Since its origins, the human species has observed the sky . First, directly, then with increasingly powerful telescopes. Now with many electronic media.
The ancient civilizations grouped the stars into figures. Our constellations were invented in the eastern Mediterranean about 2,500 years ago. They represent animals and myths of the place and time. People believed that the bodies of heaven influenced the lives of kings and subjects. The study of the stars was mixed with superstitions and rituals.
The constellations that accompany the trajectory of the Sun, the Moon and the planets, in the strip called the zodiac , are familiar to us because they appear in the horoscope: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.
At the beginning of the 17th century the telescope was invented. Lenses were used first, then mirrors and also combinations of both. Today there are very high resolution telescopes, even groups of several telescopes working together, synchronized.
Radio telescopes detect radiation of very different wavelengths. They work in groups using a technique called interferometry.
Photography, computers, communications and, in general, technical advances in recent years have helped astronomy a lot.
The Hubble Space Telescope (HST), located in orbit, captures and sends images and data without the distortion caused by the atmosphere.
Thanks to the spectra, produced by the decomposition of light, we can know detailed information about the chemical composition of an object. It also applies to knowledge of the Universe.
A recent finding, gravitational lensing, takes advantage of the fact that objects with mass can deflect light rays. If a group of bodies is located with the appropriate configuration, it acts as a very powerful lens and shows, in the center, distant objects that we could not see.
