The Earth reradiates energy in the infrared region of the electromagnetic spectrum, specifically at wavelengths between 4 and 50 micrometers. This is also known as thermal radiation.

Here's why:

* Incoming solar radiation: The Sun primarily emits radiation in the visible and near-infrared wavelengths.

* Absorption and warming: The Earth's surface and atmosphere absorb a significant portion of this solar radiation, leading to warming.

* Reradiation: As the Earth warms, it emits radiation at longer wavelengths in the infrared region. This is the process known as thermal radiation.

While the Earth's reradiation occurs across a range of wavelengths, the peak emission falls around 10 micrometers. This is a key factor in the Earth's energy balance and the greenhouse effect.