Sight is the god gifted thing to all living creatures on the earth. Specially, we the Humans use it very smartly. Since childhood to adulthood we all can “see” throughout our lives and make a difference in it. But the human’s eye vision has also got some limitations as well. Like, we can’t see in darkness. But there are some birds, butterfly who can actually see what we can’t see.
It has been observed that since evolution man has cultivated his seeing power and has used it as an ultimate weapon to observe the things. The ancient man didn’t had smart watches look for time. Instead, he used to observe the motions of moon, sun, stars and used them as a clock to follow a routine. Like when sun enters the Mriga nakshatra ( Orion constellation), the rainy season used to commence.
As the human gets developed, his curiosity also gets increased about the nature, the universe! In the era of industrialization during 16th Century, world has seen many famous Scientists and Galileo was one of them. But my friends, let me tell you one fact that Galileo didn’t invented Telescope. In 1608, a glass trader Hans Lippershey made an instrument with two lenses fixed on ends of a tube and used it as a tool to look for the land areas, now that instrument we call it as Telescope! When Galileo came to know about it, he himself made a slightly bigger “instrument” and pointed towards night sky and he got wondered!! This became a turning point for the astronomy! Human’s vision got more & more wider and he started looking directly into the cosmos.
Thereafter, many scientists made bigger & bigger telescopes. But there was one difficulty, the earth’s atmosphere. Hence on 24 April 1990 Hubble space telescope was launched! Hubble saw what humans could not be able to see it from the earth! It saw many stars, birth & deaths of stars , so many planets, black holes etc. After serving science for more than 3 decades, Hubble has reached its limitations. Now we need a replacement or a successor to it.
This telescope’s name has been given to honour the work done by NASA’s 2nd chief Mr. James Webb. It’s easy to understand the Webb telescope we should do comparative analysis of it with Hubble space telescope.
1) The size of the Webb telescope is bigger than that of Hubble. If the Hubble is the size of a truck then Webb can fit into a standard Tennis court.
2) Mirror is the soul of the telescope. Bigger the mirror, greater the capacity of the telescope to cover the sky. Webb’s mirror is 2.5 the size of the Hubble. Webb’s mirror is of 6.5 meters in diameter. However Webb’s mirror is not the circular like traditional telescope, but it’s in the shape of a big Hexagon. This big hexagon has been divided into 18 equal hexagons. But the most interesting fact is here. It’s mirror is completely covered by the thin insulation of PURE GOLD!!! This will increase the reflectivity of telescope.
3) Webb will be sent into space in single piece however this huge telescope will be sent folded in the rocket and after reaching the space, it will slowly unfold like an Origami craft.
4) The main point is the “WAVELENGTH”. All of you must have seen the Rainbow. We can see the all 7 colurs in it. However, we can’t see the entire “spectrum” of the light and that light is called as Electro-magnetic spectrum! Our eyes can “see” only a small part of this Electro-magnetic spectrum & we call it as light. If we consider this spectrum as a scale, then starting from lesser to greatest lengths, we, we have Gamma, X-rays, Ultra violet, visible, infrared, microwave, radio waves. Human eyes can see only the visible rays & the same is with the Hubble telescope. However Webb can see in infrared region also.
Now the question arises that Why only Infra-red??
I will try to explain in 3 aspects:
1) The hottest star in the space is of blue colour & the coolest star is in red colour. (This is the exactly opposite of our understanding of hot & cool). Oldest or primordial stars are coolest stars and therefore they emit energy in infrared rays. Hence Webb will be very much useful to detect such older & cooler stars in the universe.
2) If there is dust in the atmosphere then we can’t have clear sky to look for stars. But infrared vision of the Webb can pierce through the clouds of dust and see beyond it!
3) In 1919, American Astronomer Edwin Hubble discovered that all galaxies are moving away from each other, due to expansion of the universe. This is called cosmological red shift and galaxies emits in infrared wavelengths. That’s why infrared vision of Webb will be very much useful.
Therefore if we look in broader sense, then we can understand the mysterious black holes, birth of the universe, dark matter etc.
The Webb telescope will be situated in a very special place in space and the speciality of that space is of we put anything there then that thing will remain there stationary like the pole star! And this point in space is called as LAGRENGIAN POINT! Our earth – sun system has 5 such points & Webb will be placed on L5 point.
The performance of any system depends upon the devices it’s using. Webb has the most advanced cameras, spectrometers on its board. Nir CAM, NirSPEC, NiRIS, MiRi etc. are the short forms of the devices. How the universe born?? Is there life on other planets?? Are we alone in the universe?? Etc. Webb will try to find the answers for such questions.
On the Christmas eve, 25th December 2021 the Webb telescope was launched into space & began her journey to unravel the space mysteries!!!🔭✨
©️ Ambarish Pawar