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Hubble Telescope or HST

Last updated date: 29th Feb 2024
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What is Hubble Telescope ?

The Hubble telescope is a space telescope. It is one of the largest and most versatile vital research tools, significant to public relations. It has proved to be a boon for astronomy. It is named after astronomer Edwin Hubble who studied distant galaxies and is NASA's one of the great observatories. It was launched into a lower orbit of Earth in 1990. Let us read ahead to learn more about this interesting piece of equipment and its function.

Hubble Space Telescope

Hubble Space Telescope

Hubble's History

NASA's Hubble space telescope has been looking out into the universe for 30 years. In 1946, Lyman Spitzer wrote a paper about the idea of a 'large space telescope'. The first group started work on 'large space telescope' in 1974. It was launched on April 24, 1990 and was deployed on April 25. It was a joint project between NASA and the European Space Agency.

Hubble's Location

As Earth's atmosphere blocks some wavelengths and blurs Earth's telescopic images, Hubble is in orbit beyond our atmosphere to get a clearer picture than what Earth's telescope can capture. Hubble has a unique position above Earth's atmosphere which gives it incredible clarity. Hubble orbits the Earth about 340 miles above its surface and an inclination of 28.5°, where it completes 15 orbits per day, approximately one revolution every 95 minutes. Hubble has orbited 175,200 times in its 30 years of operation. As it circles above the atmosphere, it can view astronomical objects across a wider range of electromagnetic spectrum.

Working of Hubble Telescope

Hubble contains 2 mirrors-

  • Primary

  • Secondary

It is a reflecting telescope. Light hits the primary mirror and reflects to the secondary. The secondary reflects the light back through a hole in the primary, where it enters in Hubble's instruments for final focus before it hits their detectors. These instruments can detect and record three types of light: visible, ultraviolet, and infrared. Primary mirror (2.4 m in diameter) collects an immense amount of light. The space telescope can distinguish astronomical objects with an angular diameter of 0.05 arcsecond.

High resolution enables Hubble to locate such objects as dust disks around stars or the glowing nuclei of distant galaxies. It can see objects 13.4 billion light years away from Earth and revealed that the universe is about 13.8 billion years ago.

Instruments of Hubble

Instruments of Hubble

Solved Questions

1. How is Hubble different from the telescopes on Earth?

Ans: Hubble orbits above Earth's atmosphere which gives it a better view of the universe than telescopes at ground level.

2. Which types of wavelengths are detected by the Hubble telescope?

Ans: Hubble detects visible, near- infrared, and ultraviolet light.

3. Where is the hubble telescope now?

Ans: The Hubble telescope is currently located 535 km above the Earth surfaces.


The Hubble telescope is the first astronomical observatory to be placed into Earth's orbit which can record images in wavelength from ultraviolet to near infrared. It helped determine that the universe wasn't just expanding, but that the expansion was accelerating. It was a major turning point in science as it has changed humans' understanding of astronomy, led to important discoveries and many new technologies. It is designed to take high resolution pictures and accurate spectra to form sharper images than from the ground.

Picture of Black Hole Taken by Hubble

Picture of Black Hole Taken by Hubble

FAQs on Hubble Telescope or HST

1. What are the features of images taken by Hubble?

Hubble takes grayscale images. The colours in Hubble's images show chemical elements and other features that can't be seen by the human eye.

2. Has Hubble taken a picture of the Earth?

Hubble can't take images of the Earth because it is revolving too fast for the camera's exposure time.

3. Which instruments are on Hubble?

Hubble has 5 scientific instruments which are cameras and spectrographs. Hubble's main camera is the wide field camera 3.

4. What is the size of Hubble's telescope?

Its size is about a large school bus.

5. What are some of the important pieces of information given by Hubble?

It has been calculated that the universe is 13.8 million (approx) years old. Hubble also informed us that black holes are at the centre of almost every galaxy.