o   Heliocentric model was theorized by Copernicus, which stated that the sun was at center of the universe.

-This was thought of due to retrograde motion

*Retrograde motion is a planets backward spin in the sky

-The ideas Copernicus were not accepted by the scientific community until other astronomers began to find evidence of the heliocentric models accuracy.

X-Ray | Radio | Reflecting | Refracting
X- Rays- The system contains computers, data records, and communication on equipment. Transmits information back to Earth. Includes an assembly of high-resolution mirrors. Equipped with a high resolution camera Records x-ray images of turbulent, high-tempera-ture events
Radio- A large dish, or antenna that resembles a large satellite dish. Reflects radio waves to focus above the dish. A receiver converts the radio waves into electrical signals. The information is stored in a computer for analysis.
Reflecting telescopes- brings visible light to a focus with mirrors. Most are used for scientific study. Located in observatories far from city lights .
Refracting telescopes- Uses lens to bring visible light to a focus. Used in long camera lenses. Used in astronomical lenses. Best used for long distance photos