When a burst of gamma-ray light reached Earth in October 2022 after traveling 2.4 billion years across the universe, it nearly instantly overwhelmed the instruments on some of NASA’s most advanced space telescopes. The detectors of the recently fully operational James Webb Space Telescope were effectively dazzled by something so far away and yet so intensely powerful that the engineers had not yet adjusted for it. The BOAT was the nickname given to the event by astronomers who were rushing to process the data, reflecting both its magnitude and their response to it. The Greatest of All Time. An explosion that was estimated to happen about every 10,000 years, and it just so happened to happen during the short period of time that humanity had instruments that could capture it in great detail. That timing is almost uncomfortably fortunate.
The most powerful events in the known universe are gamma-ray bursts, or GRBs as researchers refer to them. They can outshine a quintillion suns at once when they are at their best. It is practically impossible to retain that figure in any meaningful way, which may contribute to the fact that these events don’t get the public attention they most likely deserve.
| Topic | Gamma-Ray Bursts (GRBs) — The Universe’s Most Powerful Explosions |
|---|---|
| What Are GRBs? | Short-lived, extremely high-energy outbursts of gamma-ray light — the most powerful events in the known universe |
| Luminosity | Can reach a quintillion (10¹⁸) times the luminosity of the Sun |
| Discovery | Accidentally detected in 1963 by U.S. Air Force Vela satellites monitoring nuclear tests |
| First Publication | 1973 — Los Alamos National Laboratory astronomers confirmed extrasolar origin |
| Two Main Classes | Short GRBs (under 2 seconds) and Long GRBs (2+ seconds) — different origins |
| Short GRBs Cause | Collision of two neutron stars, or a neutron star and black hole |
| Long GRBs Cause | Collapse of massive stars (core collapse / supernova) |
| Associated Phenomena | Kilonovae (heavy element production), gravitational waves, afterglows |
| Heavy Elements Produced | Gold, silver, platinum — via kilonovae from neutron star mergers |
| Most Notable Event | GRB 221009A (“The BOAT”) — October 2022; 100x brighter than any previous GRB; occurs ~once per 10,000 years |
| BOAT Distance | 2.4 billion light-years away |
| Key Telescopes | NASA Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, James Webb Space Telescope |
| Gravitational Wave Link | Confirmed in 2017 — Fermi detected gamma rays 1.7 seconds after gravitational waves from same neutron star merger |
| Closest GRB on Record | Over 100 million light-years away |
| Reference Website | NASA Gamma-Ray Burst Science — Official |
Although the physics is true, the scale tends to slide off rather than stick because it is so disconnected from everyday human experience. The cumulative strangeness of how much these explosions continue to reveal about important topics, such as the formation of black holes, the origins of heavy elements, and the behavior of space-time itself, is what does catch your attention if you spend time studying the research. You’ll also notice how frequently each answer appears to contain two or three new questions.
It’s interesting to learn about the peculiar beginnings of the GRB discovery. In order to detect gamma rays from nuclear weapons tests being carried out in defiance of a recently signed treaty with the Soviet Union and the United Kingdom, the U.S. Air Force launched a series of satellites known as Vela in 1963. While many unexpected scientific discoveries were made during the Cold War, few were as significant as this one: the satellites discovered gamma-ray events, but they weren’t coming from Earth. By 1973, scientists at Los Alamos National Laboratory had confirmed in a paper that the bursts originated outside of our solar system. They unintentionally came upon the most violent phenomenon in the universe while out to observe the superpowers.
It took much longer to figure out what causes these occurrences. Based on duration, astronomers now categorize GRBs into two major classes. This distinction is important because it indicates completely different physical origins. Short bursts, lasting less than two seconds, are linked to neutron star collisions or neutron star mergers with black holes. These collisions result in what are known as kilonovae—explosions ignited by the radioactive decay of recently synthesized heavy elements—and are brief and extremely violent. Silver. Gold. Platinum.
The atoms that make up a person’s wedding ring or tooth filling were created during such incidents, dispersed throughout galaxies by the impact’s force, and ultimately found their way into the cloud of gas and dust that would eventually form our solar system. The deaths of massive stars, whose cores collapse when they run out of nuclear fuel and send shock waves outward in explosions we see as supernovae, are the source of long GRBs, which last two seconds or longer. In both scenarios, a newly formed black hole emits particle jets in opposing directions at almost the speed of light. These jets interact with nearby material to produce the gamma rays that we see.
The BOAT, GRB 221009A, was intended to neatly fall into the long-burst category. It was consistent with a massive stellar death, lasting seven minutes. And there was, in fact, a supernova at its center when the initial dazzling brightness subsided enough for JWST to study what remained. However, the burst had been about a hundred times brighter than anything that had ever been observed, and even a massive supernova couldn’t explain that. It was being amplified by something else.
The primary explanation relates to the jets’ geometry; if they are abnormally narrow, their energy is concentrated like a laser instead of dispersed like a floodlight, creating a beam that appears much more intense to anyone positioned along its axis. The BOAT’s jets seem to have been some of the narrowest GRBs ever measured. That could account for the brightness. The deeper puzzle is not entirely solved by it.
Then there was the gold that had vanished. According to current theory, some supernovae should produce heavy elements; the same explosive deaths of massive stars that produce GRBs may also disperse gold and platinum throughout galaxies, adding to the supply that eventually finds its way to planets and human hands. These components were sought after in the remnant by the BOAT research team.
None were discovered. This is the type of result that appears subtly in the literature and then gradually reverberates; it is not a dramatic announcement but rather a clear absence where something should have been, necessitating either a revision of the theory or a very specific set of circumstances under which the theory still holds. It’s still unclear which of those is true, so scientists are scheduling additional time on JWST to examine other supernova remnants in the hopes that the comparison will shed light.
It’s difficult to ignore the fact that gamma-ray bursts were found by satellites monitoring human violence and ended up serving as windows into cosmic ones. Despite this irony, the sheer amount of information these events contain is one of the reasons why scientists keep going back to them. Long after the initial explosion fades, a GRB afterglow—the longer-lasting glow that emits across radio, infrared, optical, ultraviolet, and X-ray frequencies—can persist for hours, days, or even years.
When light from a burst travels billions of light-years to reach us, it has passed through the early universe and contains information about the gas, dust, and structures it encountered. The event is the explosion. The archive is the afterglow. The study of these bursts is, in the strictest sense, a study of deep time—the universe’s history written in the most violent language it knows—because the closest GRB ever observed was still more than 100 million light-years from Earth.
