Astronomy Glossary

Explore 128 astronomical terms with clear definitions and real-world examples

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128

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44

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58

⭐⭐ Intermediate

26

⭐⭐⭐ Advanced

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Nadir

⭐

Astronomy Concepts

The nadir is the point directly below the observer (altitude = -90°), opposite the zenith.

Near-Earth Object (NEO)

⭐⭐

Solar System

Near-Earth Objects are asteroids or comets with orbits bringing them within 1.3 AU of the Sun, potentially crossing Earth's orbit and posing impact ha...

Neutron Star

⭐⭐⭐

Stellar Objects

A neutron star is the ultra-dense remnant of a massive star's supernova explosion, composed almost entirely of neutrons and supported by neutron degen...

Newtonian Telescope

⭐⭐

Telescopes Equipment

The Newtonian design uses a parabolic primary mirror at the tube's base and a flat secondary mirror near the top to reflect light to a side-mounted ey...