Podcaster: Pamela Quevillon
Title: Cloudy with a Chance of Star Birth
Organization: Speak Easy Narration
Link : http://speakeasynarration.com ; http://www.unawe.org/kids/unawe1333/
Description: Space scoop, news for children. There’s no atmosphere in space. This means that there is no weather; no cool breeze, no torrential rainfall and definitely no snow…but there are clouds.
Feature image credit: ESO
Bio: Pamela Quevillon is a voice actress who most often lends her voice to science and science fiction content. You can find her work on the “Escape Pod” and “365 Days of Astronomy”, as well as on her site
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Transcript:
Hello and welcome to 365 Days of Astronomy for Saturday July 20. In this episode, we bring you another installment of our space scoop series from Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.Learn more at unawe.org
This episode is a story of
Cloudy with a Chance of Star Birth
This colourful object is NGC 6559 a star-forming region containing both emission nebulae (red) and reflection nebulae (blue). Credit: ESO
There’s no atmosphere in space. This means that there is no weather; no cool breeze, no torrential rainfall and definitely no snow…but there are clouds. Nebulae are clouds of gas and dust in space. ‘Nebula’ is actually the Latin word for ‘cloud’. These clouds come in many different varieties: some are the remains of dead stars, while others are areas of vigorous star birth, like this one. In fact, two different types can be seen in this striking new image: emission nebulae and reflection nebulae.
This colourful object is called NGC 6559. It is mainly made up of hydrogen, the raw material needed to form stars. When an area inside a nebula like this gathers enough material, it begins to collapse under its own gravity. It grows hotter and hotter until finally, nuclear fusion begins. This means that the hydrogen atoms ‘fuse’ together to form helium atoms. This process releases energy, which makes the star shine. Thus, a new star is born.
These brilliant new stars are born deep inside dust clouds, which obscure them from our eyes. However, they shine hot and bright within their gassy cocoons and pass on energy to the hydrogen gas around them in the nebula, causing it to shine. This is how the glowing, red threadlike cloud seen near the centre of this image was created. This is known as an emission nebula.
But NGC 6559 is not made of only hydrogen gas. It also contains solid particles of dust made from materials such as carbon and iron. The bluish patch next to the red emission nebula shows light from recently formed stars being scattered—in other words, reflected in many different directions—by these tiny particles. This is known as a reflection nebula.
Cool Fact: When starlight hits the dust particles in a reflection nebula such as this one, the light is scattered in all directions. Blue light scatters much easier than light of other colours because it travels as shorter waves. (Learn more about light waves here.) This is why reflection nebulae often appear blue.
Clouds in space are nothing like clouds on earth. If you float in a cloud in space, you will still be in a very empty place, and you won’t even notice the beautiful color of the gas you are floating in. On Earth, clouds are very dense, and over just a few meters, there can be enough water molecules that the cloud appears solid and opaque, and we can’t see through the cloud at all. Space clouds, however, only appear opaque because they are many light years across! From Earth, we see these clouds at such a great distance, that they appear small and dense, but that is just an illusion.
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by the New Media Working Group of the International Year of Astronomy 2009. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. 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. In the new year the 365 Days of Astronomy project will be something different than before….Until then…goodbye.