2009Europa - Astronomy - Sheetlets

International Astronomical Union and UNESCO declared the year 2009 the International Year of Astronomy with the aim of approaching the universe to the people and popularization of astronomy as well as a warning of disappearance of the black sky. World Year of Astronomy was selected because the men relationship toward universe has disappeared, and it is call for people to discover observatories and telescopes and to educate themselves about hurtfulness of excessive artificial lightning, known under the term of light pollution. For the first time, 400 years ago Galileo Galilei used telescope in astronomical purpose, looked the craters on the Moon, rings of Saturn and spots on the Sun. By his telescope he discovered the four largest natural satellite of Jupiter which was the first scientific evidence against geocentric system.