Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
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(Image credit: Greg Wyatt)The butterfly effect is a concept in the theory of chaos describing how tiny, initial changes in a complex system can result in massive, consequences. The metaphor coined by Edward Lorenz in the 1960s, suggests that a butterfly flapping its wings in Brazil could, through a chain reaction, trigger a tornado in Texas, highlighting extreme sensitivity to initial conditions. A butterfly is a minor mover drawn from the natural world. But for an intelligent technological civilization with major computational resources, could “flap its wings” in a deliberate fashion so as to accomplish a major goal. The related effect could serve as a technological sign…
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Stars in the dwarf galaxy Pictor II, which is more than 10 billion years old. The right panel shows a close-up of the star PicII-503, with the lowest iron content ever measured outside of the Milky-Way disk of stars. (Image credit: CTIO/NOIRLab/DOE/NSF/AURA)One of the remarkable insights in the biblical story of genesis is that the observable Universe had a beginning in time, akin to the modern notion of a Big Bang. This idea was not philosophically appealing to scientists like Albert Einstein, who in 1917 added a cosmological constant to his equations of General Relativity, in order to counteract the gravitational attraction of matter and radiation and allow for a static…
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(Image Credit: BBC News)At the end of a busy day yesterday with four interviews and a two-hour podcast with Brian Keating (posted here), I received a phone call from the New-York Post reporter David Spector, who asked me a simple question: “Will a stuffed animal survive free fall to the ground from the Earth’s stratosphere?” I took a pen and paper and within a few minutes derived the answer in following one-page note, accompanied by my email: “Dear David, I just derived a handwritten note that explains everything. A photo of it is attached below. Feel free to feature this image in your article because it derives the relevant numbers. Here is the explanatory text: an objec…
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Image credit: Dr. Omer EldadiMy Medium.com readership has grown to 140,000 followers. Each one of you represents something I deeply value: a mind that refuses to accept easy answers. Today, I’m inviting you to participate in a new academic study. I am collaborating with Prof. Gershon Tenenbaum, Prof. Nancy Cooke, and Dr. Omer Eldadi on research examining how people evaluate digital media content — the images and videos we encounter every day. Over the past four months, various YouTube channels used AI to generate videos of me, by imitating my image and my voice to spread misinformation with content that I do not approve of. One of the channels accumulated millions of view…
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Cells of the microorganism Deinococcus radiodurans after high-pressure impacts, imaged by a Transmission Electron Microscope. The cells impacted at 1.4 giga-pascals (SH 1.4 GPa) harbor similar morphology and cell-wall membranes as the unimpacted cells (SC). In contrast, cells exposed to 2.4 giga-pascals (SH 2.4 GPa) show some internal (filled black arrow) and cell wall (open black arrow) damage. (Image Credit: L. Zhao et al. 2026)Through five peer-reviewed papers, published here, here, here, here and here, I have explored with my students and postdocs the possibility of the transfer of life, so-called panspermia, in exoplanetary systems like TRAPPIST-1 as well as througho…
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“There are plenty of fish in the sea.” `Are we alone?’ Is the most romantic question in science. This image, obtained by Webb telescope, shows a stellar nursery, the Tarantula Nebula, with tens of thousands of young stars shrouded in cosmic dust. (Image Credit: NASA/ESA)Do we have cosmic neighbors? To find out, we can use powerful telescopes and remotely search for technological signatures of distant extraterrestrial civilizations in the form of electromagnetic signals, artificial lights, industrial pollution or megastructures. Alternatively, we could check for any packages delivered to our mailbox. U.S. Government data might help us make advances on the second option. Th…
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The Square-Kilometer-Array, located in South Africa and Australia, will offer new opportunities for eavesdropping on leakage of radio signals from extraterrestrial civilizations. (Image Credit: SKAO)The news about our technological era has been propagating at the speed of light for roughly 120 years, and reached only 20,000 nearby star systems. This constitutes a tiny fraction of only one part in ten million of the total number of stars in the Milky-Way galaxy. But it is important to recognize that in the next few centuries this number will grow in proportion to that time cubed, meaning that in a millennium — it will be about a thousand times larger. The growth will slow …
