You don't even need to be a scientist in order to accept the lunar phases.
You only have to go outside once in a while and look at the moon.
It is unknown to scientists.
Any specific lunar phase can be observed only at the time when that lunar phase occurs, and not again for 29.53 days thereafter.
The lunar phase that precedes a full moon in the lunar cycle is the waxing gibbous phase. This phase occurs when the moon is more than half illuminated but not yet full.
Full.
We do . . . Full.
full moon phase
Full Moon.
Only at the Full phase.
waxing gibbous
Full Moon
Scientists studied data collected from seismometers left on the Moon's surface by Apollo missions, as well as data from lunar meteorites and satellite missions like the Lunar Reconnaissance Orbiter. By analyzing the Moon's seismic activity and gravitational field, scientists were able to develop a model of the Moon's interior structure, including its core, mantle, and crust.
It's always full at the time of a lunar eclipse.