How does heat travel in a vacuum?
The answer is: thermal radiation.
Heat is transferred in a vacuum through thermal radiation. Thermal radiation is a form of electromagnetic radiation, which means that it does not require a medium to travel through, unlike other forms of heat transfer such as conduction or convection. It is the same type of energy as visible light, and is emitted by hot objects as electromagnetic waves. These waves traveling through the vacuum of space carry energy from the Sun to Earth, allowing our planet to absorb the energy. Thus, thermal radiation is an important part of how our planet and its atmosphere are heated.
