Space

It must be accidental. Consider that Venus, the planet closest to Earth and almost identical in size, has no satellite at all.
http://www.explore-the-moon.com

Learn about planets. Includes info on facts about Mars, Moon facts, planet facts, facts about Earth, facts about Saturn, Sun facts, Jupiter facts, facts about Mercury, Venus facts, Uranus facts, and more.
http://www.planet-facts.net

С развитием науки и техники телескопы стали доступны широкой массе людей, причем достаточно серьёзные телескопы, в которые разглядеть что-
http://astronomija.blackcatpix.com/