Space Glossary
Quick definitions for the most common space science terms.
Asteroid
A rocky object orbiting the Sun, smaller than a planet.
Comet
An icy body that releases gas and dust when near the Sun.
Exoplanet
A planet that orbits a star outside our solar system.
Light-Year
Distance light travels in one year, about 9.46 trillion km.
Nebula
A vast cloud of gas and dust in space.
Redshift
Light stretched to longer wavelengths as objects move away.
Solar Wind
A stream of charged particles flowing from the Sun.
Spectroscopy
Analyzing light to determine composition and motion.
Transit
When a planet passes in front of its star from our view.
Telescope
An instrument that collects light to view distant objects.
Aurora
Light displays caused by solar particles hitting an atmosphere.
Orbit
The path one object takes around another due to gravity.
Escape Velocity
Speed needed to break free from a body's gravity.
Kuiper Belt
Region beyond Neptune filled with icy objects.
Gravity Assist
Using a planet's gravity to change a spacecraft's path.
Rover
A robotic vehicle that explores planetary surfaces.
How to Use This Glossary
Use these definitions when reading space news, mission updates, and observation guides.