Updated

Updated · spacedaily.com · Jul 24

MOA Estimates 20 Free-Floating Planets per Star, Putting Milky Way Total in the Trillions

Updated

Updated · spacedaily.com · Jul 24

MOA Estimates 20 Free-Floating Planets per Star, Putting Milky Way Total in the Trillions

1 articles · Updated · spacedaily.com · Jul 24

A nine-year MOA microlensing survey estimated about 21 free-floating or very wide-orbit planet-mass objects for every Milky Way star, implying trillions across the galaxy.
Six ultrashort lensing events under half a day in data from 2006 to 2014 drove the result, including a 0.057-day event identified as only the second Earth-mass candidate of its kind.
The estimate carries wide uncertainty—roughly 8 to 44 objects per star—and the team said microlensing cannot cleanly separate truly unbound planets from ones in extremely distant orbits.
The 2023 analysis also revises MOA's 2011 picture: the earlier apparent excess of Jupiter-mass wanderers largely disappears, replaced by a population skewed toward much lighter bodies.
NASA's Roman Space Telescope, due by May 2027, is expected to test the claim with a far larger space-based sample that could detect about 400 Earth-mass free-floating planets.

Sources

If only six brief flashes suggest trillions of rogue planets exist, how will NASA's upcoming Roman telescope prove this wild theory?

Could the mysterious Earth-sized objects roaming our galaxy actually be bound to invisible host stars rather than wandering completely alone?

With billions of starless planets wandering the Milky Way, could these dark, frozen worlds secretly harbor subsurface alien life?

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