DESCRIBING THE UNIVERSE
In terms of time, distance, and organization
What is astronomy?
OBJECTIVES
2. Compare - refracting telescopes and reflecting telescopes.
3. Explain - how telescopes for non visible electromagnetic radiation differ from light telescopes.
ASTRONOMY VOCABULARY
UNIVERSE
All existing matter and space considered as a whole; The universe is believed to be at least 10 billion light years.
LIGHT YEAR
A unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km.
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
Refracting telescopes use lenses to gather and focus light from distant objects.
REFLECTING TELESCOPES
Use mirrors to gather and focus light from distant objects.
DIFFERENCE BETWEEN AN ASTRONOMICAL UNIT AU AND LIGHT YEAR
THE ORGANIZATION OF THE UNIVERSE
DESCRIBE THE ELECTROMAGNETIC SPECTRUM
The invisible electromagnetic spectrum is not seen with human eyes unless you use a special instrument. Scientists discovered Radio and Infrared waves which are invisible unless used to be seen with a special instrument. Infrared is electromagnetic radiation that has waves that are longer than waves of visible light. Radio waves have even longer wavelengths than infrared waves do.
Visible and Invisible electromagnetic spectrums have things in common. They are both electromagnetic radiations.They are also both waves of electric and magnetic fields, and they come from stars. Both collect light to study the radiation, they both form energy, and travel at the same speed. They have a lot of things in common, the main difference is one is visible and the other is invisible.