To the ancient Maya, the Orion Nebula was the fire of creation. The bright stars around it were the hearthstones that held the fire.

And they were on the right track. The nebula is a giant stellar nursery. It’s given birth to thousands of stars, with more still taking shape. And the “hearthstone” stars are related to the fire. The whole group is part of a massive complex of young stars, plus lingering clouds of gas and dust.

It’s known as the Orion O-B-1 association. The letters refer to the group’s many class O and B stars, which are much bigger and brighter than the Sun. Such stars live for millions of years, versus billions of years for the Sun.

The association consists of four big clumps. One of them is north of Orion’s Belt. Another includes the belt. The others are south of the belt, with the Orion Nebula at the end of the chain.

The stars in the northern group are the oldest. They’ve blown away the remaining gas, so no new stars are being born there. The Orion Nebula is in the youngest group. Some of its stars are less than a million years old. The stars of the belt are between those ages; more about the belt tomorrow.

The association also includes thousands of smaller, fainter stars. But the O and B stars are the real standouts.

Orion is in the east and southeast at nightfall. Its belt extends upward from the horizon. The Orion Nebula looks like a fuzzy star to the right of the belt – a fiery hearth of creation.

Script by Damond Benningfield