Telescopes and the Electromagnetic Spectrum Section 3

Optical Astronomy Optical telescope Collects visible light for closer observation 2 lenses Objective lens: collects light and forms an image at the back of the telescope Eyepiece: magnifies the images from the objective lens

Without an optical telescope you can see about 6,000 stars With an optical telescope you can see millions of stars

Refracting Telescopes Use a set of lenses Curved objective lens bends light and focuses it to the eyepiece Eyepiece lens magnifies the image Disadvantage: if the curved lens is too large the glass will sag and distort the image

Reflecting Telescopes Use curved mirrors Large curved mirror reflects light to a focal point The focal point reflects light to the eyepiece Advantages: Mirrors can be made very large Mirrors are polished on one side to prevent flaws from glass Mirrors reflect light of all colors to the same place

What do you think would be an advantage to having a telescope in space compared to one on the ground?

Electromagnetic Spectrum Made of all the wavelengths of electromagnetic radiation Visible light is only a small portion Earth’s atmosphere allows these in…. Infrared, visible light, some ultraviolet, and radio Earth’s atmosphere blocks…. Gamma, X rays, some ultraviolet Astronomers can detect…. Visible light, infrared, and radio waves