[14][16] The burst saturated the Fermi Gamma-ray Space Telescope's detector,[17] which captured gamma ray photons with energies exceeding 100 GeV.

[19] When the burst's radiation arrived at Earth the Large High Altitude Air Shower Observatory (LHAASO) alone saw more than 5,000 such VHE photons.

Some of these photons arrived at Earth carrying a record 18 TeV of energy,[20][21] which is more than can be produced at the Large Hadron Collider (LHC) at the European Center for Nuclear Research (CERN).

GRB 221009A was subsequently observed by the Neutron Star Interior Composition Explorer (NICER),[14] the Monitor of All-sky X-ray Image (MAXI), the Imaging X-ray Polarimetry Explorer (IXPE),[30][31][8] the International Gamma-ray Astrophysics Laboratory (INTEGRAL), the XMM-Newton space telescope,[32] the Large High Altitude Air Shower Observatory (LHASSO)[33][34] and many others.

[22][35] Observations with the James Webb Space Telescope (JWST) have confirmed that GRB 221009A was caused by a massive star undergoing a supernova.

Lightning detectors in India and Germany picked up signs that the Earth's ionosphere was perturbed for several hours by the burst, though only mildly,[37][17][4] as well as an enormous influx of electrically charged particles,[38] showing just how powerful it was.

[17][42] Dan Perley, an astrophysicist at the Astrophysics Research Institute at Liverpool John Moores University, stated that "There is nothing in human experience that comes anywhere remotely close to such an outpouring of energy.

"[44] The power of gamma-ray bursts may be gauged by the degree of interaction between the gamma rays they emit and the ubiquitous lanes of interstellar dust in deep space.

[12] Reanalysis of the data from Fermi Gamma-ray Space Telescope revealed with 6.2σ significance an emission line 5 minutes after the burst was detected and after it had dimmed enough to end saturation effects of the instruments.

[35][10][41][11] The extremely bright peak and long afterglow may help physicists study the manner in which matter interacts at relativistic speeds, the only known regime capable of generating gamma ray photons with more than 100 GeV of energy.

[14] GRB 221009A has enabled scientists to impose stringent limits on any violations of Lorentz invariance proposed in certain theories of quantum gravity.