Are sisters won't tell us
8 phases.
The changes in shape that the moon goes through are called phases.
It takes one month for the Moon to go through all of its phases one time.
6th graders 8th graders and 7th graders go there
every 29.53 days
Yes
29.5 days
Yes.
every four years
I am not aware of any. It does not go through "crescent" and "half" phases like our moon, because it is beyond earth's orbit, so it cannot have (from our view) "phases". And in and of itself, Neptune is one of the most featureless and uninteresting planets to view, much like Uranus.
Mercury, being an inner planet, does not exhibit phases like the moon does. However, it does appear to go through phases when observed from Earth due to its changing position relative to the Sun.
The complete cycle of the moon's phases, from one new moon to the next, takes about 29.5 days. This cycle includes the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent phases.