Discovery and exploration of the Solar System

Discovery and exploration of the Solar System is observation, visitation, and increase in knowledge and understanding of Earth's "cosmic neighborhood".^[1] This includes the Sun, Earth and the Moon, the major planets Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, their satellites, as well as smaller bodies including comets, asteroids, and dust.^[1]

In ancient and medieval times, only objects visible to the naked eye—the Sun, the Moon, the five classical planets, and comets, along with phenomena now known to take place in Earth's atmosphere, like meteors and aurora—were known.^{[dubious – discuss]} Ancient astronomers were able to make geometric observations with various instruments. The collection of precise observations in the early modern period and the invention of the telescope helped determine the overall structure of the Solar System. Telescopic observations resulted in the discovery of moons and rings around planets, and new planets, comets and the asteroids; the recognition of planets as other worlds, of Earth as another planet, and stars as other suns; the identification of the Solar System as an entity in itself, and the determination of the distances to some nearby stars.

For millennia, what today is known to be the Solar System was regarded as the "whole universe", so the knowledge of both mostly advanced in parallel. A clear distinction was not made until around the mid-17th century. Since then, incremental knowledge has been gained not only about the Solar System, but also about outer space and its deep-sky objects.

The composition of stars and planets was investigated with spectroscopy. Observations of Solar System bodies with other types of electromagnetic radiation became possible with radio astronomy, infrared astronomy, ultraviolet astronomy, X-ray astronomy, and gamma-ray astronomy.

Robotic space probes, the Apollo program landings of humans on the Moon, and space telescopes have vastly increased human knowledge about the atmosphere, geology, and electromagnetic properties of other planets, giving rise to the new field of planetary science.

The Solar System is one of many planetary systems in the galaxy.^[1][2] The planetary system that contains Earth is named the "Solar" System. The word "solar" is derived from the Latin word for Sun, Sol (genitive Solis). Anything related to the Sun is called "solar": for example, stellar wind from the Sun is called solar wind.