Astronomers may have just pushed the upper size limit of what counts as a planet, thanks to new insights into how giant worlds form.
New observations from NASA’s James Webb Space Telescope (JWST) suggest that even extremely massive gas giants — once thought too large to form like ordinary planets — may grow through the same basic process, shifting how scientists differentiate massive planets from brown dwarfs.
The findings come from a close look at the HR 8799 system, a young, sun-like…
