The final month of the International Year of Astronomy wraps up with an exploration of one of the most recognizable constellations: Orion.


Jane Houston-Jones: What's Up for December.

Title - Orion Nebula
Jane Houston-Jones: 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.

Title - Galileo Galilei
Jones: Galileo observed and sketched the Orion constellation and even the small grouping of stars in The Trapezium region of the Orion Nebula.

Title - Stars observed by Galileo in The Trapezium (black dots)

Jones: But he never wrote about or sketched the nebula itself. No other early astronomers did either.

Title: Giovanni Battista Hodierna
Jones: An observation from 1654 shows not only the three stars Galileo saw, but also the fuzzy patch which we know as the Orion Nebula.

Title - Christian Huygens
Jones: 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

Title - Protoplanetary Disks
Jones: protoplanetary disks are forming from gas and dust.

Title - Dust Cloud (disk). Star.
Jones: Solar systems like our own are formed from disks like these.

The stellar winds from stars create bubbles and arcs.

Title - bubble. arc.

Title - bow shock
Jones: Bow shocks.

And a huge deep bowl.

Title - bowl

Dark pillars of gas

Title - pillars of gas
Jones: are found in the outer layers. And cool brown dwarfs

Title - brown dwarfs
Jones: lie within the nebula, too.

Title - Looking Southeast. 8:00 pm. December 15. Orion.
Jones: Next time you step outside and look at the Orion constellation, notice it's three belt stars.

Title - Belt
Jones: And the sword hanging from his belt.

Title - Sword

Jones: 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.

Title - You can learn about NASA's missions at
Jones: You can learn all about NASA's missions at

Title - Thanks to the following for submitting images: Morris Jones, Ian Sharp
Jones: And that's all for this month. I'm Jane Houston-Jones. See you next year!

Title - NASA, Jet Propulsion Laboratory, California Institute of Technology
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