Podcaster: Richard Drumm
Title: Space Scoop: The Tale of Two Medusas
Organization: 365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1522/
Description: Space scoop, news for children.
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is 365 Days of Astronomy. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Today’s story is…
The Tale of Two Medusas
A famous, ancient Greek story tells the tale of a beautiful golden-haired lady named Medusa. Medusa was as vain as she was beautiful, which eventually got her into trouble with the powerful goddess Athena, who thought that SHE was the most beautiful goddess. As a punishment for her vanity, Athena turned each of Medusa’s beautiful golden locks of hair into a poisonous snake.
Are you wondering what this tale has to do with Astronomy? Well, the cosmic cloud of gas and dust in the picture in today’s album artwork is called Abell 21 and is located in the constellation Gemini. It’s also called the Medusa Nebula because astronomers think the smoky curtains of gas look like the writhing snakes on Medusa’s head. What do you think? Maybe it’s just that it looks like golden hair.
Hmmmm…
The similarities between these two stories, snakes & blonde hair, don’t end there. The snake-like gas from this cosmic cloud was once tucked away inside a beautiful golden star, similar to our Sun. But, like Medusa’s golden locks, the star didn’t stay that way.
As the star grew older it also grew larger. When the star was a few billion years old, it spent some millions of years expanding in size, the expansion driven by the intense heating of the core as it ran out of hydrogen fuel. It finally became a large red giant star, the gas in the outer atmosphere of the star was literally pushed out of the red giant’s gravity well by the incredible heat.
If you can’t stand the heat, they say, get out of the kitchen, so that’s what the star’s atmosphere did, it left! This material was lost into space where it blossomed into the colorful shape we see in this image from ESO’s Paranal Observatory. We call these clouds planetary nebulae, PNs for short. Not because they are planets, but because they looked a little like the planets did in the telescopes of a couple hundred years ago.
The intense ultraviolet light from the stars’s exposed core— it’s now what we call a white dwarf — causes the gas clouds to fluoresce, the colors revealing the chemical elements that it’s composed of. Red is hydrogen and the green is doubly ionized oxygen. Take a deep breath. This is where we get the oxygen we are breathing. PNs are good for life!
For tens of thousands of years this planetary nebula will surround the white dwarf remains of its parent star. But this stage makes up just a tiny portion of the star’s total lifetime. The white dwarf will slowly cool till it becomes a black dwarf, a dead stellar cinder.
Hey, Here’s A Cool Fact
The white dwarf will take something like a trillion years to cool enough to be called a black dwarf. Then the black dwarf will cool to absolute zero after uncounted trillions upon trillions of years have passed. I did say it was a cool fact didn’t I? That black dwarf star will watch the universe expand and stars die one by one until there are no stars or galaxies visible in the sky at all. Of course there will be no eyes present then to notice the darkness. So there’s that… A cold future awaits the universe, I’m afraid. But for now we have pretty pictures to look at and oxygen to breathe!
Thank you for listening to 365 Days of Astronomy!
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by NUCLIO. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we celebrate cosmic light as light is our info messenger in the universe. Join us and share your story to celebrate the International Year of Light. Until tomorrow! Goodbye!