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Two-dimensional visualization of an Alcubierre warp drive, showing the opposing regions of expanding and contracting spacetime that displace the central region. (Image Credit: Wikimedia)Trustworthy military pilots report about Unidentified Aerial Phenomena (UAP) that exceed the performance envelope of human-made technologies. In a testimony before Congress, the Retired Navy Commander David Fravor reported seeing in 2004 white `Tic-Tac’ shaped objects that are of order 10-meter long , descending about 30 kilometers in less than a second. Some interpreters were quick to suggest that UAP might be warp drives invented by magical thinking in science fiction narratives. But the…
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(Image credit: Greg Wyatt)Since the instant that Galileo Galilei looked through his telescope at the sky, Astronomy was based on detecting light from the cosmos. The hot cosmic gas glowed early on, and we detected the radiation it emitted in the form of the cosmic microwave background. Afterwards, the cosmic gas condensed into galaxies — inside of which it fragmented into dense clouds that gave birth to luminous stars. When a star is born, the temperature at its core exceeds millions of degrees and so the fuel of hydrogen and helium starts to burn. Clusters of these nuclear fusion reactors are observed in the form of galaxies all the way to time when the Universe was just…
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A Sun-grazing comet, as observed by SOHO. (Image Credit: ESA/NASA/SOHO)The latest two puzzles about 3I/ATLAS stem from its large inferred size and mass (as reported here). First, its parent population cannot be supplied by the mass reservoir of planetary systems around old metal-poor stars (as I argued here). Second — its mass of a billion metric tons is 5 orders of magnitude larger than the final mass of 1I/`Oumuamua, implying that we should have discovered a hundred thousand interstellar objects on the mass scale of 1I/`Oumuamua before seeing one giant object like 3I/ATLAS (as I argued here). Altogether, the full list of 22 anomalies for 3I/ATLAS (summarized here) is pa…
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The Mass of 3I/ATLAS is About a Billion Metric Tons, at Least a Hundred Thousand Times That of 1I/`OumuamuaObservational data on the evolution of the mass loss rate of 3I/ATLAS dM/dt in various gasses: H2O (blue), OH (orange) and CO2 (green). The colored dashed-lines show various models for the mass loss rate. The solid pink and red curves display two preferred models to describe the combined total emission rate from water and carbon dioxide. The gray dotted line illustrates a previous model, favored in interpreting the rocket effect based on Hubble Space Telescope data (as reported here). (Image Credit: V. Thoss, A. Loeb and A. Burkert 2026)A new paper (accessible here) …
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An artist’s illustration of a magnetar — a rotating neutron star with a magnetic field of up to a quadrillion Gauss (a hundred billion Tesla). (Image Credit: Quanta Magazine)What would be the flagship signature of a very advanced, ambitious civilization? One possibility is the technology to propel a spacecraft the size of New-York City along with its population of ten million residents to the speed of light over a period of about a year. This requires an average acceleration of 1 gee, similar to the surface gravity of Earth. The acceleration phase would feel like living on the surface of Earth, as according to Albert Einstein’s theory of General Relativity — there is no f…
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The latest image of a fading 3I/ATLAS on March 11, 2026 at 19:22:54 UTC, based on ten 120 second, R-band exposures with a 25-centimeter telescope and an angular resolution of 1.38 arcseconds per pixel. Jupiter is outside the field of view. (Image Credit: Toni Scarmato)The interstellar object 3I/ATLAS is fading away. It will get closest to Jupiter on March 16, 2026 and then head out of the Solar System in a nearly symmetric fashion to the way it came in. I say `nearly symmetric’ because 3I/ATLAS exhibited a small non-gravitational acceleration, owing to a remarkable system of jets. The passage of 3I/ATLAS on a retrograde orbit within 5 degrees of the ecliptic plane provide…
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A Hubble Space Telescope image of 3I/ATLAS (Image Credit: NASA, ESA, STScI, D. Jewitt (UCLA), M.-T. Hui (Shanghai Astronomical Observatory))In a new paper (accessible here), I show that the recently inferred radius and interstellar number density of 3I/ATLAS-like objects, imply a local mass density that is larger by orders of magnitude than the available reservoir of heavy elements locked in low metallicity stars. This association was suggested by recent isotope abundance measurements. Either the inferred radius or number density are overestimated or the association with metal-poor stars is incorrect. The interstellar object 3I/ATLAS offers new insights into the mass rese…
