What explains the extra heat found on Neptune?

Neptune has been observed to emit more heat than it receives from the Sun, which accounts for the extra heat found on the planet. This excess heat is primarily attributed to internal sources of heat rather than external factors like solar radiation absorption. The planet’s core is believed to retain heat generated from its formation and possibly from the slow gravitational contraction of its mass. Additionally, the presence of certain elements and compounds may contribute to the heat generation through processes like helium precipitation.

While other factors such as atmospheric pressure can influence temperature readings, they do not primarily explain the source of Neptune's extra heat. Radiative heat loss is a consideration for any celestial body, but in Neptune's case, the heat it radiates exceeds what it gains from solar input, which is specifically linked to internal sources. This distinction highlights the importance of understanding that some planetary bodies, particularly gas giants like Neptune, can have significant internal energy processes that contribute to their thermal characteristics.