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Astronomy

The scientific study of celestial bodies, space, and the universe as a whole.

Observational Astronomy

The branch of astronomy that focuses on collecting data from celestial observations.

Theoretical Astronomy

The branch of astronomy that develops analytical or computational models to describe astronomical phenomena.

Amateur Astronomy

The practice of astronomy by non-professionals, often contributing meaningfully to discoveries.

Constellations

Groups of stars forming recognizable patterns, often named after mythological figures.

Magnitude Scale

A system introduced by Hipparchus that ranks stars based on brightness.

Celestial Sphere

An imaginary sphere surrounding Earth where all celestial bodies appear to be projected.

Ecliptic

The Sun’s apparent annual path through the celestial sphere.

Zenith

The point directly overhead from an observer's position.

Precession

The gradual change in the orientation of Earth's rotational axis caused by gravitational forces.

Saros Cycle

An 18-year, 11 1/3-day cycle used to predict eclipses.

Phases of the Moon

The appearance of the Moon as it orbits Earth, influenced by its position relative to the Sun and Earth.

Spring Tides

Tides that occur when the gravitational forces of the Moon and Sun align, resulting in higher high tides.

Neap Tides

Tides that occur when the gravitational forces of the Moon and Sun are at right angles, resulting in lower high tides.

Eclipse

An astronomical event where one celestial body passes through the shadow of another.

Heliacal Rising

The first visibility of a star or planet just before sunrise.

Optical Illusions in Astronomy

Phenomena that can cause celestial bodies to appear differently than they truly are due to atmospheric effects.

Big Bang

The initial singularity event that marked the beginning of the universe approximately 14 billion years ago.

Solar System Formation

The process by which the solar system was developed from a massive molecular gas cloud around 4.5 billion years ago.

Cosmic Evolution

The gradual development of the universe's structure from the Big Bang to present-day galaxies and cosmic phenomena.

Astrolabe

An ancient astronomical instrument used for solving problems related to time and the position of the stars.

Lunar Month

The period it takes for the Moon to complete one full cycle of its phases, typically about 29.5 days.

Zodiac Signs

The twelve constellations along the ecliptic, historically used in astrology.

Stonehenge

A prehistoric monument in England believed to have been used for astronomical observations.