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Spectral-line maps for 3I/ATLAS, observed with the Webb telescope’s NIRSpec: Top panel (a): water (H2O) at 2.7 micrometers; middle panel (b): carbon dioxide (CO2) at 4.3 micrometers; and bottom panel ©: carbon monoxide (CO) at 4.7 micrometers. Inset panels (upper right) show the respective line spectra. Lower left corner shows the direction of the Sun and nucleus velocity (v). (Image Credit: M. Cordiner et al. 2026)The chemical interactions of atoms are dictated by the number of electrons they possess. The electron cloud around the atomic nucleus balances the charge of the nucleus, which is proportional to the number of protons in it. Since the charge of the electron equa…
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A symmetric structure of a sunward anti-tail plus three equally-separated jets is apparent near the nucleus of 3I/ATLAS, after applying the Larson-Sekanina rotational gradient filter to two exposures by the Hubble Space Telescope on 2025–12–27. (Image Credit: T. Scarmato and A. Loeb 2026).After a four-hour interview with AJ Gentile in Las Vegas yesterday, I returned to Boston at midnight and before my morning jog — I answered the following set of questions from a journalist about the interstellar object 3I/ATLAS: - You previously estimated the likelihood that 3I/ATLAS is the creation of an alien civilization. A large body of observational data has now been accumulated. Ha…
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(Image credit: Greg Wyatt)In his Critique of Judgment (1790), Immanuel Kant famously asserted that “there will never be a Newton of the blade of grass, because human science will never be able to explain how a living being can originate from inanimate matter”. In a 21st century context, this philosophical insight means that while cosmologists understand the physical laws governing the movement of matter and radiation since the Big-Bang, it is far more challenging for astrobiologists to explain the origin of life from the same physical principles. The emergence of life-as-we-know-it, and in particular intelligent life, remains one of the most intriguing puzzles about the h…
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An equal-area projection map of impact locations (red dots) for 343 meteors with known velocities and impact energies recorded in NASA’s Center for Near-Earth Object Studies (CNEOS) Fireball and Bolide Database from 1994 February 1 to 2026 January 1. The estimated diameter of each object (ranging from 0.75 to 24 meters) is indicated by the relative size of its dot. The spatial distribution of impacts over Earth’s surface appears nearly uniform. (Image credit: I. Cho et al. 2026)Every year, an explosion with an energy output comparable to the Hiroshima atomic bomb occurs in our atmosphere without advance warning (as reviewed here). But in difference from the historic Hiros…
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Is the Mysterious Cylinder on Mars, Photographed in 2022 by the Curiosity Rover, a Human-Made Debris?A raw image from the Mast camera (Mastcam) onboard NASA’s Mars rover Curiosity, taken on 2022–08–07 at 20:58:23 UTC. (Image credit: NASA)A raw image from the Mast camera (Mastcam) onboard NASA’s Mars Curiosity rover, taken on 2022–08–07 at 20:58:23 UTC, displays a mysterious cylinder buried in the Martian regolith of the Paraitepuy Pass — a narrow gap in the Gale Crater situated on the slopes of Mount Sharp. This puzzling object was brought to my attention by Dr. Jan Špaček — who studies signatures of life on Mars and Professor Carol Cleland — who studies anomalies from a …
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Space Companies Did Not Pollute Our Night Sky for Billions of Years and Should Not Do So in the FutureSatellite streaks are evident in this long-exposure image of the sky over the NSF-DOE Rubin Observatory in Chile. (Image credit: Rubin Observatory/NOIRLab/SLAC/AURA/W.O’Mullane)If a future catastrophe will wipe out our technological civilization from the surface of Earth, will there be a technological relic that will survive intact for billions of years? One form of such relics are satellites above the altitude of geostationary orbits at 35,786 kilometers. These relics will continue to orbit the Earth long after they stop operating, since they do not have significant drag…
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The Rubin Observatory Could Discover Corner Reflectors or Artificial Lights in the Outer Solar System(Image credit: YIC-electronics)A week ago, the Rubin Observatory initiated the release of its much-anticipated flood of data from its 3.2 gigapixel camera (as announced here). Solar-system astronomers are accustomed to discovering asteroids by detecting the reflection of sunlight from their surface. However, a class of objects with the same surface area are potentially detectable to much greater distances in the outer solar system. They could be discovered, for the first time, by the Rubin Observatory. Natural objects which reflect sunlight get dimmer inversely with distan…
