science

• In 1929, the International Astronomical Union (IAU) officially defined 88 constellations across the span of the sky
• The constellations were originally defined by their shapes and patterns
• Early in the 20th century, astronomers decided to have an official set of constellation boundaries
• Reason for official constellation boundaries

  To aid in the naming of new variable stars, which brighten and fade rather than shine steadily
• Formally cementing these boundaries allows astronomers to communicate about the regions of the sky they study
• The official constellations are in fact rectangular slices of the heavens holding the stars within it
• Included are the individual groupings, for instance the constellation of Ursa Major contains all of the stars around the shape known by the same name
• Many of the constellations have names that can be traced back to early Babylonians and Greek civilizations, but nearly all cultures have different names for them
• Christian Filipinos named the three stars at Orion's belt as Tatlong Maria or Tres Marias
• Today, different cultures still see different shapes in the stars in the sky
• Astronomers have agreed on the names and locations of the constellations
• Circumpolar constellations


  Constellations that can be seen all-year round as they never set below the horizon of a viewer's perspective
• Examples of circumpolar constellations


  • Ursa Major
  • Ursa Minor
  • Cassiopeia
  • Draco
• The brightest constellation is Crux (The Southern Cross)
• The constellation with the greatest number of visible stars in it is Centaurus (The Centaur) with 101 stars
• The largest constellation is Hydra (The Water Snake) which extends over 3.158% of the sky
• Asterisms


  Smaller apparent star patterns within a constellation
• The Zodiac Constellations contain some of the brightest stars in the sky
• The Zodiac Constellations lie along the path of the Sun across the sky as seen from Earth, known as the ecliptic path
• The Sun appears to pass through these constellations over the course of a year
• The passage of the Sun through the constellations of Aries, Cancer, Libra, and Capricorn also mark the beginning of the four seasons
• Two more constellations, Ophiuchus and Cetus the Whale, also cross the ecliptic path
• Ophiuchus is located between Scorpio and Sagittarius
• Today, the Zodiac Constellations are associated with astrology
• Astrologers use 12 of these constellations as signs of the Zodiac, omitting Ophiuchus, to make predictions
• Unlike astronomy, astrology is not a science
• Signs differ from constellations, bearing only a loose reference to one another
• The sign of Pisces corresponds to the rise of the constellation of Aquarius
• If you are born under a particular sign, that constellation it is named for is not visible at night, as the Sun is passing through it around that time of year, making it a daytime constellation that can't be seen
• Constellation families


  • Ursa Major Family
  • Perseus Family
  • Hercules Family
  • Orion Family
• The constellations appear to form shapes across the sky, but the stars themselves don't make up patterns in space
• The distance from our world to the individual stars in a constellation varies, often by tens of light-years scattering the stars randomly across the galaxy
• Constellations can provide entertainment and a source of imagination, help the lost to find their way, and aid sky watchers in the search for planets, comets, or other events, by a process called star hopping
• To an astronomer, a constellation is an entire section of the sky, and each constellation shares a border with a neighboring constellation
• Every star or galaxy in the sky is located within one of 88 constellations
• As the Earth travels around the sun, different areas of the universe are visible, and different constellations are visible from different points on the Earth
• The apparent motion of the stars and planets is caused by Earth's rotation, as different parts of the universe become visible to people on the Earth
• Weather is the condition of the atmosphere over a short period of time, and climate is how the atmosphere behaves over relatively longer periods
• Climate is mainly determined by temperature and precipitation
• Other factors that affect climate include latitude, prevailing wind patterns, landforms, and ocean currents