365 Days of Astronomy - Weekly Edition

Before we discovered other planets, our Solar System seemed like a perfectly reasonable template for everywhere. But now we see massive planets close to their stars, which leads you to the question, how does it all get there. Do the planets form in place or do they migrate around?

Things used to be so simple. Comets were snowballs from the outer Solar System, and asteroids were rocks from the inner Solar System. But now everything's all shades of grey. Astronomers have found asteroids that behave like comets and comets that behave like asteroids.

Once again, another place where the Universe is going to make this difficult for us. Proving, once and for all that there's alien life on another world. It should be straightforward, look for biosignatures, but it looks like there are natural sources that could explain almost any chemical we could hope to search for.

Our series on Universe weirdness marches on. This week we take a look at the habitable zone, and how things aren't as simple as we thought.

Our series on Universe weirdness continues, this time we learn how astronomers are struggling to make sense of the age of the Universe.

Just when the Universe was starting to make sense, the cosmos throws a curve ball at us. Astronomers have been trying to accurately measure the expansion rate of the Universe as far back as Hubble. It's been tough to nail down, and now astronomers are starting to figure out why.

As astronomers started to discover planets orbiting other stars, they immediately realized that their expectations would need to be tossed out. Hot jupiters? Pulsars with planets? We're now decades into this task, and the Universe is continuing to surprise us.

How old are Saturn's rings? They could be brand new, or they could be as ancient as the Solar System itself. Planetary scientists thought they knew the answer thanks to new data from Cassini, but new ideas are calling even that into question.

Thanks to all the work from Hayabusa 2 and OSIRIS-REx, astronomers are getting a much better look at the smaller asteroids in the Solar System. It turns out, they're piles of rubble... but fascinating piles of rubble. Let's talk about what we've learned so far.

We took a hiatus this summer, but SpaceX sure didn't, with the tests of the Starhopper prototype. Today we're going to talk about the revolution in reusable rocketry and quest to build a fully reusable two-stage rocket.

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Astronomy Cast will be on hiatus for July and August. Don't worry, we'll be back in September, and we might just have surprises for you all along this summer! Don't forget you can still catch Pamela with Daily Space, rocket launches and specials on CosmoQuest's Twitch channel, and you can find all the space news and videos from Fraser at Universe Today! We usually record Astronomy Cast every Friday at 3:00 pm EDT / 12:00 pm PDT / 19:00 UTC. You can watch us live on here on AstronomyCast.com, or the AstronomyCast YouTube page.

Relativity is used in more day to day situations than you may realize. In this episode, we will count (some of) the ways. This episode is brought to you live from the All-Stars Star Party in Indian Wells, California.

It's summertime, and time for our annual Astronomy Cast hiatus. But that doesn't mean that the astronomy adventure has to end. Today we'll give you some tips and tricks for astronomy summer adventures.

Last week we talked about some ancient south African astronomy, so this week we'll talk about the state of modern astronomy in the southern part of Africa, which happens to be a great place with nice dark skies and a great view into the heart of the galaxy.

Let's move to another continent this week, and look at the astronomy that was going on in southern Africa in ancient times.

Last week we talked about how well the indigenous Australians followed the night sky. Well, it turns out, Australia is still an amazing place for astronomy. There are so many powerful observatories in Australia, and even more in the works.

This week, we focus on the archaeoastronomy of another part of the world, this time from the indigenous people of Australia. Another group of people whose lives depended on knowing what was happening in the sky from season to season.

South America, especially the Atacama Desert in Chile has become one of the best places in the world to put a telescope. It's dry, high, and the nights are clear. Today we'll talk about the monster telescopes already in operation in this region, and the big ones coming soon.

The Andes mountains in South America are a hotspot of astronomy today, but ancient peoples knew it was a great place for astronomy and lived their lives in tune with the night sky. Today we'll learn all about what they knew, and how they mapped the movements of the stars and planets.

Last week we talked about the ancient astronomy of the American Southwest. But this is actually Pamela's stomping grounds, and she's spent many a night perched atop mountains in this region staring in the night sky with gigantic telescopes. How does astronomy get done in this region today?

Ancient peoples had no light pollution, and they knew the night skies very well. In fact, they depends on them to know when to plant and when to harvest. Today Pamela talks about the archeoastronomical sites of the American Southwest.

Today, of course, we're going to talk about the announcement from the Event Horizon Telescope and the first photograph of a black hole's event horizon.

Even though they might be scattered around our planet, astronomers have way to come together to work out issues that face their entire field of study. It's called the International Astronomical Union, and they're the ones who work out the new names for stars, and sometimes de-planet beloved Kuiper Belt Objects.

We learned how to figure out the ages of objects in the Solar System, now we push out into the deeper Universe. What about stars, galaxies, and even the Universe itself? How old is it? This episode is part 3 of a series.

Today we push our aging curiosity out into the Solar System to ask that simple question: how old is it and how do we know? What techniques do astronomers use to age various objects and regions in the Solar System? This is part two of a series.

People always want to know how old everything is. And more specifically, they want to know how we know how old everything is. Well, here at Astronomy Cast, it's our job to tell you now only what we know, but how we know what we know. And today we'll begin a series on how we know how old everything is. This is part one of a double episode.

