Astronomy is the science of motion, structure and evolution of celestial bodies and their systems up to the universe as a whole. In particular, astronomers study the sun, planets in our solar system and their moons, asteroids, comets, meteors, interplanetary matter, stars and extrasolar planets (exoplanets), nebulae, interstellar matter, galaxies and their clusters, pulsars, quasars, black holes and much more. Space stations are designed to help in the investigations of the planets and the sun. Astronomy studies influence of space on Earth life. Astronomy is one of the oldest sciences. Prehistoric cultures have left behind such astronomical artifacts as ancient Egyptian monuments and Stonehenge. And the first Earth civilization of the Babylonians, Greeks, Chinese, Indians and the Mayans already in time spent methodical observation of night sky. After the invention of the telescope and such space-based technologies like oso (orbiting solar observatories) the development of astronomy, as modern science has been greatly accelerated. Historically, astronomy included astrometry, navigating by the stars, observational astronomy, the creation of calendars, and even astrology. Professional astronomy is nowadays often regarded as synonymous with astrophysics. In XX century, astronomy was divided into two main branches: the observation and theoretical. Observational astronomy is focused on getting data from observations of celestial bodies, which are then analyzed using the basic laws of physics. Theoretical astronomy is oriented towards the development of computer, mathematical or analytical models to describe astronomical objects and phenomena. These two branches complement each other: theoretical astronomy seeking to explain the observation results, and observational astronomy used to confirm the theoretical findings and hypotheses.