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(Image credit: Greg Wyatt)Some Hollywood stars, like James Dean, were brilliant but had a short life. The same holds true for the most luminous stars in the Universe, which shine for a short while in cosmological terms — merely a few million years. Stars are nuclear fusion furnaces, held together by gravity. They burn the abundant fuel of hydrogen and helium, left over from the Big Bang. Once their fuel is consumed, they die. When I once mentioned to a receptionist at a front desk of an office that everything is transient including the Sun, she responded: “Wow, the idea that the Sun will die is in conflict with my religion.” I apologized for being the bearer of bad news b…
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An original painting gifted to my office by the artist Jennifer Denning, titled “It’s a Freaking Spaceship”. (Image credit: Loeb photo collection)Yesterday, I received a delivery of a large package at the front door. It included an amazingly beautiful painting, donated to my office by the artist Jennifer Denning, titled “It’s a Freaking Spaceship”. I placed the painting above another piece of art that I had received last month from the artist Peter Tunney, titled “History Awaits” (reported here). These gifts supplemented two bronze sculptures of Galileo Galilei and 51 watercolors that I had received a few months ago from the artist Greg Wyatt (as reported here). You might…
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Orbit of 3I/ATLAS relative to the Sun in the ecliptic plane of the Earth around the Sun (with 1au being the Earth-Sun separation). Closest approach (perihelion) is marked by a yellow star, and the endpoints of the observational arc used for the orbit determination are indicated by open circles. Gray shading denotes the region where 3I/ATLAS goes under the orbital plane of Earth around the Sun, as the retrograde orbit of 3I/ATLAS is inclined by 5 degrees relative to the ecliptic. The Sun and the orbits of the major planets out to Jupiter are shown for reference. (Image credit: F. Spada, M. Królikowska and L. Dones, in a paper posted here on March 3, 2026)Today, a new pape…
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A Scientific Alternative to Government Disclosure: The Galileo Project is Now Capable of Discovering UAPThe triangulation-based path of an airplane (red) provides a distance measurement that is within 10% of its actual path (green), based on the latest analysis by the Galileo Project. (Image credit: Richard Cloete and Regina Sarmiento, Galileo Project)A few days ago, I celebrated my birthday by giving the colloquium at Harvard’s Institute for Thery and Computation, for which I served as director over the past twenty years. This hour-long lecture, available here, garnered by now of order ten thousand views. It overviews of the research performed within the Galileo Project …
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The philosopher-mathematician René Descartes published the phrase: “I think, therefore I am” in Discourse on the Method in 1637. (Image credit: painting by Frans Hals, “Portrait of the French philosopher and mathematician René Descartes (1596–1650)”)Recently, I noticed that some people around me are starting to lose their cognitive abilities as a result of excessive use of Artificial Intelligence (AI) platforms, such as ChatGPT, Claude or Gemini. This phenomenon resembles muscle loss from excessive use of public transportation as a substitute to walking. In academia, the only reliable way of testing the cognitive abilities of students right now is by placing them in a Far…
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An image of the interstellar object 3I/ATLAS, taken from a distance of 66 million kilometers on November 6, 2025, by the JANUS camera onboard ESA’s Juice mission to Jupiter. The direction of the Sun is indicated on the top left by a yellow arrow pointing straight down. The blue arrow marks the direction of motion of 3I/ATLAS, along the 7 o’clock direction. The inset displays concentric brightness contours around the nucleus. (Image credit: ESA/Juice/JANUS)The European Space Agency (ESA) just released here a new image of the interstellar object 3I/ATLAS, obtained by the JANUS camera onboard the Jupiter Icy Moons Explorer (Juice) spacecraft. JANUS is a multicolor optical ca…
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Let many flowers bloom. (Image credit: Loeb photo collection)Today is my 64th birthday. My way of celebrating it is through a public colloquium on my latest research. The lecture will be streamed live at 11AM New-York time on YouTube at the following link: https://medium.com/media/7af73164520d991e67a75bff8f577ac9/hrefYesterday, I had a fascinating 90-minutes interview with the brilliant NewsNation journalist, Natasha Zouves, which will be broadcasted within a few days. In it, Natasha confessed that she is worried about the consequences of an encounter with aliens and asked whether I would still welcome the encounter if I knew that I will die soon afterwards. I said that I…
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(Image credit: Greg Wyatt)Humans arrived at the cosmic stage relatively late, in the last 0.01 percent of cosmic history. We are not at the center of stage, since we reside on planet Earth which orbits the Sun and the Sun orbits the center of the Milky-Way galaxy, which is one out of a trillion galaxies in the observable Universe. Given that we arrived late and we are not featured centerstage, the cosmic play is not about us. Yet, we can still ask how we got here. The cosmic play started in the Big Bang, 13.8 billion years ago. We can only trace our roots out to the distance travelled by light since then. This sets the finite size of the cosmic stage which is visible to u…
