Maryland Digital News > Blog > SCIENCE > The “most distant explosion ever” turned out to be rocket debris | by Ethan Siegel | Starts With A Bang! | Sep, 2025
A section of the GOODS-N field, which contains the galaxy GN-z11, the most distant galaxy ever observed. Originally, Hubble data indicated a redshift of 11.1, a distance of 32.1 billion light-years, and an inferred age of the Universe of 407 million light-years at the time this light was emitted. With better JWST data, we know this galaxy is a little closer: at a redshift of 10.60 corresponding to an age of the Universe of 433 million years. (Credit: NASA, ESA, G. Bacon (STScI), A. Feild (STScI), P. Oesch (Yale))
The universe is filled with unlikely events, but is also full of ways to fool ourselves.
The Great Observatories Origins Deep Studies North field (GOODS-N), cropped to show the Universe’s most distant galaxy, in red. A combination of Hubble and Spitzer data was used to discover this galaxy, whose distance has been confirmed spectroscopically, including more precisely and spectacularly by JWST in 2023. (Credit: NASA, ESA, P. Oesch (Yale University), G. Brammer (STScI), P. van Dokkum (Yale University), and G. Illingworth (University of California, Santa Cruz))
Its light arrives today after journeying for 13.4 billion years.
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Only because this distant galaxy, GN-z11, is located in a region where the intergalactic medium is mostly reionized, can Hubble reveal it to us at the present time. To see further, we require a better observatory, optimized for these kinds of detection, than Hubble. The JWST era has now knocked GN-z11 out of the top 10 spots of most distant galaxies, with all the record-holders being found and/or spectroscopically measured by JWST. (Credit: NASA, ESA, P. Oesch and B. Robertson (University of California, Santa Cruz), and A. Feild (STScI))
At this great distance, only aggregate starlight appears, not individual stars.
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The galaxy GN-z11 is so far away in the expanding Universe that the shortest-wavelength light we can see from it today, corresponding to light that was emitted in the ultraviolet part of the spectrum, is now at ~1,600 nanometers: more than double the maximum wavelength of the visible light capable of being detected by the human eye. (Credit: P.A. Oesch et al., Astrophysical Journal, 2016)
However, transient brightening events are detectable.
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Just hours after the gravitational wave signal arrived from two merging neutron stars in 2017, optical telescopes were able to hone in on the galaxy home to the merger, watching the site of the blast brighten and fade in practically real-time. This is a famous example of a transient event. (Credit: P. S. Cowperthwaite/E. Berger/DECAm/CTIO)
Cataclysms, like supernovae, can briefly shine as bright as an entire galaxy.
