Describing The Universe

In terms of time, distance, and organization

What is Astronomy?

Astronomy is the scientific study of the universe. Astronomy also has a lot of value because it keeps us track of time and weather. We can also discover a new life. It's also important for the potential benefits of humans. Astronomers may also learn how to protect us from collisions between asteroids and earth.


1. Identify the visible and non visible parts of the electromagnetic spectrum.

2. Compare refracting telescopes.

3. Explain how telescopes for non visible electromagnetic radiation differ from light telescopes.

Astronomy Vocabulary

Describing The Electromagnetic Spectrum

The electromagnetic spectrum is all of the frequencies or wavelengths of electromagnetic radiation. The invisible and visible radiation are both traveling at the same speed which is 3,000 kilometers per second. The invisible wavelengths include infrared waves, microwaves, radio waves, ultraviolet rays, and gamma rays. The shortest wavelengths or visible light are blue and violet. The invisible waves are longest that are orange and red, it also requires a special instruments to be detected.

Comparing the refracting and reflecting telescopes

The refracting and reflecting telescopes are both used to focus light from distant objects. The refracting and reflecting telescopes are both optical telescopes. Refracting telescopes use a set of lenses to gather and focus light from distant objects, the lenses are difficult to be made. The lenses are clear objects shaped to bend light in special ways. The refracting telescope also has a lens that bends light. One problem with the refracting telescope is that the lens focuses in different colors of light at different distances. Reflecting telescopes use a curved mirror to gather and focus light from distant objects. This telescope was invented in the mid 1600s by Issac Newton. He also solved the problem of color separation that resulted from use of lenses. When light enters a reflecting telescope, the light is reflected by a large curved mirror to a second mirror. The second mirror reflects the light to the eye piece which is a lens that magnifies and focuses the image.

Telescopes for invisible light

Scientist have developed telescopes that detect invisible radiation. One problem with telescopes for invisible electromagnetic radiation is that earths atmosphere is like a shield against many forms of electromagnetic radiation. Each type of electromagnetic radiation provides scientists with information about objects in space. Water vapor can prevent gamma gamma rays, and most infrared and ultra violet rays, from reaching the surface. Ground based telescopes that are used to study these forms of radiation work best at high elevations, where the air is dry.

Spaced Based Telescopes

Ground based telescopes have been critical in helping astronomers learn about the universe valuable information has also come from spacecraft. Spacecraft that contains telescopes and other instruments have been launched to investigate planets, stars, and other distant objects.