Humans are a naturally curious species. We’ve always looked up into the sky in astonishment, wondering what those shining dots really were.
Classical notions of space were pretty far-fetched. Some had stars pegged as candles, while others were convinced they were holes in the sky which the Gods peered through. Hell, the Greeks believed the Milky Way was literally a spilt glass of milk which slipped out of the hands of a clumsy god.
However, Aristotle, a Greek astronomer, finally brought some order to this mysterious discipline. He posited that the universe was spherical and finite, with the earth at its centre, and celestial bodies rotated around it.
While modern day theories disprove Aristotle’s notion of the earth being the centre of the universe, his insights were a step in the right direction.
Today, we have the accumulated knowledge and technology to put together more robust theories. Extremely sophisticated devices such as the Hubble Telescope have helped us understand the origin and nature of our Universe; astronomical conjectures have become concrete certainties. Indeed, no longer do we need to partake in mental exercises of space simulation.
What is The Hubble Telescope?
As astronomers began to understand more and more about our universe, they developed a singular goal. To see more, to see farther, and to see deeper.
This goal culminated in the launch of the Hubble Telescope in 1990. All of a sudden, we were able to see the universe in unprecedented detail.
The Hubble Telescope is a space-based telescope that orbits the earth, 353 miles above our planet’s surface. Named after the famous astronomer Edwin Hubble, this 13.2m long telescope has recorded some of the most detailed visible-light images ever, giving us an unparalleled view into space and time.
Hubble helps with space exploration. Having snapped hundreds of thousands of images and beamed them back to earth, this space telescope has shed light on many of the seemingly unsolvable mysteries of astronomy.
Among its many discoveries, Hubble helped ascertain the age of the universe and uncovered the existence of universe-expanding dark energy. What’s more, they helped realise the uniqueness of supermassive, red blackholes surrounded by an accretion disk. For the beginners out there, these are “Quasors”.
More regular sightings from the Hubble Telescope are the birth and death of stars, and enviable views of galaxies which exist billions of light years away.
So – I think NASA has provided the American Taxpayer a satisfactory return on investment. With US Citizens paying on average 2 cents per week to keep it running, I’d argue they’re getting their monies worth.
How Does the Hubble Telescope Work?
The most common misconception about telescopes is that they work by magnifying the objects before them. To the contrary, the genius of telescopes lie in their ability to capture more light than the human eye can handle.
The Hubble Telescope, which is a Cassegrain reflector, is no different. Light hits its main mirror, known as the primary mirror. From there, it is redirected to the secondary mirror, which focuses it through a hole in the primary mirror, en-route to a series of scientific instruments. The scientific instruments work together or independently – and the magic, the final image is provided, like an artist completing a masterpiece.
Each scientific instrument has a different interpretation of the Universe. The Advanced Camera for Surveys (ACS), for example, uses visible light to study the evolution of clusters of galaxies (among other things), while the Space Telescope Imaging Spectograph (STIS) hunts down black holes by focusing on ultraviolet, near-infrared, and visible light.
For all you eco-friendly types fretting about the unthinkable amount of energy the Hubble Telescope must require – fret not. Powered entirely by sunlight, Hubble’s solar arrays convert sunlight directly into electricity. It even has the foresight to store up electricity in its batteries for running when it finds itself in earth’s shadow.
What Differentiates the Hubble Telescope from Land-Based Ones?
Telescopes, since the dawn of their invention, have fallen foul to an earthly problem; the atmosphere. The quandary is twofold. Firstly, our atmosphere is hostile to some wavelengths of radiation like gamma and x-rays, as well as ultraviolet light. It actually partially blocks or absorbs these wavelengths. Because of this problem, observing a star from earth, is akin to reading a novel with missing pages.
Secondly, the earth’s atmosphere is riddled with shifting pockets of air, which distort the view of ground-based telescopes regardless of how well engineered and cutting-edge they are. Ever wondered why stars twinkle? This effect is caused by the same atmospheric distortion.
Placing a telescope in outer space is the best way to overcome these problems. In the case of Hubble, camping out 569km’s above the earth’s surface was deemed to be the best solution.
Major Findings from the Hubble Telescope
Ever wondered how old the universe is?
Prior to the deployment of the Hubble Telescope, scientist’s best guess was between 10 – 20 billion years. Now, to me this is a ridiculously large range. If someone asked me how old I was, and I replied, well I’m probably between the age of 6 and 99, it would probably be quite unhelpful. However, the Hubble helped narrow down their guesstimate to between 13 and 14 billion years.
Additionally, Hubble has given scientists a peek behind the curtain as to how galaxies are formed. By observing “toddler” galaxies, which were around when the universe was still young, scientists obtained invaluable insight into how galaxies develop.
Not Impressed yet? Hubble is a black hole bounty hunter. Considering that black holes suck in everything around them, including light, one would think them unobservable. No problem is too large for the world’s best-known space telescope.
I could go on. A mysterious force known as dark energy, which causes the universe to expand at an accelerating rate, was found by the Hubble Telescope. Better still, it found protoplanetary disks, which, because of their fertile mass of gas and dust, are birthing grounds for baby planets.
Check out the “Hubble Ultra Deep Field” if you’re interested in seeing the most distant galaxies ever recorded.