Dec 19, 2025 · Astronomy is the study of objects and phenomena beyond Earth, whereas cosmology is a branch of astronomy that studies the origin of the universe and how it has evolved.

ASTRONOMY meaning: the scientific study of stars, planets, and other objects in outer space

Astronomy, science that encompasses the study of all extraterrestrial objects and phenomena. Until the invention of the telescope and the discovery of the laws of motion and gravity in the 17th century,...

The study of astronomy involves all of the objects outside Earth’s atmosphere. These include the Sun, Moon, planets, stars, galaxies, and all other matter in the universe.

Before the dawn of history someone noticed that certain celestial bodies moved in orderly and predictable paths, and astronomy—an ancient science—was born. Yet some of science’s newest …

Jan 3, 2026 · The Sun, Moon, and brightest planets were visible to the naked eyes of ancient astronomers, and their observations and calculations of the movements of these bodies gave rise to …

5 days ago · The rate at which galaxies and large structures composed of galaxies coalesced from density fluctuations in the early universe indicates that the nonbaryonic dark matter is relatively “ …

Dec 20, 2025 · Astronomers define stellar brightness in terms of magnitudes: the apparent magnitude (the perceived and measured brightness of a star) and the absolute magnitude of the brightness of …

Dec 24, 2025 · A parabolic orbit is open, with an eccentricity of exactly 1, meaning the comet would never return. (A circular orbit has an eccentricity of 0.) Any less-eccentric orbits are closed ellipses, …

Dec 19, 2025 · Cosmos, in astronomy, the entire physical universe considered as a unified whole (from the Greek kosmos, meaning “order,” “harmony,” and “the world”). Humanity’s growing understanding …