The Cosmic Background Explorer (COBE ), also referred to as Explorer 66, was a NASA satellite dedicated to cosmology, which operated from 1989 to 1993.

Electromagnetic radiation refers to the waves of electric and magnetic fields that propagate through space.

The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their corresponding wavelengths and energies.

The Wikipedia page for "Electron" provides a comprehensive summary of the subatomic particle known as an electron.

Infrared is a type of electromagnetic radiation, which lies beyond the visible spectrum of light.

Kelvin is a unit of temperature widely used in the scientific field.

A photon is a fundamental particle in the field of physics, specifically in the area of quantum mechanics and electromagnetism.

X-ray, a type of electromagnetic radiation, is the topic of the Wikipedia page.