NASA Podcasts

What’s Up for December?
› View Vodcast
What’s Up for December: the Orion Nebula.

Hello and welcome. I’m Jane Houston-Jones at NASA’s Jet Propulsion Laboratory in Pasadena, California.

This is the final month of International Year of Astronomy. But that shouldn’t stop you from looking up next year.

This month’s target is in one of the most-recognizable constellations: Orion.

The Orion Nebula is easy to find, and it’s one of the most beautiful objects to observe through a telescope. You can see it with your unaided eye, too, even from the city.

Galileo observed and sketched the Orion constellation and even the small grouping of stars in The Trapezium region of the Orion Nebula. But he never wrote about or sketched the nebula itself. No other early astronomers did either.

An observation from 1654 shows not only the three stars Galileo saw, but also the fuzzy patch which we know as the Orion Nebula. In 1656 Christian Huygens made one of the earliest sketches showing more of the nebula.

The Orion Nebula’s glowing gas surrounds hot young stars at the edge of a huge interstellar molecular cloud only 1500 light years away. This is the nearest large star-forming region, and it’s our best window into how stars are born.

In the center of the nebula lie four massive young stars whose stellar winds have carved out a cavity know as The Trapezium. In the same region protoplanetary disks are forming from gas and dust. Solar systems like our own are formed from disks like these.

The stellar winds from stars create bubbles and arcs, bow shocks, and a huge deep bowl.

Dark pillars of gas are found in the outer layers. And cool brown dwarfs lie within the nebula, too.

Next time you step outside and look at the Orion constellation, notice its three belt stars, and the sword hanging from his belt. The middle star in the sword looks just like William Herschel’s description of two centuries ago: an unformed fiery mist, the chaotic material of future suns.

That’s the Orion Nebula.

You can learn all about NASA’s missions at

And that’s all for this month. I’m Jane Houston-Jones. See you next year!

› View Vodcast