Infrared

Definition

Infrared is a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. It is commonly used in astronomy to observe celestial objects that are not visible in the optical spectrum due to dust or distance.

5 Must Know Facts For Your Next Test

1. Infrared radiation has wavelengths ranging from about 700 nanometers (nm) to 1 millimeter (mm).
2. It is emitted by all objects based on their temperature, with warmer objects emitting more infrared radiation.
3. Astronomers use infrared telescopes to detect heat from stars, planets, and other celestial bodies obscured by interstellar dust.
4. The Earth's atmosphere absorbs much of the infrared radiation from space, so many infrared observations are conducted using high-altitude balloons or space-based telescopes.
5. Infrared spectroscopy helps identify molecular compositions and temperatures of distant astronomical objects.

Review Questions

• What is the wavelength range of infrared radiation?
• How do astronomers benefit from using infrared telescopes?
• Why are many infrared observations conducted outside Earth's atmosphere?

Related terms

Electromagnetic Spectrum: The range of all types of electromagnetic radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Visible Light: The portion of the electromagnetic spectrum that is visible to the human eye, with wavelengths approximately between 400 and 700 nanometers.

Spectroscopy: A technique used to analyze the light emitted or absorbed by objects to determine their composition and physical properties.