Constellations & Astronavigation

Constellation: a group of stars that forms a particular shape in the sky and has been given a name

Orion This constellation is best seen in the winter sky. It is best seen in the month of January at 9:00pm. Orion, lies on the celestial equator. It is one of the brightest and best known constellations in the sky. It is also one of the few constellations known since ancient times

Perhaps second only to the Big Dipper in Ursa Major, the constellation of Orion is one of the most recognizable patterns of stars in the northern sky. Orion, the hunter, is accompanied by his faithful dogs, Canis Major and Canis Minor. Together they hunt various animals, including Lepus, the rabbit, and Taurus, the bull. According to Greek mythology, Orion was in love with Merope, one of the Seven Sisters who form the Pleiades, but Merope would have nothing to do with him. Orion's tragic life ended when he stepped on Scorpius, the scorpion. The gods felt sorry for him, so they put him and his dogs in the sky as constellations. They also put all of the animals he hunted up there near him. Scorpius, however, was placed on the opposite side of the sky so Orion would never be hurt by it again. Mythology

Picture by National Geographic Society (Copyright)

Ursa Major This constellation can be seen best in the spring sky. It can be seen best in the month of April at 9:00pm. Ursa Major is a prominent constellation in the northern hemisphere. It is the third largest constellation in the sky. Its name is Latin for the Great Bear. Also often referred to as the Big Dipper 

According to some Native American legends, the bowl of the Big Dipper is a giant bear and the stars of the handle are three warriors chasing it. The constellation is low in the sky in autumn evening sky, so it was said that the hunters had injured the bear and its blood caused the trees to change color to red. The Big Dipper is one of the most recognizable patterns in the northern sky. In other cultures it was identified as a wagon or cart, a plow, a bull's thigh, and (to the Chinese) the government. The Big Dipper was also a very important part of the Underground Railroad which helped slaves escape from the South before the Civil War. There were songs spread among the slave population which included references to the "Drinking Gourd." The songs said to follow it to get to a better life. This veiled message for the slaves to flee northward was passed along in the form of songs since a large fraction of the slave population was illiterate. Mythology

Picture by National Geographic Society (Copyright)

Ursa Minor This constellation can be seen best in the summer sky. It can be seen best in the month of June at 9:00pm. Ursa Minor, or the Little Dipper, is a small constellation in the northern hemisphere. In Latin, its name means "little bear." The constellation was originally listed by the Greek astronomer Ptolemy in the 2nd century.  Ursa Minor is usually depicted as a small bear with a long tail. It is said that the tail is so long because the bear is held by its end and spun around the pole. 

The constellation Ursa Minor contains the group of stars commonly called the Little Dipper. The handle of the Dipper is the Little Bear's tail and the Dipper's cup is the Bear's flank. Arcas was the son of Callisto, who was transformed by Juno into a bear. When Arcas was fifteen, he was out hunting in the forest when he came across a bear. The bear behaved quite strangely, looking him in the eyes. He of course could not recognize his mother in her strange shape, and was preparing to shoot her when Jupiter prevented him. Arcas was transformed into a bear like his mother, and the two were taken up into the sky. The mother bear is Ursa Major. Mythology

Picture by National Geographic Society (Copyright)

Early Astronavigational Tools

Compass An instrument used for navigation; it generally has a magnetic needle that points toward the earth's magnetic North Pole. Before the compass, geographical position, destination, and direction at sea were primarily determined by the sighting of landmarks and the observation of the position of celestial bodies (sun/stars). Has been in existence for over 3,000 years. 

Astrolabe Created over 2,000 years ago An ancient astronomical computer for solving problems relating to time and the position of the Sun and stars in the sky.  Typical uses of the astrolabe include: Finding the time during the day or night Finding the time of a celestial event such as sunrise or sunset Find one’s position Astrolabes were also one of the basic astronomy education tools in the late Middle Ages. 

Sextant Used as a navigational tool out at sea Helps determine a ship's longitude and latitude by measuring angles between the horizon and celestial bodies (sun/stars). A more advanced version of the astrolabe. First one was created by Englishman John Bird in 1757.

Telescope Invented in the Netherlands in 1608 (Not by Galileo as most people believe…his came in 1609). Quickly became the astronomer's most essential tool. Now astronomers could see countless stars and other faint objects never before visible…no longer limited to what the naked eye could see.