#space science

• Andromache — An international graphic variant of Hellenic or Anglo-Saxon origin for the name Andromaca, widely used in global academia. In a scientific and structural astronomical context, the name designates the main-belt asteroid '175 Andromache', discovered in the 19th century by astronomer James Craig Watson.
• Andromeda — A heroine in Greek mythology, daughter of King Cepheus and Cassiopeia, rescued from a sea monster by Perseus. In modern astronomy, the term designates a northern constellation and, notably, the Andromeda Galaxy (M31), a massive spiral galaxy located structurally as the Milky Way's closest major galactic neighbor.
• Andromedid — A meteor belonging to the Andromedids, a meteor shower historically associated with the disintegration of Biela's Comet. This structural astronomical phenomenon has its radiant in the Andromeda constellation and is recognized for spectacular meteor storms recorded in the 19th century, currently remaining a faint shower tracked for comet debris analysis.
• Antapex — An imaginary point on the celestial sphere, located in the constellation Columba, away from which the solar system moves in its global galactic motion relative to nearby stars. This astronomical structural element is located exactly one hundred and eighty degrees away, being diametrically opposed to the solar apex.
• Astrobiologist — A scientist or specialist who works in the field of astrobiology; a researcher focused on the interdisciplinary study of the origin, evolution, distribution, and future of life in the universe. They combine knowledge of biology, chemistry, geology, and astronomy to investigate potential biospheres on other celestial bodies, the survival limits of organisms in extreme environments, and cosmic biosignatures.
• Astrobiologist — A woman who works as an astrobiologist; a female specialist in the scientific investigation of the chemical and biological premises of life outside Earth. Her activity includes laboratory simulations of exoplanetary atmospheres, the study of extremophile organisms, and the interpretation of spectrographic data obtained from space telescopes to identify potential extraterrestrial habitats.
• Astrobiology — An interdisciplinary branch of science that studies the origin, evolution, distribution, and future of life in the universe, both on Earth and in outer space. It combines principles from astronomy, biology, chemistry, geology, and planetary physics to understand how habitable environments emerge, how life develops in extreme conditions, and how biosignatures can be detected on other planets or natural satellites.
• Astronomy club — An association, organization, or cultural-scientific club formed by amateur astronomers, professionals, and cosmology enthusiasts, aiming to promote astronomy, organize public celestial observations, technical workshops, and expeditions for viewing eclipses or meteor showers. This community structure provides members with access to shared optical instruments, databases, and mentoring platforms for astrophotography or observational research.
• Astrophysical — Belonging to astrophysics, relating to astrophysics; referring to the application of the laws, methods, and principles of physics to the study of the structure, chemical composition, evolution, and dynamic phenomena of celestial bodies (stars, planets, galaxies, black holes) and interstellar space. It also defines the instruments, research, or mathematical models used to explain the behavior of matter and energy on a cosmic scale.
• Astrophysics — A branch of astronomy and modern physics that studies the physical properties, chemical composition, structure, dynamics, and evolution of celestial bodies (stars, planets, galaxies, nebulae) as well as the interstellar or intergalactic medium. This discipline applies the laws of thermodynamics, quantum mechanics, relativity, and electromagnetism to explain complex cosmic phenomena, from stellar nuclear fusion processes to cosmic microwave background radiation.
• Astrophotometer — A high-precision astronomical instrument (equipped with photoelectric sensors or calibrated CCD/CMOS cells) used in astrophotometry to quantitatively measure the luminous flux, intensity, and brightness of radiation emitted by celestial bodies. This device allows comparing the magnitude of a target star with a standard artificial light source or reference stars, forming the basis for calculating light curves of variable stars and detecting extrasolar planets.
• Astrognosy — An old descriptive branch of practical astronomy that deals with identifying, naming, and mapping constellations, as well as recognizing the position of the main stars and celestial bodies visible to the naked eye or rudimentary instruments. Unlike modern astrophysics, this classic field focuses strictly on sky orientation, traditional star charts, and celestial nomenclature.
• Astrometric — Belonging to astrometry, relating to astrometry; referring to the precise geometric measurement of positions, angular distances, and proper motions of celestial bodies on the celestial sphere. This term defines the methods, coordinate catalogs, instruments (such as scanning telescopes), or satellite data (such as those provided by the Gaia mission) used to establish fundamental star charts.
• Astrometry — A fundamental branch of positional astronomy that deals with the precise geometric measurement of positions, proper motions, angular distances, and parallaxes of celestial bodies on the celestial sphere. This field establishes space reference systems and fundamental coordinates indispensable for galactic mapping, calculating planetary orbits, or detecting subtle gravitational perturbations generated by exoplanets.
• Astronomical — Belonging to astronomy, relating to astronomy; based on the laws, methods, and principles of studying celestial bodies. In colloquial, journalistic, or economic language, the term is used hyperbolically to describe a huge, exaggerated, substantial figure, sum of money, distance, or proportion that exceeds ordinary limits and recalls the vastness of cosmic dimensions.
• Astronomy — A fundamental and natural science that deals with the study, observation, measurement, and physico-mathematical interpretation of celestial bodies (stars, planets, satellites, comets, asteroids, galaxies), cosmic structures, and the universe as a whole. This discipline investigates the origin, evolution, chemical composition, and motion dynamics of matter and energy in extra-atmospheric space, being one of the oldest branches of human knowledge.
• Astrospectroscopy — A fundamental field of astrophysics dealing with the qualitative and quantitative study of the electromagnetic radiation spectra emitted or absorbed by celestial bodies. This discipline analyzes spectral lines decomposed via diffraction gratings or prisms to deduce the chemical composition, effective temperature, surface gravity, radial velocity, and rotational motions of cosmic objects in the universe.