Ep. 476: The Overview Effect

After they’ve been to space, many astronauts report that seeing the world from above has given them a totally new perspective on humanity and the state of our planet. It’s called the Overview Effect. Today we’ll talk about this, and what this perspective can teach us all.

Ep. 459: Arecibo Observatory

The iconic Arecibo Radio Observatory has been a mainstay in science and science fiction. This Puerto Rico-based radio telescope was already in an uncertain level of funding. But now with the damage from Hurricane Maria, it might be shut down forever.

Ep. 418: Error 418 – I'm a Teapot!

One of the most familiar asterisms in the night sky is the Teapot, in Sagittarius. Today we’re going to talk about that and have a bonus conversation about Bertrand Russell’s Teapot Argument.

Ep. 398 – Seeing Things: Emitting, Reflecting, Ionizing Light

Astronomers gather electromagnetic radiation with the telescopes: mostly visible light. But sometimes they’ve got to be clever about where they look for these elusive photons. Light can get emitted, absorbed, reflected, and each method tells astronomers a little more about what they’re looking at.

Ep 386: Orbiting Observers

The atmosphere keeps us alive and breathing, but it really sucks for astronomy. Fortunately, humanity has built and launched space telescopes that get above the pesky atmosphere, where the skies are really clear. Let’s take a look at the past, current and future of orbital observation.

Ep. 384: Escaping Probes

The gravity of the Earth is a tough thing to escape, but breaking free from the gravity of the Sun is on a whole other level. But humans have achieved this amazing accomplishment, and right now there are several spacecraft leaving the Solar System and never coming back.

Ep. 380: The Limits of Optics

Astronomers rely on the optics of their instruments, and there are some basic limits that you just can’t avoid. Whatever we look at is distorted by the optics, in fact, a basic property of light means that we’ll never get perfect optics. Here’s why we can’t “magnify and enhance” forever.

Ep. 369: The Fizeau Experiment

Light is tricky stuff, and it took scientists hundreds of years to puzzle out what this stuff is. But they poked and prodded at it with many clever experiments to try to measure its speed, motion and interaction with the rest of the Universe. For example, the Fizeau Experiment, which ran light through moving water to see if that caused a difference.

Ep. 367: Spitzer does Exoplanets

We’ve spent the last few weeks talking about different ways astronomers are searching for exoplanets. But now we reach the most exciting part of this story: actually imaging these planets directly. Today we’re going to talk about the work NASA’s Spitzer Space Telescope has done viewing the atmospheres of distant planets.

Ep. 366: HARPS Spectrograph

Almost all the planet hunting has been done from space. But there’s a new instrument installed on the European Southern Observatory’s 3.6 meter telescope called the High Accuracy Radial velocity Planet Searcher which has already turned up 130 planets. Is this the future? Searching for planets from the ground?

Ep. 351: Asteroid Adventures

Astronomy Cast’s 2014/15 season begins! With Rosetta’s arrival at Comet 67/P, we’re about to see a comet up close and personal. What will it take to explore, exploit and enjoy the asteroids and comets hurtling around our Solar System. And how does science fiction have it all wrong?

Ep. 337: Photometry

There’s a lot you can learn by just staring at an object, watching how it changes in brightness. This is the technique of photometry, and it has helped astronomers discover variable stars, extra-solar planets, minor planets, supernovae, and much more.

Ep. 334: Chelyabinsk

Around this time last year a space rock crashed into the Earth above Chelyabinsk, Russia. It brightened the skies for hundreds of kilometers, broke windows and injured many people. Let’s look back at the event. What happened, and what did we learn?

Ep. 319: The Zodiac

Although the Zodiac is best known for astrology nonsense, it has a purpose in astronomy too. The constellations of the Zodiac define the plane of the ecliptic: the region where the Sun, Moon and planets appear to travel through the sky. What are the constellations of the Zodiac, and how do astronomers use them as way-points?

Ep. 317: Observatories

Have you ever wondered what it’s like to visit one of the big research observatories, like Keck, Gemini, or the European Southern Observatory? What’s it like to use gear that powerful? What’s the facility like? What precautions do you need to take when observing at such a high altitude?

Ep. 295: The Observable Universe

We understand our place in the Universe because of our direct observations. We can see the light that travelled billions of light years across space to reach us. This sphere of space is the observable universe; everything we can detect. But it’s really just a fraction of the larger, unobservable universe. Today, we’ll talk about both.

Ep. 294: The Arecibo Observatory

The mighty Arecibo Radio Observatory is one of the most powerful radio telescopes ever built – it’s certainly the larger single aperture radio telescope on Earth, nestled into a natural sinkhole in Puerto Rico. We’re celebrating the 50th anniversary of the construction of the observatory with a special episode of Astronomy Cast.

Ep. 256: Resolution

When it comes to telescopes, astronomers really just care about resolution: how much can you see? Your resolution defines how much science you can get done, and it depends on your gear, wavelength, and conditions. Putting a telescope in space really helps too.

Ep. 248: Carina Constellation

Time for another detailed look at a constellation; one of the most fascinating in the sky, but hidden to most of the northern hemisphere: Carina. Home to one of the most likely supernova candidates we know of: Eta Carinae. Let’s talk just about this constellation, how to find it, and what you can discover in and around it.

Ep. 245: Calendars

Our lives are ruled by calendars. And calendars are ruled by astronomy. As we near the end of 2011, and get ready to ring in the new year, let’s discover the astronomy underlying the days, weeks, months and years that segment our lives.

Ep. 234: Lunar Phases

The Moon is a stark reminder that we actually live in a Universe filled with stars and planets and moons. The changing phases of the Moon show us the relative positions of the Earth, the Sun and the Moon as they interact with one another. Let’s learn about the different phases, the geometry of the whole system, and some of the interesting science wrapped up with our fascination of our only natural satellite.

Ep. 227: The Big Dipper

We wanted to spend a few shows talking about some of the most recognizable constellations in the night sky. We’ve chatted about Orion the Hunter, but now we’re going to talk about the Big Dipper, also known as Ursa Major, or the Great Bear – apologies to our southern hemisphere listeners.

Ep. 224: Orion

Most people know how to find two constellations: the Big Dipper, and Orion the Hunter. You can teach a small child to find Orion, and at the right time of year, they’ll find it in seconds. There’s so much going on in this spectacular constellation, from the star formation in the Orion Nebula to mighty red supergiant Betelgeuse, ready to explode. Let’s learn about the history and science of the constellation Orion.

Ep. 160: Eclipses

Every now and then, the Moon destroys the Sun. Okay, not destroys, covers. Well, not really covers, but from here on Earth, sitting inside the shadow of the Moon, that’s what it sure looks like. These events are called eclipses, or more precisely, transits and occultations. They occur whenever one object passes in front of another from a 3rd perspective. They’re beautiful and exciting, and deliver a tremendous amount of science as well.

Episode 131: Submillimeter Astronomy

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.

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