An Introduction to Astronomy

We ae all novices when it comes to the vast wonders of the universe. Get started with key definitions and answers to frequently asked questions about astronomy and space exploration.

  • What are Rotation and Revolution?
  • Seine et Marne. Focus on one of the most beautiful stars of heaven: Vega in the constellation Lyra. The blue star is located 25 light years from Earth and is clearly visible, especially in summer.
    Vega Star Facts on Our Future North Star
  • Hawaii, Mauna Kea Observatory
    Astronomy: The Science of the Cosmos
  • Artwork of a Galaxy as Whirlpool in Space
    Can We Travel Through Time to the Past?
  • Image of the moon's far side
    What's Really on the Far Side of the Moon
  • The timeline of the universe
    How Did the Universe Get Started?
  • massive stars in the peony nebula
    All About Nebulas
  • Star chart of constellations and asterisms
    Understanding Star Patterns and Constellations
  • Nasa artwork of a crew of astronauts on the moon with a rover
    What Happens to the Human Body in a Vacuum?
  • hs-2009-14-a-large_web_galaxy_triplet.jpg
    The Top Space Questions
  • View from a water world
    How Many Habitable Planets are Out There?
  • sound in space
    Can Humans Hear Sound in Space?
  • earth and its seasons
    The Reasons for the Seasons
  • smallerAndromeda.jpg
    What is Blueshift?
  • trumpler 14 and massive stars
    Astronomy 101 - Learning About Stars
  • people gazing up at Milky Way in the night sky
    5 Magazines for Astronomy and Space Information
  • Artist's Concept of Nearest Exoplanet to Our Solar System Around Epsilon Eridani
    Does Life Exist Elsewhere in the Cosmos?
  • Claudius Ptolemy
    Trace the Earliest History of Astronomy
  • Redshift
    How Redshift Shows the Universe is Expanding
  • doppler shift
    Learn about the Doppler Effect
  • observatories_across_spectrum_labeled_full-1-.jpg
    Radiation in Space Gives Clues about the Universe
  • orbits
    Explore Johannes Kepler's Laws of Motion
  • galileo and telescope
    Who Invented the Telescope?
  • Trumpler 14 star cluster star luminosities
    What Is Luminosity?
  • smallerAndromeda.jpg
    The Composition of the Universe
  • Detailed full-sky map of the oldest light in the universe captured by the Wilkinson Microwave Anisotropy Probe
    Microwave Astronomy Helps Astronomers Explore the Cosmos
  • dark matter blobs
    Cold Dark Matter
  • dark matter blobs
    What is Matter?
  • Car lights, Bernina Pass, Switzerland
    Learn About the True Speed of Light and How It's Used
  • space_+station_nasa.jpg
    Where Does Space Begin?
  • telescope over a landscape and cloudy sky
    The Basics of Telescopes
  • radio telescopes
    How Radio Waves Help Us Understand the Universe
  • wormhole travel
    Time Travel: Dream or Possible Reality?
  • Stonehenge, near Salisbury, Great Britain
    A Guide to Solstices and Equinoxes
  • full moon as seen from outer space
    Reasons for Humanity to Go Back to the Moon
  • antares_m4.jpg
    What Is Astronomy and Who Does It?
  • stargazingpeopleC2014CCPetersen.jpg
    How Many Stars Can We See At Night?
  • 800px-Astronomy_Amateur_3_V2.jpg
    Deciphering Star Charts for Skygazing
  • Full Super Moon
    Full Moon Names and their Meanings
  • Stargazing group
    Stargazing Through the Year
  • The sidereal month and synodic month are both based on the lunar cycle.
    Sidereal Month Versus Lunar Month (Synodic)
  • The_bright_star_Alpha_Centauri_and_its_surroundings-1-.jpg
    Alpha Centauri: Gateway to the Stars
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