  A key outstanding question in star and planet formation is how far the
initial mass function of stars and sub-stellar objects extends, and whether or
not there is a cut-off at the very lowest masses. Isolated objects in the
planetary-mass domain below 13 Jupiter masses, where not even deuterium can
fuse, are very challenging to observe as these objects are inherently faint.
Nearby star-forming regions provide the best opportunity to search for them
though: while they are young, they are still relatively warm and luminous at
infrared wavelengths. Previous surveys have discovered a handful of such
sources down to 3--5 Jupiter masses, around the minimum mass limit established
for formation via the fragmentation of molecular clouds, but does the mass
function extend further? In a new James Webb Space Telescope near-infrared
survey of the inner Orion Nebula and Trapezium Cluster, we have discovered and
characterised a sample of 540 planetary-mass candidates with masses down to 0.6
Jupiter masses, demonstrating that there is indeed no sharp cut-off in the mass
function. Furthermore, we find that 9\% of the planetary-mass objects are in
wide binaries, a result that is highly unexpected and which challenges current
theories of both star and planet formation.
