By Andrew James


Astronomy surpasses every other science in the sublimity
and grandeur of the objects in which it contemplates.
The magnificent appearance of the Celestial Bodies, the
regularity and harmony of their motions, combined with
the various phenomena they display, strike us with
astonishment and profound admiration!

The British Celestial Atlas, vi. (1830)
G. Rubie

ASTRONOMY can be summarised as the study of all objects and their structures lying beyond the confines of the Earth. The oldest and perhaps the most fascinating of all the sciences, and it is different than them as sky is accessible to everybody. Originally, the science of astronomy was about understanding the movements and positions of all celestial bodies. Today, with the introduction of topics relating to the sciences of both biology, physics and chemistry, means that astronomy now encompasses much wider courses of study. Since the mid-19th century, the adopted method of investigation into astronomy subdivides into; Astrophysics, applying to the basic principals governing all bodies from planets, stars to galaxies, and Cosmology, applying to the understanding nature of the whole universe — accounting for all atomic matter, the stars and galaxies; and towards details of the universe — its origin, evolution and eventual demise. In the modern sense, the science of astronomy generally encompasses both astrophysics and cosmology.

For many of us, astronomy great interest, probably has some real psychology basis. The darkness at night awakens primitive instinct deep within us, like children who often fear the night, which is sometimes manifest by imagining fictitious unseen creatures. We likely feeling this from the transition day into night, producing effects like the lowering of the bodys temperature or the loss of colour vision. This makes us seemingly vulnerable and insecure — feelings which are both dark and remorse. These fears haunt us, as they may also reminded us of the unknown void of the subconscious that we daily explore in our nightly sleep.

Yet the darkened night sky is gloriously blanketed with stars, that each endowing us with the true sense of company. Those many tiny points of illumination, continue to ignite some inner flame within us. Once they have touched you, and you will have come to know their nightly positions, then their daily appearance becomes more akin to visits from old and familiar friends.

Over several nights one can see the changing phases of the Moon or perhaps discern the slow movements of the planets among the background stars.

Even the slow and steady rotation of the sky is of particular interest. New stars will appear to rise from the eastern horizon, while more familiar ones lay down to rest and disappear in the west. We also discern that the star patterns, or constellations, change as the weeks go by. Stars rising in the east, say at 10pm, are found to rise almost half-an-hour earlier as each week progresses. At the same instant, different stars closer to the western horizon will gradually disappear. As the seasons change, so the whole aspects of the sky changes. Those constellations once visible in the western evening sky disappear altogether, only to be replaced by others from the east. Summer in the southern hemisphere finds the constellation Orion the Hunter dominating the sky, while during winter the constellation of Scorpius shines gloriously overhead. Eventually after one year has passed, the sky returns to its original places, again showing us the same familiar constellations of that season.

Moving to the southern horizon, other constellations like the Southern Cross do something different. These stars never set below the horizon and so can be seen throughout the year. If we could see the stars during the daytime, we would see the Southern Cross, the constellation known as Crux, travels in nearly one complete circle in enty-four hours. As the seasons pass in places like Sydney, Australia, at 10pm during summer finds the Southern Cross fairly close to the southeastern horizon. By autumn at the same time, we see the Cross hanging high up and slightly south of zenith. Similarly, winter finds the Cross facing southwest, while during spring it will be pointing downward towards due south. If we were in the northern hemisphere, similar observations occur, except now we have to face the north and look at the mirror constellation named Cassiopeia, sometimes nicknamed the chair. Due to their positions in the sky, neither the Cassiopeia can be seen in the southern sky nor the Southern Cross from the northern one.

On dark nights, away from the city lights, we can see dividing the sky into two hemispheres the pearly white light known as the Milky Way. City dwellers often miss seeing the Milky Way, but in the country, the sky blazes splendidly with its beautiful pearly light. Looking with the smallest of telescopes reveals that its faint unresolved light is really seemingly uncountable multitudes of stars. These stars are in our own Galaxy. More humbling is to think that our own Sun is only the tiniest part in these myriads of stars, whose total number of stars exceed four-hundred-billion. The poet Milton aptly describes this in the classic Paradise Lost”:–

…as stars to thee appear
Seen in a galaxy, that Milky Way
Which nightly as a circling zone thou seest,
Powderd with stars.”

Our entire lives are also all in-tune” with the skies. We set our daily habits to the rising and setting of the sun, and often unbeknown to us, have our internal biological clocks and sleeping habits set to its daily movements. The moon controls many human an many non-human reproductive and biological mechanisms. A womans monthly cycle, for example, exactly mimics the lunar cycle, while once each Full Moon, some fish species and coral will spawn simultaneously together in the sea. Similarly as the sun is about to rise, electrical activity increases in all our bodies, telling our brain of the eminent sunrise and to begin our daily activities. Another is the honey bees, which use the ultra-violet polarised light of the sun to find their orientation and the direction of the hive. Even some birds are thought to during the night to use the bright stars to navigate across the sea or land to travel to their yearly migratory destinations.

Our own moon, and lesser in extent, the sun, also influence the tides. This twice-daily cycle is completed once every twelve and half hours or so. The feeding habits of fish in the sea know of the tidal cycle, and use this to take advantage of the minions they feed for sustenance.

Astronomy, in a different way, poses many questions about our own role and place in the Universe. These have profound implications on the human mind and our personal existence. For some it extends to a strong religious faith, firm beliefs or through dogma, and may be based on a priori − either as scientific or perhaps some philosophic view or perspective. Many of these questions have greatly perplexed many great thinkers in the past. This will likely continue in the future. We find most difficult, for example, that the vast astronomical distances or the true size or mass of most astronomical objects to be absolutely astonishing. Our feeble minds begin to show some weakness, for we cannot grasp such immensities.

Harder for each of us is to realize that we are both looking into space and observing backwards in time. Reasons for this is that light travels no faster than an absolute finite speed of three-hundred-thousand kilometres every second. The distance of three-hundred-thousand kilometres travelled is equal to about seven-and-a-half times around the Earths circumference. Even at this speed, it takes sunlight about eight minutes to cross the distance of one-hundred-and-fifty million kilometres between the Sun and the Earth. To the nearest star Alpha Centauri, even at this colossal velocity, it takes over 4.3 years to reach our eyes. If something were to happen to this star right now, we will only know about it 4.3 years after the event sometime in our future. So if any event happens with any other astronomical object, knowing about it will only dependant on how far the object is away in light-years from the Earth.

A plentiful abundance exists of true wonders in our Universe. To see them requires only small telescopes or binoculars. Examples of these commonly existing types of these diverse astronomical objects include;

Double and multiple stars
Stars connected physically by gravitation, orbiting each other in tens to thousands of years.

Variable stars
Stars that vary in brightness over minutes, years or sometimes centuries.

Open star clusters and Globular star clusters
Stellar groups containing many hundreds to several millions of stars within several tens or hundreds of light-years.

Huge gas clouds composed of vast quantities of Hydrogen, Helium and dusty material that are manufacturing and nurturing brand-new stars.

Planetary nebulae
Illumination of gas ejections via superwinds from old dying stars.

Biggest single collections of objects in the Universe containing many billions of suns, whose feeble light travels through space for perhaps millions or even billions of years.

It is important to note, once you start exploring the sky, that each amateur stargazer has unique perspectives of their world. He or she has seen vast distances, and has travelled to far different places than the Earth, and has even seen into the distant past.


Last Update : 5th December 2014

Southern Astronomical Delights © (2014)

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