Describing the Universe
The Electromagnetic spectrum & Telescopes
What is astronomy?
The part of the universe closest to earth is the solar system. This system comprises of earth, the sun and many other planets. It also contain smaller objects such as dwarf planets,asteroids, and comets. The solar system is part of a galaxy which is an assembly of stars,dust and gases. The Milky Way Galaxy is where the solar system is.
2. the visible and no visible parts of the electromagnetic spectrum.
The visible light spectrum is a fractional part of the electromagnetic spectrum,which is visible to the human eye,which are light receptors. Invisible spectrum are things like UV spectrum which falls outside the human visible range. Visible light waves are the only electromagnetic waves we can see. It's on the spectrum because it travels in electromagnetic waves.
3. refracting telescopes and reflecting telescopes.
Reflecting telescopes use lenses to gather and focus light from distant objects. Refractive telescopes have objective lens that bends light that passes through the lens and focuses on the light.Reflecting telescope use mirrors instead of lenses to gather and focus light.
the scientific study of the universe.
the totality of existence including planets,stars,galxies, the contents of intergalatic space and all matter and energy.
a collection of stars,dust,and gas bound together by gravity.
the average distance between he earth and the sun approximately 150 million kilometers. (symbol AU)
all of the frequencies or wavelengths of electromagnetic radiation.
the distance that light travels in one year, about 9.46 trillion kilometers.
a telescope that uses a set of lenses to gather and focus light from distant objects.
a telescope that uses a curved mirror to gather and focus light from distant objects.