Electronic speed control. An electronic speed control or ESC is an electronic circuit with the purpose to vary an electric motor's speed, its direction and possibly also to act as a dynamic brake.
The ionosphere is the layer of the atmosphere that reflects radio waves. This effect is caused by the ionization, or electrical charging, of the gas particles present in the upper atmosphere by... The ionosphere is the layer of the atmosphere that reflects radio waves. This effect is caused by the ionization, or electrical charging, of the gas particles present in the upper atmosphere by X-rays and ultraviolet rays emitted by the sun.
Radio telescope. A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects.