Non-Optical Telescopes and Their Functions

Why are non-optical telescopes essential for astronomical observations?

• They are less expensive to build than optical telescopes.

• Stellar objects emit radiation across the entire electromagnetic spectrum, and optical telescopes only detect visible light.

• They can operate in all weather conditions, unlike optical telescopes.

• Non-optical radiation travels faster through space, allowing for quicker observations.

What is a significant advantage of radio telescopes over optical telescopes in terms of their primary dish construction?

• Radio telescope dishes must be made of highly polished glass for precise reflection.

• Radio telescope dishes can be made of wire mesh, which is cheaper and lighter, because radio waves have longer wavelengths.

• Optical telescopes require larger primary mirrors, making them more difficult to construct.

• The primary dish of a radio telescope does not need to reflect waves to a focal point.

What is a primary disadvantage of a single radio telescope compared to an optical telescope regarding image clarity?

• Radio telescopes are more susceptible to atmospheric interference.

• Radio telescopes have a very poor resolving power due to the long wavelengths of radio waves.

• They cannot be used during the day, limiting observation time.

• The parabolic dish of a radio telescope suffers from significant spherical aberration.

How do astronomers overcome the poor resolving power of individual radio telescopes?

• By using larger individual parabolic dishes, often made of glass.

• By placing them in orbit to avoid atmospheric interference.

• By linking multiple radio telescopes together to form a single, larger effective telescope.

• By using advanced digital signal processing to enhance the image resolution.

What is the primary function of a preamplifier in a radio telescope system?

• To convert radio waves into visible light.

• To reflect radio waves to the aerial.

• To amplify weak radio signals without adding significant noise.

• To transmit information for analysis.

Why are infrared telescopes often placed in space or in high, dry locations on Earth?

• To avoid interference from visible light.

• To minimize the absorption of infrared radiation by water vapor in the atmosphere.

• To reduce the need for a primary concave mirror.

• To allow for easier maintenance and coolant replenishment.

Why is it challenging to manufacture ultraviolet (UV) telescopes?

• UV radiation has a longer wavelength than visible light, making mirrors less effective.

• UV radiation is easily absorbed by water vapor, requiring specialized materials.

• UV radiation has a shorter wavelength than visible light, requiring mirrors to be more parabolic and precise.

• UV telescopes require extremely low temperatures to operate efficiently.

How do X-ray telescopes typically focus incoming X-rays to a focal point?

• They use a single, highly curved parabolic mirror.

• They employ a series of nested mirrors that slightly graze the X-rays.

• They absorb X-rays and then re-emit them as visible light.

• They use a preamplifier to amplify the X-ray signals.

How are gamma rays from space detected by ground-based telescopes, despite being absorbed by Earth's atmosphere?

• They are directly detected by specialized ground-based telescopes.

• The particles and radiation produced when gamma rays hit the upper atmosphere are detected.

• They are converted into visible light by atmospheric particles, which are then observed.

• Ground-based telescopes use advanced filters to block atmospheric interference and detect gamma rays.

What is a primary reason for placing modern non-optical telescopes in space?

• To avoid the high cost of ground-based construction.

• To prevent damage from terrestrial weather conditions.

• To overcome the absorption of electromagnetic waves by Earth's atmosphere.

• To allow for easier maintenance and upgrades.