Unit E Section 3,1 Flashcards
Who made one of the first telescopes?
In 1608, a Dutch optician named Hans Lippershey
but it is Galileo who has been credited with first using the telescope to study the visible features of the night sky.
Why are optical telescopes known as “light collector”
series of lenses and mirrors gather and focus the light from stars so that we can see it
The larger the area of the lenses or mirrors in a
telescope……..
the greater the ability of the telescope to see the faint light of objects that are very distant.
What was the first telescope that was ever designed?
a simple refracting telescope.
what are refracting telescopes?
Refracting telescopes use two lenses to gather and focus starlight
What is the disadvantage of refracting telescopes?
There is a limit to how large a refracting telescope can be.
Any diameter over 1 m causes the glass in the lens to warp under its own weight
In a refracting telescope…..
The lens on which we put our eyes is called:
eye piece lens
In a refracting telescope…..
The lens on which we put our eyes is called:
eyepiece lens
In a refracting telescope…….
The lens that is opposite of the eyepiece lens is:
primary light-gathering
lens
What are Reflecting telescopes?
Reflecting telescopes use mirrors instead of lenses to gather and focus the light from stars
How is the reflecting telescope built?
At one end of a reflecting telescope is a large concave
mirror, which is made from a glass-like material that is coated with a thin layer of metal. The metal, such as aluminum, is polished to a shiny finish so that it can reflect the faintest light it receives.
What is spin casting?
a method to form the largest mirrors
What does the process of “spin casting” require?
This process requires that molten glass be poured
into a large spinning mold.
the spinning mold forces the melted glass to the mold’s outside edge.
After the glass cools and solidifies, technicians grind it into the desired shape for the telescope
What is the advantage of spin casting?
is quicker and less costly than previous methods of making mirrors
Parts of A reflecting telescope?
primary light-gathering
mirror focus
eyepiece lens
secondary mirror
interferometry
This technique of using telescopes in combination is known as interferometry.
Why are telescopes sometimes combined?
When working together, they can detect objects in space with better clarity and at greater distances than any other current Earth-based observatories can
Examples of interferometry
-Keck I and Keck II are located 85 m apart from each
other.
-Very Large Telescope of the European Southern Observatory, located high in the Andean Mountains in
Chile. It is really four separate telescopes being used together.
What factors can interfere with star gazing?
Clouds, humidity (moisture in the air), and even high winds can interfere with star-gazing
What type of telescope is the Hubble telescope?
a reflecting telescope
What is the advantage of the Hubble telescope?
Clouds, humidity(moisture in the air), and even high winds do not affect the star gazing
What does the Hubble Space Telescope?
Orbiting about 600 km above Earth, the Hubble Space Telescope (a reflecting telescope) uses a series of mirrors to focus light from extremely distant objects.
goes to activities such as turning the telescope to focus on a new object of interest or switching data transmission modes
Hubble Space Telescope have discovered galaxies in parts of space (located in outerspace)
Each orbit that the Hubble makes around Earth takes about…….
95 min
Parts of a Hubble Space Telescope:
imaging electronics
solar panels
primary light-gathering mirror
Sun shield
