When researchers cannot randomly assign participants and manipulate conditions in the real world, they can sometimes compromise by conducting experiments

The answer is natural experiments.

Explanation:

In natural experiments, the groups of participants are not controlled by the researchers. They are often done when lab experiments would interfere with the validity of the study, or when applying it would be unethical (for example, experiments related to diseases are often studied in a natural environment).

Natural experiments are recorded through observation. They usually seek to understand the effects of an environmental factor in a sample population.

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.