Massive Compact Halo Objects (MACHOs) are theoretical astronomical objects that could potentially make up a fraction of the dark matter in the universe. They are believed to be made up of normal, baryonic matter such as brown dwarfs, planets, or stellar remnants like white dwarfs or black holes. MACHOs are proposed as a possible explanation for the missing mass of the universe because they would not emit light and would be difficult to directly detect, making them a potential candidate for dark matter.
