What is a Telescope? How good are Modern Telescopes?

Telescope is an optical instrument designed to magnify and observe distant objects by collecting and focusing light. Check here Components and Types of Telescopes in detail.

Table of Contents

Modern telescopes, whether on Earth or in space, help us explore the universe by collecting and focusing light from distant stars and galaxies. They act like a window into the cosmos, allowing astronomers to uncover its wonders and reminding us of the joy of discovery and our place in the universe.

About Telescopes

It is an instrument that uses lenses and mirrors to collect and focus light to observe distant objects in space.
They use lenses or mirrors to bend light rays and make distant objects appear close.
They are an essential tool for astronomers to study the universe by collecting and analysing radiation from celestial objects.

Aperture:
- Itrefers to the opening that collects light.
- A larger aperture allows more light to be gathered, creating clearer and more detailed images.

Types of Telescopes

Refracting Telescope:
- Uses lenses to gather and focus light.
- The first telescopes, invented by Hans Lippershey and improved by Galileo, were refractors.
- These are known for sharp images but can suffer from chromatic aberration (color distortion).
Reflecting Telescope:
- Uses mirrors instead of lenses to collect light.
- Invented by Isaac Newton to overcome the issues of chromatic aberration.
- Most large telescopes used in observatories today are reflectors.
Catadioptric Telescope:
- Combines lenses and mirrors to form the image.
- These telescopes aim to reduce the limitations of both refractors and reflectors, offering a more compact design.

How Telescopes Work?

Light Collection: Telescopes collect light from distant objects using either a lens (refracting telescope) or a mirror (reflecting telescope).
Magnification: The light is then magnified using eyepieces, allowing the observer to see faraway objects in greater detail.
Resolution: A telescope’s ability to resolve fine detail depends on its aperture (the diameter of its primary lens or mirror). Larger apertures collect more light and provide clearer, more detailed images.

Famous Telescopes

Hubble Space Telescope: A space-based telescope that has provided some of the most detailed images of distant galaxies and nebulae.
James Webb Space Telescope: Launched in 2021, this is designed to study the universe’s early formation and offers infrared imaging capabilities.

Why Telescopes are set up on Mountains?

Mountain observatories provide clearer skies due to reduced atmospheric distortion.
Space telescopes, above the atmosphere, deliver even clearer views.
- g. Hubble Telescope

Advanced Telescopes around the World

Large binocular Telescope:
- It has two 8.4-m-wide mirrors and an effective combined aperture of 11.9 m.
- Location: Mount Graham International Observatory in Arizona, USA.
Extremely Large Telescope (ELT):
- It is under construction atop the Cerro Armazones in the Atacama Desert in Chile, as part of the European Southern Observatory.
- It is expected to be completed by 2028.
- The ELT’s light-gathering power will exceed that of any telescope till date, It can distinguish two lights kept 30 cm apart from 12,000 km.
Subaru Telescope:
- It is an 8.2-m-wide Japanese telescope.
- Location: Mauna Kea Observatory in Hawaii.