Astronomy

Astronomy is the scientific study of celestial objects such as stars, planets, comets, and galaxies, and of phenomena that originate outside Earth's atmosphere, as well as the structure and evolution of the universe as a whole. It encompasses observational data and theoretical models across multiple wavelengths and is distinct from astrology, which interprets celestial positions for human affairs.

The practice traces to ancient civilizations that recorded celestial events and cycles. The development of the telescope in the 17th century revolutionized astronomy, enabling detailed observations of the Moon, planets, and stars. In the 20th century, advances in spectroscopy, theoretical physics, and space-based observatories expanded reach to a broader range of wavelengths and cosmic phenomena, from distant galaxies to the cosmic microwave background.

Subfields include observational astronomy (collecting data across visible, radio, infrared, ultraviolet, X-ray, and gamma-ray bands), theoretical astronomy (developing models of celestial systems), and specialized domains such as cosmology, planetary science, stellar astronomy, galactic astronomy, astrochemistry, and astrobiology.

Methods and tools rely on telescopes and detectors, both ground-based and spaceborne, covering multiple wavelengths. Data analysis, modeling, and simulations are core. Catalogs, surveys, and databases enable large-scale studies of objects and their properties, with international collaborations and peer-reviewed results.

Astronomy informs understanding of physics under extreme conditions, the origins and evolution of the universe, and the potential for life beyond Earth. It contributes technologies such as imaging sensors and data processing and remains a dynamic field with ongoing missions and discoveries.