Orion Nebula

Orion Nebula

We can ask the computer to run a constellation forward into time. Consider Leo the Lion. The zodiac is a band of twelve constellations seemingly wrapped around the sky in the apparent annual path of the Sun through the heavens.

The root of the word Zodiac is that for zoo, because the zodiacal constellations, like Leo, are mainly fancied to be animals. A million years from now, Leo will look still les like a lion than it does today. Perhaps our remote descendants will call it the constellation of the radio telescope – although I suspect a million years from now the radio telescope will have become more obsolete than the stone spear is now.

The stars flash on and wink off like fireflies in the night (quotations from Megan Jorgensen). Image © Meg Jorgensen (Elena)

The nonzodiacal constellation of Orion, the hunter, is outlined by four bright stars and bisected by a diagonal line of three stars, which represent the belt of the hunter. Three dimmer stars hanging from the belt are, according to the conventional astronomical projective test, Orion’s sword. The middle star in the sword is not actually a star but a great cloud of gas called the Orion Nebula, in which stars are being born.

Many of the stars in Orion are hot and young, evolving rapidly and ending their lives in colossal cosmic explosions called supernovae. They are born and die in periods of tens of millions of years. If, on our computer, we were to run Orion rapidly into the far future, we would see a startling effect, the births and spectacular deaths of many of its stars, flashing on and winking off like fireflies in the night.