Orion, the mighty hunter

Looking at the stars has been a favorite pastime for many generations. Ancient civilizations had a much better view at the stars than we do; people tended to live outdoors much more often and there was no light pollution. The manner in which we identify stars is still influenced by the way people perceived the stars in ancient times: hence the constellations. Orion, the hunter, is one of the most recognizable constellations in the sky.

Constellations are configurations of stars in which they are perceived from Earth. Because space is three dimensional, the constellations have nothing to do with the actual locations of the stars. The stars in one constellation can be many light-years apart and appear close together only from an Earth point of view. The most modern constellations come from the ancient Greeks, like the constellation of Orion, the hunter.

Greek mythology

In Greek mythology Orion was a giant and a powerful hunter. According to one story he became very arrogant and bragged that he would kill all animals on earth. The gods were angered and sent a scorpion to kill Orion. The two fought all day but neither was able to best his opponent and the fight was suspended. Orion, terribly tired, fell asleep and the scorpion saw his opportunity to sting him. Orion woke up and killed the scorpion but the poison had already done its damage and Orion died. The gods placed Orion and the Scorpion in the sky but far apart so that they would never fight again. When Orion sets in the West, Scorpio rises in the East. A different story tells of Artemis, the goddess of the moon and hunting, falling in love with Orion. Her twin brother Apollo was jealous and challenged her to hit a figure swimming far out at sea with an arrow. Artemis was not aware that the figure was Orion and killed him with her arrow. When she realized what she had done she placed him, together with his hunting dogs, in the night sky. Her sorrow explains the paleness of the moonlight.

Other Cultures

Different cultures also noticed a pattern in this particular group of stars. The Chaldeans knew this group of stars as Tammuz, after the month in which the belt rose just before sunrise. The Syrians called it Al Jabar, a giant and for the ancient Egyptians it was Sahoe, the soul of Osiris. The Khoisan (or Bushmen) tell of Aob the hunter, depicted by Alderbaran in the constellation Taurus, who was sent by his women (the Pleiades) to hunt. He shot an arrow at the three zebras depicted represented by the three stars in Orion's belt, but missed. He could not retrieve his arrow because a lion (Betelgeuse) was lurking nearby and the three zebras fled to Earth. Many other African cultures saw three animals in the stars that make up Orions belt.

Science

Orion is one of the most recognizable constellations in the night sky with its three bright stars in a row that form the belt. From left to right these are: Alnitak, Alnilam and Mintaka. These stars are some of the furthest that one can still see with the naked eye, Alnilam is no less than 1340 light-years away. This means that the light of this star takes 1340 years to reach us! Light travels at a speed just under 300,000 kilometers per second. Alnitak and Minataka are located respectively 820 and 915 light-years away. The two bright stars above the belt are Betelgeuse (left) and Bellatrix (right), these form the shoulders of the hunter. Below the belt two other bright stars are his feet. The star on the right is called Rigel and is 40,000 times brighter than our sun at a distance of 773 light-years. Betelgeuse is a red giant nearing the end of its life. If you look closely you can see a red glow coming from this star, this is because the star has nearly exhausted its supply of Hydrogen and the surface temperature is decreasing. Soon (by astronomical measures, which means within several thousand years) this star will form a supernova. This means that the star will explode and the outer layers are expelled causing it to briefly flare up for a few more months. What remains is a nebula, while the core of the exploded star forms a compact neutron star. Just below the belt you can see three stars that together make up Orions knife. The one in the middle is not a real star but a nebula called the Great Orion Nebula. Even with an ordinary binocular you can see that its not a star but a blurry sphere of light. A nebula is a cloud of interstellar gas which forms a nursery for new stars.

Sources: www.todio.nl