Introduction to Space Based Telescopes and Its Types

Space-Based Telescopes

Introduction:

A telescope having small lenses can zoom into the stars and other objects in the sky.

We are unable to view a distant object clearly because the object does not occupy much room on our eye’s screen (retina).

Our vision is limited when we look at objects. Our eyes can only see clearly up to a certain distance. We must use cameras, magnifying glasses, or telescopes to see an object properly.

We will need considerably larger eyes to gather enough brightness and light to see a more detailed image of something at a distance. If we want to see the image more clearly, we then need to magnify it.

Explanation:

The Main Parts of a Telescope:

1. The first component is an objective lens; it collects a lot of light from a far-off object in the distance and brings that light and the image to focus.
2. The bright light will then be magnified by an eyepiece lens, expanding outward, which can be seen clearly with our own eyes.

The Main Principle of a Telescope:

The basic concept is to gather a lot of light to create a bright image within the telescope and then magnify (enlarge) that bright image so that it occupies a large portion of your retina.

The Main Characteristics of a Telescope:

• Its ability to collect light: The diameter of the lens or mirror and the aperture used to gather light determine how well a telescope can collect light.
• Its ability to magnify a picture: The combination of lenses the telescope uses determines its magnification, or capacity to magnify a picture.

Mainly Telescopes are of Two Types:

Refracting Telescope:

Galileo created the first telescope in 1608. His telescope made faraway objects appear closer and larger by using two lenses. Refracting telescopes, sometimes known as refractors, are telescopes that use lenses to bend light.

The first telescopes were refractors. Refractors are still widely used by amateur astronomers today. Our solar system may be seen in detail with a refractor. Two examples of such details are the craters on the Moon’s surface and the rings of Saturn.

Reflecting Telescope:

Sir Isaac Newton created a different type of telescope around 1670. Instead of using lenses to focus light, Newton’s telescope utilized curved mirrors. Reflecting telescopes or reflectors are the name for this kind of telescope.

In comparison to a refractor telescope, which relies on a lens to gather light, reflecting telescopes employ mirrors to do so. The glass lenses in a refractor telescope are significantly heavier than the mirrors in a reflecting telescope.

Making mirrors with exact precision is far simpler than making glass lenses with exact precision. Because of this, reflectors may be built in bigger sizes than refractors. More light can be collected by larger telescopes. This enables them to study fainter or farther away items.

Reflectors are the largest optical telescopes now in use. Mirrors and lenses can both be used to make telescopes.

Electromagnetic Waves:

The space is almost empty or a vacuum. Different types of waves, which are known as electromagnetic waves, carry energy from space to the Earth.

Electromagnetic waves (light waves) are non-mechanical waves; they do not require any medium to travel. They can even travel through a vacuum. Electromagnetic waves do not require matter to transfer energy.

Except for visible light, the other electromagnetic waves that object in the universe emit that we can’t see with our eyes include radio waves, infrared waves, and X-rays. All these waves have energy (frequencies) that rise with decreasing wavelengths and move through space at the speed of light.

Astronomers use various telescopes to observe the various waves generated by space objects. Images of the Crab Nebula (the remains of an exploded star) taken by several telescopes, including optical (visible light), radio, infrared, and X-ray, are displayed in Figure.

Radio Telescope:

A radio telescope functions as a very powerful receiver that detects radio waves from space. These telescopes are pointed at an object, such as a star, and tuned so that it receives waves at the right frequency. A computer analyses the data and creates a picture of the radio wave’s origin.

Radio telescopes are used by astronomers to map planet surfaces, picture stars and galaxies, and determine the chemical makeup of objects.

Infrared Telescope:

Infrared waves are examined by another kind of telescope. Infrared telescopes are frequently mounted on satellites that orbit above Earth since this type of wave is primarily absorbed by the planet’s atmosphere.

The Infrared Astronomical Satellite (IRAS) was launched to scan the entire sky at infrared wavelengths in 1983. It uncovered a brand-new comet, proof of a different solar system, and a brand-new kind of galaxy.

X-Ray Telescope:

High-energy radiation from space can be captured using X-ray telescopes. X-ray telescopes are always mounted on satellites since these waves cannot pass through our atmosphere.

NASA’s Chandra X-ray Observatory, one of the most potent, was launched in 1999 on the space shuttle Columbia. Its objective is to study the X-rays that the universe’s high-energy objects, such as exploding stars, emit.

Space Based Telescopes:

One major issue that hampers any telescope on Earth is the requirement that incoming light passes through the atmosphere. Some radiation wavelengths are blocked by this. Additionally, light is distorted by atmospheric motion. This is evident when gazing at stars in the night sky; they twinkle.

Numerous observatories are situated at the top of tall mountains. There is less atmospheric interference since there is less air above the telescope. Since they orbit outside of the atmosphere, space telescopes sidestep these issues. The most well-known space telescope is the Hubble Space Telescope.

The Hubble Space Telescope:

The Hubble Space Telescope (or HST), named after American astronomer Edwin Hubble (1889 to 1953), is a satellite that orbits Earth at the height of 600 km above the Earth’s surface. This powerful telescope, placed out of reach of “light pollution,” sends images from deep space to computers back on Earth.

A NASA image captured by the HST is shown in the figure. Most of the objects in the image are not stars—which appear to have “spikes”—but galaxies, most of them billions of light years away!