Ep. 137: Large Scale Structure of the Universe

Evolution of the large scale structure of the Universe. Image credit: NASA

This week we’re going to think big. Bigger than big. We’re going to consider the biggest things in the Universe. If you could pull way back, and examine regions of space billions of light-years across, what would you see? How is the Universe arranged at the largest scale? And more importantly… why?

Ep. 137: Large Scale Structure of the Universe

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Ep. 136: Gamma Ray Astronomy

Artist impression of a gamma ray burst. Image credit: NASA

And now we reach the end of our tour through the electromagnetic spectrum. Last stop… gamma rays. These are the most energetic photons in the Universe, boosted up to incredible energies in the most violent places in the Universe. Gamma rays are tricky to catch, but they can reveal the most dramatic events in the Universe.

Ep. 136: Gamma Ray Astronomy

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Ep. 135: X-Ray Astronomy

Supernova remnant W49B, seen in X-rays and visible light.

We continue our journey through the electromagnetic spectrum with X-rays.  If you've ever broken a bone, you probably know how X-rays are most commonly used.  While doctors use X-rays to study the human body, and astronomers use X-rays to study some of the hottest places in the Universe. So let's put on our X-ray specs, and see what we can see.

Ep. 135: X-Ray Astronomy

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Ep. 134: Ultraviolet Astronomy

M81 in ultraviolet. Image credit: NASA

Our next visit in this tour through the electromagnetic spectrum is the ultraviolet. You can't see it, but anyone who's spent a day out in the hot sun without sunblock has sure experienced its effects. Ultraviolet radiation is associated with the birth of stars and some of the hottest places in the Universe.

Ep. 134: Ultraviolet Astronomy

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Ep. 133: Optical Astronomy

Hubble Space Telescope

Optical astronomy; now this is the kind of astronomy a human being was born to do. In fact, until the last century, this was the only kind of astronomy anybody ever did. Now we've got the whole electromagnetic spectrum to explore, but our heart still belongs to optical astronomy. Of course, with bigger telescopes, better optics and more sensitive detectors, even optical astronomy has come a long way.

Ep. 133: Optical Astronomy

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Ep. 132: Infrared Astronomy

James Webb telescope

Today we continue our unofficial tour through the electromagnetic spectrum, stopping at the infrared spectrum – you feel it as heat. This section of the spectrum gives us our only clear view through dusty material to see newly forming planetary systems and shrouded supermassive black holes. And infrared lets us look out to the most distant regions of the observable universe, when the first building blocks of galaxies came together.

Ep. 132: Infrared Astronomy
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Episode 131: Submillimeter Astronomy

Artist's impression of the ALMA array

Last week we examined the largest wavelength in the electromagnetic spectrum: radio. This week we get a little smaller… but not too small! And look at the next step in the spectrum, the submillimeter. Astronomers have only recently began exploiting this tiny slice of the spectrum, but the payoff has been huge.

Ep. 131: Submillimeter Astronomy
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Episode 130: Radio Astronomy

Green Bank Radio Telescope

Astronomers are very resourceful, when it comes to light, they use the whole spectrum – from radio to gamma rays. We see in visible light, but that's just a tiny portion of the spectrum. Today we're going to celebrate the other end of the spectrum; the radio end, where photons really stretch out their wavelengths.

Ep. 130: Radio Astronomy
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Ep. 129: Interferometry

ESO Very Large Array. Image credit: ESO

When it comes to telescopes, bigger is better. But bigger is more expensive. Way more expensive. To keep the costs reasonable while improving the sensitivity of their instruments, astronomers use an amazing technique called interferometry. Instead of building a single huge telescope, you can merge the light from several telescopes to act like a much larger telescope. It's a technique that has already revolutionized Earth-based observing – but just wait until it gets into space…

Ep. 129: Interferometry
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Ep. 128: Dust

Dark nebula in Orion.

You can't make a Solar System without a whole lot of dust. And that's the problem. This dust has blocked astronomers views into some of the most fascinating parts of the cosmos. It shields the galactic core, enshrouds newly forming stars and their planets, and blocks our view to churning supermassive black holes, actively feeding in distant galaxies. But new telescopes and techniques are allowing astronomers to peer through this dust, and see these events like never before.

Ep. 128: Dust
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