In 72 Beautiful Galaxies we take you on a trip from relatively near to very far away in the universe, with images of 72 galaxies - and beyond that you will also see hundreds of galaxies as they are found in clusters. You will see that galaxies come in many shapes and sizes, with major categories being spirals and ellipticals. There are also many irregular galaxies and galaxies undergoing mergers or being cannibalized by other galaxies. Galaxies vary tremendously in their masses, in their luminosities, in their shapes, in their star formation rates, and in the amount of gas and dust they contain. And some are near, in cosmic terms, and some are billions of light-years away, at the edge of the universe. Many are found in groups, including our own Milky Way. Others are found within very large clusters. This book has been designed to provide you with some appreciation of the variety of galaxy types, as well as their beauty, and some feeling for what astronomers are seeking to understand as we explore and discover more and more galaxies with the Great Telescopes of our day.

Dark Matter, Dark Energy and Dark Gravity make life possible!This book for the lay reader provides a summary of the latest astrophysical observational results and theoretical insights into what we know and what we hope to learn about dark matter, dark energy, and dark gravity.How did the profound beauty of our Earth, our Solar System, our Milky Way galaxy and indeed our universe unfold? Dark matter, dark energy, and dark gravity have made all the difference in how the universe has developed, and have been key to creating the overall environment that makes life possible. We have only recently developed the ability to begin unlocking their secrets, thus providing a deeper insight into how a universe of our type is possible. It seems that because of dark matter, dark energy and dark (weak) gravity, our universe has the right attributes for the development of complex structure and the evolution of intelligent life that can engage in the quest to understand our world. These "dark" or more hidden attributes of the cosmos have very good outcomes.In particular, the existence of dark matter makes it easier to form complex structures, including galaxies, stars and planets through gravitational collapse of denser regions of the universe. Planets are the most suitable abodes for the development of life. Dark energy acts to extend the lifetime of the universe by counteracting gravity and driving continued expansion of the universe.Even as far back as the 1930s there has been evidence that most of the matter in the universe was not visible via electromagnetic radiation (optical light, radio waves, etc.). By the last few decades of the 20th century, the case for a considerable amount of this dark matter was very strong. It is the second largest contributor to the total mass-energy of the universe. We don't know what it is and there are various candidates to explain it; nevertheless we see the gravitational effects of dark matter everywhere on the largest scales. Recent observational results indicate that dark matter dominates by a factor of 6 relative to the ordinary matter that makes up stars, planets, and living things.We now know that the major contributor to the mass-energy of the universe is not the substantial dark matter, but the 'newer' so-called dark energy. Dark energy acts to some extent as a negative gravity, and for the last several billion years has driven the expansion of the universe to a faster and faster pace, overcoming even the gravitational effect of dark matter. We have a general idea that it is the irreducible energy found in every volume of space, even in the absence of matter - in the vacuum. We don't understand why it takes the value that it does, one that is small in quantum particle physics terms, but nevertheless is of great significance on the large cosmological scale of the universe. The third important aspect to consider is not a mass-energy component, but the nature of gravity and space-time. The big question here is - why is gravity so relatively weak, as compared to the other 3 forces of nature? These 3 forces are the electromagnetic force, the strong nuclear force, and the weak nuclear force. Gravity is different - it has a dark or hidden side. It may very well operate in extra dimensions beyond the normal 4 dimensions of space-time that we can observe. This is what we mean in this book by "dark gravity".

A thought provoking study of the powerful impact of images in guiding astronomers' understanding of galaxies through time.

Some time ago, the renowned astronomer Patrick Moore - best known for his BBC TV programme The Sky at Night which has screened continuously for 42 years - devised a catalogue of 109 deep space (galaxies, nebulae, clusters) objects to which he has lent his middle name Caldwell. Thus Caldwell objects, numbered C1 to C109.Why Caldwell and not Moore? The most famous of all catalogues of astronomical objects was created by Charles Messier in 1774, and these are designated by M1 to M109, so Patrick Moore could not use his own surname, but instead elected to use his middle name Caldwell. And Patrick Moore chose 109 object to match Messier, though it is important to understand that not one of Patrick Moore's objects overlaps with Charles Messier's.Messier was in fact a comet hunter - in the eighteenth century comets were not understood at all and had huge significance when they appeared blazing across the clear skies, as yet free from the light pollution we experience. He catalogued galaxies, nebulae and clusters not because he was particularly interested in those objects, but because he did not want these objects to be confused with ne

Appendix C William Herschel: the greatest visual observer of all time - by Larry Mitchell -- Appendix D Image credits -- Index

1,001 Celestial Wonders is a guide to the night sky's brightest and most fascinating objects. Each target is accessible to amateur astronomers using medium-sized telescopes from a dark site. In fact, many are so bright they remain visible under moderate light pollution, as from the outskirts of a city or the suburbs of a town. The book provides a chronological target list, making it easy to use. No matter what night you choose, this book will show you many of the most memorable objects to observe, whether you are using a small telescope or even binoculars, or an instrument of larger aperture. This is far more than just a list of interesting objects. It is structured so that objects of various observing difficulty are included, which will help readers become better observers, both encouraging beginners and challenging long-time amateur astronomers. This book is designed to be easy-to-use at the telescope, and observers will appreciate each object's standardized layout and the book's chronological organization. Finally, many amateur astronomers function best when presented with a list! Even the Meade Autostar® controller features a 'best tonight' list (although the list is far less comprehensive and detailed than the catalog provided in this book), a feature that has proved extremely popular. 1,001 Celestial Wonders offers a life-list of objects any observer would be proud to complete.

A lucid, wide-ranging graduate textbook on the topical subject of galactic chemical evolution - by a pioneer of the field.