_____possibly is not a thermal energy source.
Heater
Sun
Moon
The microwave
Heat energy is another name for thermal energy. Unlike the other three, a heater, the sun, and a microwave, the moon does not create any heat.
Thermal energy is used by warm-air heating systems to warm the air. The heated air is then forced via a network of ducts. The picture following shows a schematic of this style of heating system. Usually, a furnace that burns heating oil or natural gas warms the air.
Thermal convection, or the transfer of heat from a hotter area to a cooler one, occurs during the course of a day as a result of solar radiation. The Earth's objects and materials start to warm up as soon as the sun rises. Over the day, these materials warm up from sun radiation.
When food is heated by microwaves, electromagnetic energy is converted to thermal energy through the increased agitation of charged ions and water molecules.