If we were to hypothetically place our planet in outer space, away from the influence of the Sun and other celestial bodies, the temperature would approach what is known as the cosmic microwave background temperature. This is the temperature of the universe as a whole, which is estimated to be around 2.7 Kelvin (-270.45 degrees Celsius or -454.81 degrees Fahrenheit).
In this scenario, without any external heat sources, the planet would gradually radiate its internal heat into space and cool down over time, approaching the cosmic microwave background temperature. However, the rate at which the planet cools would depend on factors such as its size, composition, and specific heat capacity.
If we were to artificially increase the temperature of the planet in outer space, it would require an external energy source to do so. Without a significant heat source, such as the Sun, it would be challenging to sustain a higher temperature. The planet's temperature would eventually equilibrate with its surroundings, radiating heat energy until it reached a new thermal equilibrium.
Conversely, if we were to decrease the temperature of the planet, it would require removing heat from the system. In the vacuum of space, where heat transfer occurs primarily through radiation, removing heat would be a slow process. The planet's temperature would gradually decrease until it approached the cosmic microwave background temperature.
It's important to note that placing a planet in outer space, away from its natural environment, would have numerous other consequences beyond temperature. The lack of atmospheric pressure and protection from cosmic radiation would be detrimental to life as we know it, and the absence of a gravitational force would affect various physical processes. This hypothetical scenario is purely theoretical and not feasible in reality.