At what temperature do molecules generally exist in the darkness of outer space?

Molecules in the darkness of outer space generally exist near absolute zero, which is approximately -273.15 degrees Celsius or 0 Kelvin. In the vast emptiness of space, where there is a lack of matter to transfer heat, temperatures can drop significantly. Most of the interstellar medium, which consists of gas and dust between stars, has temperatures that approach absolute zero.

At these extremely low temperatures, molecular motion is minimal, and thermal energy is significantly reduced. This low thermal energy is why you find that in the cold, dark regions of space, atoms and molecules are much less active compared to conditions found in environments closer to a star or planetary bodies. Higher temperatures, such as those near boiling points or even room temperature, would indicate energy levels conducive to molecular activity that are simply not present in the vacuum of outer space. Additionally, high temperatures would only be found in localized hot regions, such as near stars or in the aftermath of stellar explosions, rather than the general conditions across space. Hence, the correct answer reflects the characteristic coldness prevalent in the vacuum of space.