Space telescopes have long been around us now. It’s true that with our ordinary reflective and refractive telescopes that used mirrors and lenses, we could never study astronomy. However, space telescopes have really helped us through the way. One such example is a Hubble Space Telescope.
Advantages of Space Telescopes
- Space-based telescopes provide a better and more detailed view of the Space.
- They can detect and record frequencies and wavelengths in different regions of the EMR spectrum.
- Space-based telescopes do not interfere with the Earth’s atmosphere.
Disadvantages of Space Telescopes
- They are expensive and challenging to build and launch.
- Often require a spacecraft to launch them somewhere up in the orbit
- The maintenance and replacement of Space telescopes are almost impossible.
History of Hubble Space Telescope
The year 1990 has the honor of launching the Hubble Space Telescope into orbit around Earth. Its name is after a famous Astro-scientist Edwin Hubble whose contributions to the cause are remarkable.
It is a “reflector type” telescope. Thus, it uses curved mirrors as its optics to reflect light to have a clear view of the image.
Construction of the Hubble Space Telescope
The telescope has a primary reflecting mirror 94.5 inches or 2.4 meters in diameter. It is packed with everything that could give astronomers the most detailed view of the Universe. It works perfectly in visible, infrared, and ultraviolet regions of the electromagnetic spectrum.
If the Earth’s atmosphere does not block its view, it can present even the minor astronomical details that we have never seen before.
Light Collector of HST
HST – or Hubble Space Telescope uses a glass mirror that is coated with a layer of aluminum.
Hubble Space Telescope Observable Spectrum
HST is able to observe the lights in infrared (IR), visible, and ultraviolet (UV) region of the spectrum.
Distance from the Earth
The Hubble Space Telescope is at a distance of 600 kilometers from Earth’s surface and is orbiting above it.
Design and Working of the Hubble Space Telescope
Parts of the Telescope
The Hubble consists of the following major parts:
- Concave Primary Mirror
- Convex Secondary Mirror
- Other Instruments
Working of Hubble Space Telescope
First, as the light enters the telescope, it touches the Hubble Space Telescope’s primary concave mirror, which reflects it off to the secondary convex mirror. The convex mirror reflects back and passes through a hole in the center of the primary mirror. This light then reaches and focal point and goes to the other instruments for detection and analysis.
Such designs are the signature styles of Cassegrain Telescopes – naming after the person who designed them.
Primary Purpose of the Hubble Telescope
The Hubble Space Telescope’s main purpose was to determine how long the Universe has been in place and when the galaxies form. It was unbelievable in the beginning how the Hubble was able to provide extraordinary details about many stars like Sun that spend their lives as planetary nebulae.
Challenges in Space Observation by Using HST
After launching Hubble, the astronomers were met with an unexpected and unforeseen circumstance. It was something that had haunted the astronomers for centuries, but they were not expecting it here, at least. And it was nothing, but “spherical aberration” again.
Fortunately, during Hubble’s designing, a unanimous decision brought about the putting together of Hubble with interchangeable parts. Hence, the astronauts went into Space and figured out the problem.
Soon enough, they were able to find out the primary mirror of the Hubble Space Telescope had a problem with it. The curve was a bit (approximately depth of 50 times less than the human hair thickness) flat. Hence, the angle was corrected. This incident has the honor of being the first NASA mission in which they sent the astronauts physically for the repair and improvement of telescopes.
Fixing of the Hubble Space Telescope in the Space
After a period of some good three years, astronauts were finally able to install small mirrors in front of the original optics. In this way, the Hubble started working just fine. There was no more blurriness in the images that Hubble gave out. It’s just like putting a pair of glasses on the telescope, impressive!
Ever since the repairing of the Hubble, the scientist and astronauts frequently pay visits to it. They make sure that all the Hubble Telescope parts are working correctly – and in case if there is a glitch, they fix it there and then. Moreover, they are continually working to derive out new and better parts for the telescope.
There is no denying in it that whenever the astronauts replace a part in Hubble, the results tend to get significantly better and surprising than the older counterparts.
Contributions of Hubble Space Telescope in Astronomy
It has been beneficial throughout the journey of space-studying and has really helped the astronomers. Most of the initial knowledge of the Universe came down from the Hubble space telescopes. Unlike the other telescopes that do not get any repairing once they are in Space, Hubble is quite unprecedented and remarkable. Hubble has been very constructive in answering a certain question like how rapidly the Universe expands and how long it has been doing so.
The Hubble also gave the evidence of giant black holes just in the middle of all neighboring galaxies. Moreover, it has been very fruitful in tracing down the exoplanets, which could help in fostering human life on them. The telescope studied the supernovae and contributed to developing a theory about “dark energy” – that is causing the Universe to expand and increase at a very fast rate.
As mentioned above, the story about Hubble’s launching and working indicates how critical it is to be an astronomer. Even a slight change in any of the optics can actually put you in hot waters. Like a curve of about 10th, part of a millimeter was going to derail all the results of the Hubble telescope. It produces the images in different shades of black and white. Moreover, many people consider the James Webb Space telescope as a successor of the Hubble Space Telescope. It is said that with its successive counterparts, the astronomers would be able to see a better and much clearer view of the Universe – that’s more deeper into the sky.