May 3, 2020
By: Haris Ahmad[1]
The Hubble telescope was launched by NASA (National Aeronautics and Space Administration)
and ESA (European Space Agency) on April 24, 1990. Space Shuttle Discovery
launched it into orbit. The Hubble telescope orbits approximately 547 km above
Earth. It travels 5 miles per second and is solar-powered; hence, it gets
energy from the Sun. Hubble takes clear and sharp images of the celestial
bodies in space e.g. planets, stars, galaxies, and nebulae. It can take images
of celestial bodies, which are billions of light-years away from us. In this blog, I will explain that even though Hubble
made many astonishing discoveries about celestial bodies many light-years away,
it still has limited sight. This
doesn’t mean that it was useless. It made discoveries which totally changed our
perception of the universe. One of the greatest images this telescope took was the Hubble deep
field, which is an image of a small region in the Ursa Major constellation.
All the
colorful dots you see are individual galaxies and this makes you wonder just
how big this universe is and how small we are. These galaxies may seem a lot but they
are just the ones from a tiny spot we can see in the sky. You can even find
more Hubble deep field images on NASA and ESA websites. This wasn’t the only
astonishing image; it took many other images of planets, stars, nebulae and galaxies.
Therefore,
only the light from the range of wavelengths that the telescope’s instruments
can observe is captured. Hence, the visible light that has a longer wavelength
than that of Hubble can see is not visible to it. This is the main reason why
Hubble can’t see the galaxies of the early universe because the wavelengths of
their light are much longer. Moreover, another factor that adds to this
disability is the expansion of the Universe. Many of you may know the Doppler effect. If you don't know about it then I'll explain it with an example. When an ambulance is blowing its siren close to you, you can hear the sound very loudly because the pitch of the sound is high due to the shorter wavelengths of sound; however, when the ambulance goes further away from you, the pitch of the sound gets lower and the wavelengths are longer and hence, you hear the sound slower. The same effect happens with light when the universe expands. When the universe expands, the
wavelengths from distant objects also expand and due to this, Hubble can’t
capture these longer wavelengths because they are out of its reach. However, we shouldn’t just give up. Space scientists
are filling this pothole by creating another telescope that will see what Hubble
could not and that telescope is the James Webb Telescope.
The making of this telescope is the largest, most
expensive, and the most challenging space-engineering project the humans have
ever attempted. NASA has been working on this project for 30 years and it is called, The James Webb Telescope. The James
Webb telescope can take images in more detail and higher distances than the
Hubble telescope and can see objects that have details about the origin of the
universe. This telescope will help us understand how the universe started and
how it formed. It would uncover the forces of the universe and the evolution of
how many objects formed in the universe and how. Not only will this telescope help us
see the past of this universe, but it will also help us predict the fate of
many of the galaxies, stars, etc. This telescope has the ability to capture
infra-red the light that ultimately helps it significantly in finding objects
much farther than the Hubble could see. The main problem though is that the Sun
also emits infra-red light so, how do we keep the infra-red light from the Sun
away? Well, this telescope has a sun shield which blocks all the light from
the Sun from reaching the telescope’s camera. Scientists still have a lot of
problems to tackle before we launch this but, one problem is what we all have
to pray to end well. That problem is the launch. Now, we know that rocket
launches are extremely hard and have a high chance of failure. Therefore, we
have to launch this telescope perfectly into space or else, a lot of money,
effort, and time will be wasted. This telescope will be launched into orbit at a
very far distance, at a point called the Second Lagrangian point. This point in
orbit is 1.5 million km away from the Earth though it is still in the zone of
orbiting the Earth. The advantage of this orbit is that it would clear out a
huge space for the telescope to see.
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