JWST is measuring the detailed composition of a protoplanet & possible moons forming around it. The results show complex reactions brewing around a newborn world. 🧪🔭 science.nasa.gov/missions/web...

It may look like CGI, but this is the real deal: It's an accurate 3D rendering of our galactic neighborhood, highlighting the locations where new stars are being born. This animation is based on measurements of 44 million stars by the Gaia space telescope. 🧪🔭 www.esa.int/Science_Expl...

What would it look like if a black hole devoured a star from the inside? NASA's Fermi space telescope may have spotted the answer: a 7-hour blaze of gamma rays, unlike anything seen before. When we explore, we discover amazing things. 🧪🔭 www.science.org/content/arti...

It's easy to laugh, but I honestly forget sometimes: Did I used to wait for press releases in the mail? Did I call university switchboards to track down researchers? Did I search for working payphones and call memorized phone numbers? (I know I did, and yet...)

An ultra-high-energy neutrino spotted by a detector in the Mediterranean Sea could be the result of an exploding black hole. This is a highly speculative interpretation--but exactly the kind of far-out exploration made possible by new neutrino experiments. 🧪🔭 news.mit.edu/2025/could-p...

Crazy but true: This is a real image captured by the Cassini spacecraft.

“Why is the night sky dark, if we live in an infinite universe?” Kepler, Halley, and Cheseaux all pondered this apparent paradox, but the question is commonly attributed to Heinrich Olbers, who was born #OTD in 1758. 🧪 🔭 Images: hyperphysics.phy-astr.gsu.edu/hbase/Astro/..., Wellcome Collection

Sure it's blobby, but this is our clearest look at two supermassive black holes in orbit around each other. The primary one is 18 billion times the mass of the Sun! The image was created using a space-based antenna that created a combined telescope 190,000 km wide. 🔭🧪 www.utu.fi/en/news/pres...

China's Tianwen-2 is on its way to Kamoʻoalewa, an asteroid that currently doubles as a "quasi-moon" of Earth. The spacecraft will collect samples & bring them back home. On its outward trajectory, Tianwen-2 looked back and got this lovely view of our planet. 🧪🔭 english.news.cn/20251001/ef3...

Astronomers have detected a dark blob of...something, billions of light years away. It's as massive as a million Suns & it emits no detectable radiation. It might be a clump of dark matter, revealing new details about the structure of the invisible universe. 🧪🔭 www.ucdavis.edu/news/astrono...

What's out there in the universe? We don't know until we look. The COWLS project scanned 42,000 galaxies and found hundreds of previously unknown gravitational lenses -- places where the pull of massive galaxies has warped space & bent starlight into arcs and rings. 🧪🔭 esawebb.org/images/potm2...

The Nobel Prize, widely considered the ultimate indicator of important science, has often gone off in weird directions due to politics & personalities. Like that year when an obsolete form of color photography beat out quantum physics for the physics Nobel. 🧪 physicsworld.com/a/nobel-priz...

Amazing: Comet ATLAS formed some 8 billion years ago. It made about 3 dozen circuits around our galaxy. It entered our our solar system & just passed 30 million kilometers from Mars... ...where ESA's ExoMars orbiter captured these images of the interstellar comet! 🧪🔭 www.esa.int/Science_Expl...

You can add John Clarke to the list of Nobel laureates who have published in Physics Today! 🥳 Here's a feature article he wrote in 1971 on quantum tunneling, Josephson junctions, and superconductivity.

This year's Nobel Prize in physics recognizes the discovery of practical ways to achieve quantum tunneling, which electrons can jump across "forbidden" barriers. I love the official explanatory cartoon from the Royal Swedish Academy of Sciences: www.nobelprize.org/prizes/physi... 🧪

VAR! In the early morning hours #OTD in 1923, Edwin Hubble took a photo plate of M31 that showed a Cepheid variable star. Using Henrietta Swan Leavitt’s distance-luminosity relationship, Hubble concluded that M31 is another galaxy outside the Milky Way. 🧪 🔭 ⚛️ Image: Carnegie Observatories

One of the key mysteries in cosmology is how quickly supermassive black holes formed in the early universe. The answer seems to be: a lot faster than we thought. The finding could help explain how formless gas evolved into a landscape of stars & galaxies. 🧪🔭 chandra.harvard.edu/photo/2025/r...

Data from the Cassini spacecraft shows that there is complex organic chemistry happening in the ocean of Saturn's moon Enceladus. It took 17 years to get the result! The finding boosts the case that life could possibly exist inside this little ice-covered world. 🧪🔭 www.esa.int/Science_Expl...

Our galaxy is full of rogue planets, worlds that live in darkness without a parent star. And now we've caught one as it forms, scooping up gas at a rate of 6 billion tons a second. 🧪🔭 www.eso.org/public/news/...

One of my favorite anecdotes from THE PREHISTORY OF THE FAR SIDE: "That doesn't sound like the Jane Goodall we know."

The world has lost its most powerful advocate for nature and hope. Yet many remain who will continue her legacy and I know she will continue to inspire generations more.

If you need a blast of beauty (and who doesn't?) I highly recommend browsing the new Astronomy Photographer of the Year winners. They're spectacular -- and neither of these shots even made it to #1. 🧪🔭 www.rmg.co.uk/whats-on/ast...

Meteorites striking the Moon release enough energy that we can see the flashes from Earth. The NELIOTA project has witnessed 193 of them (mapped here), creating a novel catalog of impact threats. A new upgrade means we'll soon see a lot more. 🧪🔭 www.esa.int/Space_Safety...

Happy 120th birthday, special relativity! Albert Einstein introduced special relativity in the paper "On The Electrodynamics Of Moving Bodies," published in Annalen der Physik #OTD in 1905. 🧪 ⚛️ 🔭 Manuscript: onlinelibrary.wiley.com/doi/abs/10.1... English: www.fourmilab.ch/etexts/einst...

Many years ago I had the honor of talking with George Smoot about his historic research measuring the cosmic microwave background. He ended up with a Nobel. I ended up with my first cover story (in Scientific American). He was thoughtful & generous--a source of joy & enlightenment. 🧪🔭

How do you land on another world, when that "world" completes a day in 5 minutes and is no bigger than a three-story house? Japan's Hayabusa2 spacecraft is set to find out in 2031 when it reaches asteroid 1998 KY26. 🧪🔭 noirlab.edu/public/news/...

The world's largest neutrino detector has just begun operations in Jiangmen, China. 🧪🔭 english.cas.cn/newsroom/cas...