Astronomy

Astronomy is the oldest and most fascinating science. Since ancient times, people have tried to understand the universe and the earth’s position in it. It may have begun in superstition with attempts to foretell the future of individuals. But it has gradually explained the marvels of the heavens. About 4000 B.C., the Egyptians developed a Calendar based on the Chinese have recorded the eclipses of the Sun and the Moon. The Early astronomers whose names we were the Greek philosophers, like tales, Pythagoras, Eratosthenes heptarchs, Aristech’s and Ptolemy. The astronomers like Nicholas Copernicus. Tyco brave, Johannes keeper and astronomy. Edwin Hubble. Cecelia Payne – Gaposchkin, William hugging. Percival Lowell, Eleanor Helen, William Herschel are some of the modern astronomers.

Newton‘s laws of gravity established the science of celestial mechanics. Astronomy first centered on the solar system, later explored the stars and distant galaxies. By 1900, astronomers began taking photographs of heavenly bodies instead of making visual observations. With the discovery of structure of atom, the astronomers started of atom, the astronomer’s started the study of nature of stars by analyzing starlight. Today’s an astronomer is no longer person working in many fields of science but is a specialist on the specific aspect of science but is a specialist on the specific aspect of astronomers. Research in astronomy is of two types – theoretical and observational. Theoretical studied predict and interpret the behaviors of astronomical bodies while the observational work produces the facts on which theories must be based.

Bode's Galaxy

The Hubble Space Telescope has sent back the best view yet of a picture-perfect galaxy known as M81 or Bode's Galaxy, resolving single points of starlight as well as star clusters and glowing regions of fluorescent gas. The pronounced grand-design spiral galaxy M81 forms a most conspicuous physical pair with its neighbor, M82, and is the brightest and probably dominant galaxy of a nearby group called M81 group. A few tens of millions years ago, which is semi-recently on the cosmic time scale, a close encounter occurred between the galaxies M81 and M82. M81, which lies 11.6 million light-years away in the northern constellation Ursa Major, is a popular target for astronomers and amateur stargazers. It can be seen in clear, dark skies with binoculars or a small telescope. Using the Hubble Space Telescope, a team under Wendy Freedman of the Carnegie Institution of Washington has investigated 32 Cepheid variables in M81 and determined the distance to be 11.0 million light years, in 1993 well before the HST was refurbished. Together with the new distance scale correction implied by the results of ESA's Hipparcos satellite, the true distance of M81 is probably closer to 12.0 million light years

Mountains and Oceans on the Earth

The crust of the earth is its outer most surface layer which is about 6- 35 km thick. It is not an even surface but forms hollows that are full of water. These are called and ridges and wrinkles that are the great mountain chains. This outer surface of the Earth moves constantly producing the oceans and mountains.

Mountains also keep growing or eroding. But these are very slow processes that take several million years to occur. The vast Himalayan mountain range in Asia began to grow 50 million years ago, but it is so young that it is still being formed. The Aravalli range, in the south west of Delhi and in Rajasthan, is believed to be the oldest mountain range in the world. It is eroding and degenerating.