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(Image credit: Skeptic Magazine)One way to look at the practice of physics is as a way to develop constraints on our imagination. There is an infinite number of possibilities for what the physical reality might be, but only a tiny minority of these possibilities is realized in nature. To find out which possibilities are real, physicists collect quantitative data from instruments. Theorists imagine possibilities and experimentalists narrow them down based on data. This resembles the work of a detective, faced with a mysterious crime scene. The limits imposed on our best imagined possibilities do not bring us pleasure, so humans tend to circumvent these constraints by atten…
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(Image credit: Galileo Project)Exciting news: the Galileo Project is seeking help from volunteers in labeling objects in the sky! The Galileo Project’s goal is to conduct a systematic scientific search for evidence regarding extraterrestrial technological artifacts. Our research team aims to bring the search for extraterrestrial technological signatures of extraterrestrial technological civilizations from accidental or anecdotal observations to the mainstream of transparent, validated and systematic scientific research. The Galileo Project is complementary to traditional SETI, in that it searches for physical objects near Earth that are associated with extraterrestrial te…
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U.S. President Donald Trump addresses a joint session of Congress on March 4, 2025. (Image credit: Win McNamee, Getty Images)On Saturday night, I was asked by the brilliant journalist Natasha Zouves on NewsNation: “On the Pod Force One podcast a few days ago, Lara Trump said about President Trump: “…there is some speech that he has, that I guess at the right time, I don’t know when the right time is, he’s going to break out and talk about and it has to do with maybe some sort of extraterrestrial life.” What is your message to President Trump?” I replied: “My message is simple. The State of the Union Address is coming up on Tuesday, February 24, 2026. Please include a stat…
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(Image credit: White House)https://medium.com/media/05c48d4023f33d5a599ad983bfbf158c/hrefA couple of hours after I posted my latest video, President Trump released the following statement: “Based on the tremendous interest shown, I will be directing the Secretary of War and other relevant departments and agencies to begin the process of identifying and releasing government files related to alien and extraterrestrial life, unidentified aerial phenomena (UAP), unidentified flying objects (UFOs), and any and all other information connected to these highly complex but extremely interesting and important matters. GOD BLESS AMERICA!” Following this statement, I was invited to p…
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The Fox News reporter Peter Doocy asked President Trump (left) and Avi Loeb (right) about aliens. (Image Credits: Fox News)Below is the transcript of a new short video that I just released on my YouTube Channel here. *** A few hours ago, on Thursday, February 19, 2026, President Trump was asked an interesting question by Fox News reporter Peter Doocy. The question followed comments that had received significant attention this week after former President Barack Obama said that aliens are real. President Trump was asked whether he had seen any evidence of nonhuman visitors to Earth. In response, President Trump said that Obama had revealed classified information and was not…
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(Image Credit: Judith Johnson)Below is an illuminating exchange that I had before my jog this morning about the publication crisis in academia. The exchange was triggered by my recent essay titled “Academic Harassment”, posted here. The incoming email read as follows: “Dear Avi, I’m a Professor of Mathematics at Chalmers University of Technology. I’ve came across your posts on Medium in connection to another question (which have only slight intersection with the one below). What I want to discuss is your recent post about a publication. It seems to me that most of science fields have recently encountered the same problem: The academia has scaled rapidly and so did the sys…
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A symmetric structure of three equally-separated jets is apparent near the nucleus of 3I/ATLAS, after applying the Larson-Sekanina rotational gradient filter to two exposures by the Hubble Space Telescope on 2025–12–27 UT. Two of the jets, separated by about 120 degrees, are prominent in both images, but their structure broadens into a wider fan on the right panel. Such morphological changes modulate the amplitude of the brightness variability. (Image Credit: T. Scarmato and A. Loeb 2026)In a new paper (accessible here) that I co-authored with the Italian observer Toni Scarmato, we use images from the Hubble Space Telescope to study the motion of the symmetric system of t…
