As we look at the night sky , think of ourself as a passenger on a Space ship . Actually we are . Our Earth is a place traveling rapidly through Space. All around the earth is the universe . It is depend our self to study & enjoy , as far as our eyes can see . As we know that what is our Place in our Universe , There is so many Galaxy , Stars, Constellation etc. which is found in Universe . as compare to other our Earth is very Small.
The Bold words of California Scientist Said" FIRST WE THROW A LITTLE SOME THING INTO SKIES, THEN A LITTLE MORE ,THEN A SHIPLOAD OF INSTRUMETS .
Some time Scientist Believe a Rocketship Loaded with instrument s will be sent to the moon within 50 years . No one knows Exactly how much we could learn from instruments we might send to the moon . But they would , no doubt , add to our knowledge of astronomy , the science which studies Space & the things it contains.
To Begin we need our eyes and good , clear , dark night . If we have a small Telescope or a pair of a good field Glasses , so much the better ...
AS we Understood in Following Chapters:
*Milkyway:-
All the Stars we can see as Separate points of light are within our own Galaxy . Our Galaxy is known as The MILKYWAY galaxy . If we could view it from some place , say 900,000 lightyears away, it would look very much the way the galaxy Andromeda looks from th ou Earth.
How many stars we can think as see on a Single night Under the best seeing Conditions....?
The answer can may Surprise . ti is only about 2,000 . Of the Thousand of millions of stars in the Galaxy , Only 5,000 or 6,000 are Bright enough and near enough to seen Without Telescope or field glasses. At least half of these are hidden from our view , in the part of the sky at present below horizon . The horizon is the line in the distance where the earth and sky seem to come together .
If we wait for few an Hours , the rotation of the earth will bring into view the stars now just below the Eastern horizon . The rotation of earth is from the west toward east . Therefore ,as the hour of night pass , the stars in the east appear to rise .Those in the western part of the sky appear to set as the night goes by .
Galaxy Star that belong Together:-
Even before Galileo's invention of the Telscope , Sky Watchers noticed that in addition to several thousand sharp points of light they called stars there were a few hazy , blurred patches in the night time sky to whichthey gave name of NEBULAE (clouds) . Early Telescopes revealed thousands more of these , and modern telescope s have shown that many of these nebulae are really systems families containing millions of Star . Today we call these system as Galaxies , Although galaxies are millions of Light years apart , our giant telescope indicates that space contains atleast 100,000,000 Galaxies , each probly including many millions of stars ! The graet 18th century Astronomer Sir William Herschel called these galaxies "Island Universes" to emphasize the vast emptiness of space between them .
The galaxy to which the earth belongs is the Milky wy . In this galaxy Our Sun is also one star among many billions of stars , and its nearest neighbor is Proxima Centuri . Every star that we can see with naked eye is part of our Milky way . Astronomers think that our galaxy is shaped like a disk a thin Watch ; that its diameter is about 1000,000 lightyears & its greatest thickness is about 10,000 lightyears; and that the sun is about two - thirds of the way from the galaxy's center to its edge. When we look along the plane of the " Watch " we see so many stars that the sky appears "milky " . when we look through the thickness of the watch , we see fewer stas in that part of sky . The entire Galaxy rotates in one direction , but its Stars may move at different speeds and in different directions .
The Nearest Galaxy Outside the Milkyway is the one Faintly visible to the naked eye as the famous great spiral in the Constellation Andromeda . This galaxy is estimated to be about 800,000light - years away. Next to our own Milky Way , it seems to e the Largest Galaxy often taken from thier Mythologies .