If you went to the beach as a child, your parents probably slathered you with sunscreen in order to protect your delicate skin from the sun’s rays. More specifically, the sunscreen protected your skin from the sun’s ultraviolet (UV) rays.
Ultraviolet radiation is more dangerous than regular light rays because it is more energetic. This energy is a result of ultraviolet radiation’s shorter wavelength. The short wavelengths also cause UV to be invisible to the human eye. As a result, we need special equipment to detect ultraviolet light. It’s used in solar appliances, but we also have special telescopes that detect ultraviolet radiation.
As discussed in the article about infrared telescopes, objects with a temperature over absolute zero emit electromagnetic radiation. Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays are all types of electromagnetic radiation because they carry electromagnetic radiant energy through the electromagnetic field.
We are constantly in contact with electromagnetic radiation. Most notably, we see visible light, cook using microwaves, and get X-rays at the doctor’s office. As we discussed earlier, we also come in contact with ultraviolet radiation. The sun, stars, and other galaxies are responsible for ultraviolet radiation.
Ultraviolet radiation requires a special telescope for detection because it is invisible. The human eye blocks radiation with wavelengths of 300-400 nm. More so, humans lack the color receptor adaptors needed to see UV. As a result, optical telescopes cannot pick up ultraviolet radiation, which produces the need for ultraviolet telescopes, instead.
How Ultraviolet Telescopes Work
Just like all telescopes, ultraviolet telescopes use mirrors to gather and focus radiation. In fact, the mirror placement and technology are extremely similar to that of an optical telescope. Unlike other telescopes, though, the mirrors on ultraviolet telescopes are coated with a special material. This material makes it possible for the mirrors to reflect the ultraviolet light.
Ultraviolet telescopes also include detectors. Once the ultraviolet light is reflected from the coated mirrors, the detectors can pinpoint the ultraviolet light.
Another difference between ultraviolet telescopes and many other telescopes is that they should be placed outside the earth’s atmosphere. The reason for this is that the high-energy UV photons cannot penetrate the earth’s atmosphere. As a result, the UV would not reach the telescope if it were placed on the earth.
Since ultraviolet telescopes are only effective outside of the earth’s atmosphere, they are only capable through space flight, making them more modern technology.