Astronomy Cast

544: Weird Issues: Biosignatures Astronomy Cast 544: Weird Issues: Biosignatures by Fraser Cain & Dr. Pamela Gay 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.

Got clear skies? Go out tonight and catch the Orionids Meteor shower, a storm of falling stars generated by Halley's comet. Later this week, we'll see aurora like those that will one day be predicted by the ESA Solar Probe. We also have an update on the Mars 2020 rover.

543: Weird Issues: The Habitable Zone Astronomy Cast 543: Weird Issues: The Habitable Zone by Fraser Cain & Dr. Pamela Gay 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.

542: Weird Issues: The Age of the Universe Astronomy Cast 542: Weird Issues: The Age of the Universe by Fraser Cain & Dr. Pamela Gay Our series on Universe weirdness continues, this time we learn how astronomers are struggling to make sense of the age of the Universe.

541: Weird Issues: Expansion Rate of the Universe Astronomy Cast 541: Weird Issues: Expansion Rate of the Universe by Fraser Cain & Dr. Pamela Gay Just when the Universe was starting to make sense, the cosmos throws a curveball 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.

540: Weird Issues: How Do (or Don't) Planets Form? Astronomy Cast 540: Weird Issues: How Do (or Don't) Planets Form? by Fraser Cain & Dr. Pamela Gay 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.

539: Weird Issues: Why We Don't Know the Age of Saturn's Rings Astronomy Cast 539: Weird Issues: Why We Don't Know the Age of Saturn's Rings by Fraser Cain & Dr. Pamela Gay 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.

538: Asteroids: Rubble piles of the Solar System Astronomy Cast 538: Asteroids: Rubble piles of the Solar System by Fraser Cain & Dr. Pamela Gay 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.

537: Reusable Rocket Revolution Astronomy Cast 537: Reusable Rocket Revolution by Fraser Cain & Dr. Pamela Gay 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.

Please help us keep bringing you content by going to http://survey.libsyn.com/astronomycast and filling out the survey, so Libsyn can find us sponsors for Astronomy Cast!

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.

536: Everyday Relativity Astronomy Cast 536: Everyday Relativity by Fraser Cain & Dr. Pamela Gay 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.

535: Astronomy-Related Things To Do This Summer Astronomy Cast 535: Astronomy-Related Things To Do This Summer by Fraser Cain & Dr. Pamela Gay 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.

534: Modern South African Astronomy Astronomy Cast 534: Modern South African Astronomy by Fraser Cain & Dr. Pamela Gay You know the drill now. Last week we talked about ancient south African astronomy, and so this week we'll talk about the modern state of astronomy in the southern part of Africa, which happens to be a great place with nice dark skies and a perfect view into the heart of the galaxy.

533: Indigenous South African Astronomy Astronomy Cast 533: Indigenous South African Astronomy by Fraser Cain & Dr. Pamela Gay Let's move to another continent this week, and look at the astronomy that was going on in southern Africa in ancient times.

532: Modern Astronomy of Australia Astronomy Cast 532: Modern Astronomy of Australia by Fraser Cain & Dr. Pamela Gay 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.

531: Australian Indigenous Astronomy Astronomy Cast 531: Australian Indigenous Astronomy by Fraser Cain & Dr. Pamela Gay 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.

530: Astronomy of the Andes - Then and Now Pt. 2 Astronomy Cast 530: Astronomy of the Andes - Then and Now Pt. 2 by Fraser Cain & Dr. Pamela Gay 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.

529: Astronomy of the Andes - Then and Now Pt. 1 Astronomy Cast 529: Astronomy of the Andes - Then and Now Pt. 1 by Fraser Cain & Dr. Pamela Gay 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.

528: Modern Astronomy of the American Southwest Astronomy Cast 528: Modern Astronomy of the American Southwest by Fraser Cain & Dr. Pamela Gay 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?

527: Ancient Astronomy of the American Southwest Astronomy Cast 527: Ancient Astronomy of the American Southwest by Fraser Cain & Dr. Pamela Gay 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.

526: Event Horizon Telescope and the Black Hole at M87 Astronomy Cast 526: Event Horizon Telescope and the Black Hole at M87 by Fraser Cain & Dr. Pamela Gay 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.

525: 100 Years of the International Astronomical Union Astronomy Cast 525: 100 Years of the International Astronomical Union by Fraser Cain & Dr. Pamela Gay 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.