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(Image Credit: Loeb image collection)In an early-morning research discussion with my colleague, Liam Connors, I noted that I have 11 interviews today. Liam wondered: “you have so many interviews with prospective PhD students?” and I explained: “no, these are interviews with television outlets in the US, Italy, Spain and Israel, a newspaper in the UK and half a dozen, hour-long podcasts.” Just the beginning of another busy day after my morning jog at sunrise. Yet, I remained optimistic about my tight itinerary. Every simple beginning holds the promise of a grand finale. Consider our Universe as a role model. Our vast cosmos gave birth to intelligence after 13.8 billion yea…
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(Image credit: Greg Wyatt)In July 2023, I led a Pacific Ocean expedition and brought back molten droplets of meteoritic residue retrieved from the site of the first recognized interstellar meteor, IM1 (as reported here). These 850 sub-millimeter spherules were delivered to the laboratory of my colleague at Harvard, Professor Stein Jacobsen — a world-renowned geochemist. Subsequently, I was asked whether we have detected new elements that do not appear in the familiar periodic table of elements on Earth. My answer was that Stein’s mass spectrometer and electron microprobe were designed to detect known elements. Admittedly, 84% of the matter in the Universe is made of a sub…
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A survey telescope’s detection captures a bright, actively outgassing interstellar object analogous to Wald’s detectable bombers, while numerous dark, inactive, or small ISOs pass undetected through the Solar System. The visible population represents only those objects that “survived” into our catalogs by meeting current detection thresholds. (Image Credit: O.Eldadi, G. Tenenbaum and A. Loeb)by Omer Eldadi (1), Gershon Tenenbaum (1) and Avi Loeb (2)Department of Psychology, Reichman University, Herzliya, IsraelDepartment of Astronomy, Harvard University, Cambridge, MA, USA(Submitted for publication as a perspective article in a peer-reviewed journal) Abstract The three kn…
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Bottom panel: Group photo of the “IceCube Neutrino Observatory Upgrade” team with the drill tower, hose reel and IceCube Lab in the background. Top panel: a multi-photomultiplier module being lowered into a borehole in the Antarctic ice. (Image Credit: Colton Hill and Yua Kamino, IceCube Neutrino Observatory/NSF)When I started my career in cosmology four decades ago, I was intrigued by an inevitable consequence of the Big Bang model. In addition to the relic radiation of the cosmic microwave background, discovered in 1964 — two years after my birth, there should also be a cosmic neutrino background filling up the Universe. The neutrinos decoupled from the cosmic soup of m…
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Galileo Project sensors on top of Sphere in Las Vegas are monitoring the sky in infrared and visible light, in search of anomalous objects. Outliers are identified by artificial intelligence algorithms. (Image credit: Alex Delacroix/Galileo Project)During a Valentine’s Day interview on Saturday, February 14, 2026 with the journalist Brian Tyler Cohen, posted here (and transcribed here), Former President Barack Obama was asked: “Are aliens real?” He responded: “They’re real, but I haven’t seen them. They are not being kept in Area 51.” Cohen then asked: “What was the first question you wanted answered when you became president?” to which Obama replied: “Where are the alien…
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The Last Universal Common Ancestor for life-as-we-know-it was a complex microbe that may have thrived in the shallow waters of early Earth, when the Moon loomed bigger in the sky as it was closer to Earth. (Image credit: Mark Garlic/Science Source)A new paper that I co-authored with my brilliant postdoc, Devesh Nandal (available here), suggests gratitude to our cosmic fortunes. Put aside your frustrations with terrestrial geopolitics or complaints about your fellow earthlings. Look up at the brightest stars in the night sky. According to the new paper, the real estate near these massive stars has a low value for life in our cosmic neighborhood of the Milky-Way galaxy. As …
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(Image credit: American Psychological Association)A few days ago, I co-authored a new paper with my brilliant postdoc, Richard Cloete, which reported here (and to a broader audience here) the statistically-robust discovery of two interstellar meteors from 2022 and 2025 in the CNEOS fireballs catalog of NASA/JPL — based on data from sensors onboard U.S. government satellites. Our rigorous data analysis used a details model which calibrated the uncertainties in the CNEOS database by comparing it to independent ground-based observations. A day after our paper was posted and submitted for publication, two things happened: - First, NASA flipped the sign on one of the velocity …
