Podcast: Cosmological Constant

In order to allow for a static Universe, Albert Einstein introduced the concept of the Cosmological Constant Lambda to make the math work out. Once it was discovered that the Universe was actually expanding, he threw the number out calling it his “biggest blunder.” But thanks to dark energy, the Cosmological Constant is back.

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“Cosmological Constant” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

Astronomy Cast Ep. 279: The Hubble Constant


When Edwin Hubble observed that distant galaxies are speeding away from us in all directions, he discovered the reality that we live in an expanding Universe. Hubble worked to calculate exactly how fast this expansion is happening, creating the Hubble constant – which astronomers continue to refine and reference in their research.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Hubble Constant” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:
Continue reading “Astronomy Cast Ep. 279: The Hubble Constant”

Podcast: The Christmas Star

Adoration of the Magi

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With Christmas just around the corner, we thought we’d investigate a mystery that has puzzled historians for hundreds of years. In the bible, the birth of Jesus was announced by a bright star in the sky that led the three wise men to his birthplace. What are some possible astronomical objects that might look like such a bright star in the sky? And were there any unusual events that happened at that time?

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The Christmas Star – Transcript and show notes.

Podcast: Robots in Space

Mars Rover. Image credit: NASA/JPL

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Space is totally inhospitable. If the freezing temperatures don’t get you, the intense radiation will kill you. Or the vacuum, or the lack of breathable atmosphere, or meteoroid impacts. Well… you get the idea. That’s why most space exploration is done by hardy robots. They don’t need to eat, drink or breathe. They get their energy from the Sun, and they’ve proven they’ve got the right stuff to explore every planet and major moon in the Solar System. Let’s hear it for the space robots.

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Robots in Space – Transcript and show notes.

Podcast: Distance in Space, Changing Earth’s Orbit, and Different Sized Stars

Betelgeuse. Image credit: Hubble

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This week we find out the distance between Betelgeuse and Bellatrex, how astronomers measure distance between objects, the possibility that an object could mess up the Earth’s orbit, and the reason for different sizes of stars. If you’ve got a question for the Astronomy Cast team, please email it in to [email protected] and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.

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Distance in Space, Changing Earth’s Orbit, and Different Sized Stars – Transcript and show notes.

Podcast: Sky Surveys

Sloan Digital Sky Survey

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In the old days, astronomers had to beg for telescope time. They’d put together a proposal, convince observatories to gather data for them, crunch that data and release the results. No telescope, no results. But everything’s different now. Fleets of robotic telescopes constantly scan the skies, building up a vast database of raw data about the Universe. Anyone who wants can access the information through the Internet, download what they need to do real science. No telescope necessary. Let’s look at the development of sky surveys, and how they’re changing how astronomy gets done.

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Sky Surveys – Transcript and show notes.

Podcast: Time

Ancient Chinese sundial.

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Today, time rules our lives. We live each day with the moments broken up into hours, minutes and seconds. We never seem to have enough time. But can you imagine not being able to tell time at all, where the movements of the Sun and the stars was the only way to know what time it was? Let’s learn about the history of time, methods of telling time, and Einstein’s historic discovery that time isn’t as fixed as we thought it was.

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Time – Transcript and show notes.

Podcast: Molecules in Space

Molecules in Space

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As part of her trip to England, Pamela had a chance to sit down with Oxford astrophysicist Chris Lintott and record an episode of Astronomy Cast. From the first stars to the newest planets, molecules and the chemistry that allows them to form affects all aspects of astronomy. While most astronomers group molecules into three bins of hydrogen, helium and everything else, there are a few who do proper chemistry by studying the sometimes complex molecules that form between the stars.

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Molecules in Space – Transcript and show notes.

Podcast: The Moon, Part 3: Return to the Moon

Altair Lander. Image credit: NASA

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It’s time for a third lunar chapter. We’ve talked about the physical characteristics of the Moon, and the exploration. Now we’re going to talk about the plans to return to the Moon. From the upcoming lunar reconnaissance orbiter to the plans to have humans set foot on the Moon again, for the first time in more than 50 years.

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The Moon, Part 3: Return to the Moon – Transcript and show notes.

Podcast: Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear

Artist impression of the Milky Way.

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This week we explore galactic spiral arms, seismic quakes on the Sun, and our picks for astronomy gear. If you’ve got a question for the Astronomy Cast team, please email it in to [email protected] and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.

Click here to download the episode.

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Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear – Transcript and show notes.