524: Judging Age & Origins, part 3 - Beyond Our System Astronomy Cast 524: Judging Age & Origins, part 3 - Beyond Our System by Fraser Cain & Dr. Pamela Gay 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.

523: Judging Age & Origins, Pt. 2 Across the Solar System Astronomy Cast 523: Judging Age & Origins, Pt. 2 Across the Solar System by Fraser Cain & Dr. Pamela Gay 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.

522: Judging Age & Origins, part 1 - Earth Rocks Astronomy Cast 522: Judging Age & Origins, part 1 - Earth Rocks by Fraser Cain & Dr. Pamela Gay 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.

Bonus: Dust with Dr. Paul Sutter Astronomy Cast Bonus: Dust with Dr. Paul Sutter by Fraser Cain & Dr. Pamela Gay 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.

521: The Deep Space Network Astronomy Cast 521: The Deep Space Network by Fraser Cain & Dr. Pamela Gay 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.

520: Transients: What They Are and Why They Matter, Part 2 Astronomy Cast 520: Transients: What They Are and Why They Matter, Part 2 by Fraser Cain & Dr. Pamela Gay

519: Transients: What They Are and Why They Matter Astronomy Cast 519: Transients: What They Are and Why They Matter by Fraser Cain & Dr. Pamela Gay

518: When the Universe tried to Declare War Astronomy Cast 518: When the Universe tried to Declare War by Fraser Cain & Dr. Pamela Gay

517: Fritz Zwicky and the Zwicky Transient Facility Astronomy Cast 517: Fritz Zwicky and the Zwicky Transient Facility by Fraser Cain & Dr. Pamela Gay

516: Polar Vortices Astronomy Cast 516: Polar Vortices by Fraser Cain & Dr. Pamela Gay

515: Space Radiation Astronomy Cast 515: Space Radiation by Fraser Cain & Dr. Pamela Gay

514: Planetary Protection Protocols Astronomy Cast 514: Planetary Protection Protocols by Fraser Cain & Dr. Pamela Gay

513: Stellar Fusion Astronomy Cast 513: Stellar Fusion by Fraser Cain & Dr. Pamela Gay

512: Direct Imaging of Exoplanets Astronomy Cast 512: Direct Imaging of Exoplanets by Fraser Cain & Dr. Pamela Gay

511: Predictions for 2019 Astronomy Cast 511: Predictions for 2019 by Fraser Cain & Dr. Pamela Gay

510: 2018 - Year in Review Astronomy Cast 510: 2018 - Year in Review by Fraser Cain & Dr. Pamela Gay

509: Fiction to Fact: 3D Printers Astronomy Cast 509: Fiction to Fact: 3D Printers by Fraser Cain & Dr. Pamela Gay

508: 2018 Holiday Gift Guide Astronomy Cast 508: 2018 Holiday Gift Guide by Fraser Cain & Dr. Pamela Gay

507: From Fiction to Fact: Ion Drive Astronomy Cast 507: > From Fiction to Fact: Ion Drive by Fraser Cain & Dr. Pamela Gay

506: It's not Aliens, Unless it's Aliens Astronomy Cast 506: It's not Aliens, Unless it's Aliens by Fraser Cain & Dr. Pamela Gay

505: Seismology Astronomy Cast 505: Seismology by Fraser Cain & Dr. Pamela Gay

504: Radar, Lidar & Sonar Astronomy Cast 504: Radar, Lidar & Sonar by Fraser Cain & Dr. Pamela Gay

503: Gravity Mapping Astronomy Cast 503: Gravity Mapping by Fraser Cain & Dr. Pamela Gay

502: No Touching: Determining Composition of Worlds Remotely Astronomy Cast 502: No Touching: Determining Composition of Worlds Remotely by Fraser Cain & Dr. Pamela Gay

501: Water Worlds Revisited Astronomy Cast 501: Water Worlds Revisited by Fraser Cain & Dr. Pamela Gay

500: Live Celebration! Astronomy Cast 500: Live Celebration! by Fraser Cain & Dr. Pamela Gay

499: What is the proposed Hubble-Lemaitre Law? Astronomy Cast 499: What is the proposed Hubble-Lemaitre Law? by Fraser Cain & Dr. Pamela Gay