Recorded during the Astrotour to Costa Rica, Fraser talks to Dr. Paul Matt Sutter about the nature of dust and BICEP 2's claim of discovering primordial gravitational waves.

We always focus on the missions, but there's an important glue that holds the whole system together. The Deep Space Network. Today we're going to talk about how this system works and how it communicates with all the spacecraft out there in the Solar System.

This is our second episode in a two part series where we look at Transients in astronomy. In last week's episode, we talked about things that change here in our own Solar System. Now we'll talk about everything else in the Milky Way and beyond.

Astronomers have found that sometimes the Universe changes. Things move, things explode, things get brighter or dimmer. In fact, knowing this has helped astronomers discover some very important aspects of the Universe. Today we begin a two part series on Transients and their role in astronomy.

We always say the Universe is trying to kill us. But there was this one time, when the Universe used our own fear of nuclear attack against us, nearly setting off a global nuclear war. Nice try Universe, we're on to you now.

One of the most influential astronomers in the 20th Century was Fritz Zwicky. He had his hand in the discovery of dark matter, gravitational lensing, supernovae and neutron stars. And he also worked on a few more controversial ideas like, uh, tired light. Let's learn more about Zwicky.

It's cold right now. Okay, fine, here on Vancouver Island, it's actually pretty warm. But for the rest of Canada and big parts of the US, it's terrifyingly cold. Colder than Mars or the North Pole cold. This is all thanks to the break up of the polar vortex. What are polar vertices, how do they form, and where else to we find them in the Solar System?

Space is a hostile environment in so many ways. But one of its worst features is the various kinds of radiation you can find. When astronauts go back beyond the protective environment of the Earth's magnetosphere, what are the various kinds of radiation they'll encounter. And is there anything we'll be able to do about it?

As we send rovers and landers to other worlds, we have to think about the tiny microbial astronauts we're sending along with us. In fact, NASA is so concerned about infecting other worlds that it has established the planetary protection protocols. Just to be safe.

The Sun. It's a big ball of fire, right? Apparently not. In fact, what's going on inside of the Sun took us some time and knowledge of physics to finally figure out: stellar fusion. Let's talk about the different kinds of fusion, and how we're trying to adapt it to generate power here on Earth.

Finding planets is old news, we now know of thousands and thousands of the places. But the terrible irony is that we can only see a fraction of the planets out there using the traditional methods of radial velocity and transits. But the new telescopes will take things to the next level and image planets directly.

We did it, we made it through 2018 in space. Now let’s look forward to the incredible launches, discoveries and astronomical events happening in 2019.

2018 was an incredible year in space news. Rockets launched, landers landed, spacecraft were born and died. We learned tremendous new things about Universe around us, and today we're here to look back fondly over the last 12 months to review the year in space that was.

The technology of 3D printing is taking off. From tiny home-based 3D printers to larger manufacturing. And of course, 3D printing is going to space with the International Space Station and beyond.

We did it, we made it to the end of another year. Once again it's time to wonder what gifts to get your beloved space nerds. We've got some suggestions. Some are brand new this year, others are classics that we just can't help but continue to suggest. Let's get into it.

Ion engines are a mainstay of science fiction, featured in both Star Trek and Wars. But this is a very real technology, successfully used on several missions out there in the Solar System right now. How do they work and what are the limits?

Did you hear that astronomers from Harvard think that the interstellar asteroid Oumuamua was actually an alien solar sail? Is it aliens? Of course it's not aliens. But some day, it'll actually be aliens.

We're always interested in the surface features of the planets and moons in the Solar System, but that's only skin deep. It turns out, these worlds have an interesting inner life too. Thanks to the science of seismology, we can peer into our planet and learn how it works... inside. And we're about to take that technology to Mars.

To really study something, you want to reach out and touch it. But what can you do if you're separated by a huge distance? You reach out with electromagnetic or sound waves and watch how they bounce back. Thanks to radar, sonar and lidar.

The Earth looks like a perfect sphere, but down here on the surface we see that there are mountains, rivers, oceans, glaciers, all kinds of features with different densities and shapes. Scientists can map this produce a highly detailed gravity map of our planet. And it turns out, this is very useful for other worlds too.

How do you know what something is made of if you can't reach out and touch it? How do we know what planets lights years away have in their atmosphere? What about the rocks all around Curiosity? Or the geysers coming out of Europa and Enceladus? Scientists have a few handy tricks.

We're not learning that the vast majority of potentially habitable worlds out there are actually icy moons like Europa and Enceladus. Good news, there are hundreds, if not thousands of times more of them than worlds like Earth. Bad news, they're locked in ice. What have we learned about water worlds and their potential for habitability?

Welcome to episode 500 of Astronomy Cast. To celebrate this momentous occasion, we're going to look back 500 years into the past to see what we learned about the Universe. And then we're going to look 500 years into the future. Astronomy Cast celebrated their 500th episode on Sept 15-16, 2018. We broadcasted from our celebration, in front of a live audience! And we debuted our new theme music by composer, fan and friend David Joseph Wesley!