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Pointings by the Robert C. Byrd Green Bank Telescope in the Galactic Center region around the supermassive black hole, Sagittarius A*, with an overlaid total intensity mosaic of the region at a frequency of 1.28 gigahertz from the MeerKAT radio observatory. The central pointing, labeled as A00, indicates the Galactic center location at l = 0°, b = 0°. (Image credit: K. Perez et al. 2026)The ideal way to map the spacetime around a black hole is by a Global Positioning System (GPS) with a collection of precise clocks travelling through this spacetime. This was my insight in 2003, when I approached the postdoctoral fellow Eric Pfahl and suggested that we write a paper about …
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(Image credit: Greg Wyatt)Waterfalls are sites where gravity pulls water down a steep cliff. This setup endows the water with rapid motion as it falls down the gravitational potential well. In Albert Einstein’s theory of General Relativity, gravity is the curvature of spacetime and matter could reach the speed of light in highly distorted spacetime. There is no steeper cliff of spacetime than the vicinity of a black hole singularity, where infalling matter reaches the speed of light and the gravitational tide can rip apart any object. Paradoxically, the heating caused by the infall of matter makes some black hole environments the brightest sources of light in the Universe…
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A Swarm of 35-Million Interstellar Objects Was Just Discovered Within the Earth’s Orbit Around the SunThe gold aluminum cover of the Voyager Golden Record on the Voyager 1 and 2 spacecraft protects the “Sounds of Earth” gold-plated record from micrometeorite bombardment. (Image credit: NASA/JPL)Survey telescopes, like the existing NSF-DOE Rubin Observatory for the southern sky or the planned Argus Array for the northern sky, are sensitive to reflected sunlight from interstellar objects that are larger than our biggest rocket, Starship, namely more than a hundred meters in diameter. Fortunately, we can also discover much smaller interstellar objects by using the Earth’s at…
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(Image credit: Pete Saloutos/Getty Images)In a new paper that I co-authored with my brilliant postdoc Richard Cloete, available here, we report the identification of two previously unrecognized interstellar meteor candidates in NASA’s CNEOS fireball database. By exploiting an empirically calibrated uncertainty model from 2025 (reported here), we find two events that robustly exceed the escape velocity from the Solar System. CNEOS-22 (detected on 2022–07–28 in the eastern tropical Pacific) exceeds escape by 8.7 standard-deviations and CNEOS-25 (2025–02–12) exceeds escape by 5.5 standard deviations. For both events, none of a million Monte-Carlo realizations yield an orbit …
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The ATLAS experiment at CERN’s Large Hadron Collider. (Image credit: CERN)Before CERN’s Large Hadron Collider smashed particles at the highest energy ever achieved by humans — ten thousand times the proton-rest-mass, some expressed the concern that it might produce tiny black holes that would swallow Earth. The sobering realization missed by these doomers is that numerous cosmic-rays already collided with protons in the Earth’s atmosphere at much higher center-of-mass energies. Earth survived these numerous impacts throughout its 4.5-billion-year history, implying that we should not fear a black hole doomsday for center-of-mass energies up to a million times the proton re…
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(Image credit: Greg Wyatt)We are all familiar with the cosmic microwave background — the relic radiation left over from the hot, dense phase of the early Universe. This ancient light was emitted 400,000 years after the Big Bang. But was there any cosmic sound generated that early? Yes, there was. In the first 50,000 years after the Big Bang, radiation dominated the cosmic energy budget. The radiation was in perfect thermal equilibrium with ordinary matter, but featured tiny perturbations at the level of a part in 100,000. These perturbations propagated as sound waves. We observe them in the sky as brightness fluctuations of the cosmic microwave background. To understand t…
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Timothée Chalamet Appeared Next to the Galileo Project Observatory on Top the Las Vegas Sphere While Promoting the Movie “Marty Supreme”Image of Timothée Chalamet on top of the Las Vegas Sphere along with the Galileo Project Observatory units up there. (Image credit: Sphere Entertainment)This week, Timothée Chalamet popped up on top of the Las Vegas Sphere to promote his new movie, Marty Supreme, as the exosphere displayed an orange ping-pong ball underneath him. Remarkably, the images of him up there featured an observatory! Viewers of these images in the promotion video or related magazine articles (as featured here), wondered: what is this observatory? As I had mention…
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