Describing The Universe
The Electromagnetic Spectrum and Telescopes
What is Astronomy?
Objectives:
2. Identify the visible and no visible parts of the electromagnetic spectrum
3. Compare refracting telescopes and reflecting telescopes
4. Explain how telescopes for no visible electromagnetic radiation differ from light telescopes
Universe
Noun All existing matter and space considered as a whole
Light Year
Noun A unit of astronomical distance equivalent to the distance that light travels in one year
Astronomical Unit
The average distance between the Earth and the sun; approximately 150 million kilometers
Electromagnetic Spectrum
All of the frequencies or wavelengths of electromagnetic radiation
Refracting Telescope
A telescope that uses a set of lenses to gather and focus light from distant objects
Reflecting Telescope
A telescope that uses a curved mirror to gather and focus light from distant objects.
Difference between an Astronomical Unit and a Light Year
The difference between an astronomical unit and a light year is that in a light year it is the distance that light travels in one year which is approximately almost 10 trillion km/s. An Astronomical Unit is the average distance between the Sun and the Earth, which is 1500km.
The Organization of the Universe
Describe the Electromagnetic Spectrum
On the visible electromagnetic radiation the shortest wavelengths are the blue and violet and the longest are the red and orange. Also, only visible light can be seen by the human eye. When light passes through a prism it is broken into different colors; each wavelength represents a different color.
The invisible electromagnetic radiation is not visible to the human eye, and to see it you would need special instruments. The wavelengths include infrared waves, microwaves, radio waves, radio waves, ultra violet rays, x rays and gamma rays.
Comparing a Refracting and Reflecting Telescope
Some things a refracting and reflecting telescope have in common are that they're both optical telescopes and are both used to study radiation. Also, both telescopes.
The reflecting telescope is a telescope that uses a curved mirror to gather and focus light from distant objects. It uses a curved mirror, then refocuses on a second mirror and then the second mirror sends it to the eye piece. For this telescope it is not difficult to make very large mirrors; with that it can gather and analyze more light.
Space Based & Invisible Light Telescopes
The space based telescopes investigate planets, stars, and other distant objects. In space, Earths's atmosphere doesn't interfere detecting the the electromagnetic radiation. The "Compton Gamma Ray" observatory isn't in space anymore but it detected gamma rays from objects, like black holes. The "Spitzier Space Telescope" (launched in 2003) was used to detect infrared radiation. In 2011, the "James Webb Space Telescope" was supposed to be launched to detect infrared radiation from objects in space.