Britannica Educational Publishing 
Astronomical Observations [PDF ebook] 
Astronomy and the Study of Deep Space

The night sky is positively teeming with wonders, from star clusters and nebulae to quasars. Astronomy is the means by which these and other similar phenomena are discovered and observed. This stellar resource traces the path of modern astronomy, from initial efforts to map the heavens to today’s use of high-tech telescopic devices that help people delve deeper into celestial discovery.