SKY GIANTS

Otago Daily Times, Issue 23002, 3 October 1936, Page 18

SKY GIANTS

ANTARES AND JUPITER UNIMAGINABLE DISTANCES

By W. D. A.

What is the biggest thing in the universe? According to the Astronomers of the Mount Wilson Observatory, which is equipped with some of the finest astronomical and mathematical instruments in the world, the universe to which our solar system belongs (the Galaxy) is 5,869,713,600,000,000,000 miles wide. In this sense “ universe ” means a great star system forming a kind of stellar island in the vast sea of space. It would ‘thus appear that the biggest single thing must be the greatest of the nebulae, though which this is we are at present unable to say, owing to the difficulty of ascertaining their distances from us. These nebulae, which appear in the sky as hazy patches of light, are vast masses of cosmic dust and light gases, out of which stars have been, and are being, evolved. Apart from these stupendous nebulae, the biggest single object in the universe, so far as we know, is the giant star Antares, which has been found to have a diameter of between 360,000,000 and 420,000,000 miles, as against our own sun’s diameter of only 866,000 miles. At the present time Antares can be seen in our evening sky any clear evening. It can easily be picked up as a prominent red star in the constellation of the Scorpion, which is one of those groups whose shapes readily suggest the object they are named after. It lies across the western sky, slightly to the south, between zenith and horizon. The form of this interesting constellation can be compared to a double interrogation mark. In this group of stars is the first magnitude star Antares, whose diameter is nearly 500 times that of our sun. It can easily be distinguished by its deep red colour. If our sun could be placed at the centre of Antares, not only the earth, but the planet Mars could revolve at their present distances and still be within this distant star. This, then, is the giant sun Antares, and close by, eight degrees to the north, will be seen the greatest planet of the solar system— Jupiter. Consequently, close together at this time can be seen the greatest star known to science and the largest planet of the solar system. The actual construction of the heavens still remains a supreme mystery. We cannot tell with any certainty whether the starry universe is of finite or of infinite extent, nor read the architectural plan which determines the positions and the motions of the stars. We must always remember that our view of the heavens is strangely composite. It is a table of records of all ages appearing simultaneously upon the background of unfathomable space. Written upon it we see every gradation of form, from nebula to star, and through all the phases of stellar luminosity to extinction. And in all probability the dark bodies, which we never see, far outnumber the myriads of luminous bodies. It is quite possible that dark stars form the majority of heavenly bodies and that space is tenanted by a host of undiscoverable star systems far outnumbering the myriads of luminaries which powerful present-day telescopes are revealing. The stars, even the nearest, are all at enormous distances. from us. Our sun, with his system of planets, etc., is but a speck in the ocean of space surrounding him. Unimaginable distances separate him even from his nearest neighbours, and he rolls on in apparent isolation in the universe known as the Milky Way, so immense is the void which surrounds us on every side.