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Astronomical
Stars, planets, constellations, and what's overhead when the sun goes down.
140
entries
9
types
Did you know
Light from Andromeda — the nearest large galaxy — takes 2.5 million years to reach your eyes.
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Constellations
A recognized grouping or pattern of stars in the night sky.
88
Stars
A luminous celestial body composed primarily of hydrogen and helium.
28
Planets
A large celestial body orbiting a star.
9
Nebulae
A large cloud of gas and dust in space.
8
Galaxies
A massive system of stars, gas, dust, and dark matter bound together by gravity.
5
Moons
A natural satellite orbiting a planet.
1
Solar Systems
A star and all celestial bodies gravitationally bound to it.
1
Asteroids
A small rocky body orbiting the sun, mainly found in the asteroid belt.
0
Comets
An icy celestial object that develops a tail when near a star.
0
Featured entries
Hand-picked highlights from the Astronomical library.
Planet
Mars
Mars is the fourth planet from the Sun — the Red Planet, named for the rusty surface color caused by iron oxid…
Planet
Jupiter
Jupiter is the largest planet in our Solar System — more than twice as massive as all the other planets combin…
Moon
Moon
The Moon is Earth's only natural satellite — about a quarter Earth's diameter, with surface gravity about one-…
Planet
Venus
Venus is the second planet from the Sun and Earth's near-twin in size and mass — sometimes called our sister p…
Constellation
Andromeda
The Chained Maiden. Home to the Andromeda Galaxy.
Nebula
Crab Nebula
The Crab Nebula is the expanding wreckage of a supernova explosion observed and recorded by Chinese, Japanese,…
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