Astronomy Cast

Astronomy Cast Ep. 714: Orbital Resonances by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 25, 2024. Several of the planets and moons in the Solar System are in orbital resonance, orbiting in a geometric lockstep. And not just the Solar System, astronomers have found the same resonances in other star systems.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 713: Solar System Volcanoes by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 18, 2024. Last week was one of the most exciting meetings we’ve seen from the Lunar and Planetary Science Conference, with hundreds of announcements and discoveries from various missions. One theme kept coming up, the Solar System is more volcanically active than we thought. Today, we’ll explore volcanism on other worlds.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 712: How Peer Review Fails by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 11, 2024.   You’ve probably heard that the best kind of science is peer-reviewed research published in a prestigious journal. But peer review has problems of its own. We’ll talk about that today.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 711: NASA Innovative Advanced Concepts (NIAC) by Fraser Cain & Dr. Pamela Gay Streamed live March 4, 2024. NASA works on many missions using tried and true technology, but they also invest in creative ideas that could drive the future of space exploration. It’s called NASA’s Innovative Advanced Concepts or NIAC.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 710: NASA's Commercial Lunar Payload Services (CLPS) Program by Fraser Cain & Dr. Pamela Gay Streamed live on Feb 26, 2024. In the olden days, NASA developed its missions using a variety of in-house engineers and external suppliers. As more commercial companies are targeting the Moon, NASA is working with partners to deliver its payloads to the lunar surface. Today let’s talk about NASA’s Commercial Lunar Payload Program.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 709: Space Weapons by Fraser Cain & Dr. Pamela Gay Streamed live on Feb 19, 2024. [My apologies for Fraser’s audio dropouts. We’re not sure how it happened as it wasn’t happening at his studio. Audio is a black art, IMHO. Rich) Last week we learned that Russia might be planning nuclear weapons to take out satellites in space. What is the current and future possibility of weapons in space and what are the treaties designed to prevent them?   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit (rhymes with right) Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 708: What Goes Into Sample Return Missions From Asteroids & Comets? by Fraser Cain & Dr. Pamela Gay Streamed live Feb 12, 2024. Last week we talked about sample return missions from the Moon and Mars, but scientists have retrieved samples from other objects in the Solar System, including comets and asteroids. What does it take to return a piece of rock from space, and what have we learned so far?   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit ( rhymes with right) Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 707: What Goes Into A Sample Return Mission? Moon & Mars by Fraser Cain & Dr. Pamela Gay Streamed live on Feb 5, 2024. We’ve sent robots to other worlds, but the amount of science we can deploy to another planet can’t compare with the vast science labs we have on Earth. That’s why more and more missions are for a sample return, bringing pieces of alien worlds back to Earth, where we study them with proper equipment.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit ( rhymes with right) Jeanette Wink Siggi Kemmler Andrew Poelstra Brian Cagle David Truog Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 706: China’s Space Program by Fraser Cain & Dr. Pamela Gay Streamed live on Jan 30, 2024. We’re so familiar with NASA’s exploration efforts in space, but you might be surprised to learn that China launches almost as many rockets as the US. They’ve got their own space exploration program that could soon bring humans to the surface of the Moon. Let’s give a brief overview of China’s space exploration plans.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 705: Water Worlds - Looking For Life Beyond Earth by Fraser Cain & Dr. Pamela Gay Streamed live January 17, 2024. Wherever we find liquid water on Earth, we find life, so it makes sense to search for water across the Universe, and hopefully we can find evidence of life. But what about worlds which are completely covered in water, oceans hundreds of kilometers deep. Can there be too much water?   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 704: NASA's Juno Releases New Images by Fraser Cain & Dr. Pamela Gay Streamed live January 8, 2024. NASA’s Juno spacecraft has completed dozens of flybys of Jupiter, seeing the planet from many angles and delivering some of the most beautiful images we’ve ever seen of the Jovian world. Now it’s focusing in on Io, sending home images of the tiny volcanic world from just 1,500 km away. And the best is yet to come.   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 703: Solar Maximum of Doom? Maybe by Fraser Cain & Dr. Pamela Gay Streamed live on Dec 20, 2023. Solar cycle 25 is shaping up to be a doozy, with plenty of flares and coronal mass ejections blasting off the Sun. As the solar activity continues to rise, how are things shaping up?   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed Gerhard Schwarzer David Nicholas Cunningham THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 702: Moonshot 2024 - Go or No Go? by Fraser Cain & Dr. Pamela Gay Streamed live on Dec 11, 2023. With Artemis 1 completing its robotic flight around the Moon, we know that the SLS works. Next comes Artemis 2, with a crew of astronauts flying past the Moon. If that’s successful, we could see humans set foot on the Moon in December 2025. But there is a long list of challenges to consider that could delay things considerably. Go or no go for launch‽   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed Gerhard Schwarzer David Nicholas Cunningham THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 701: Space Science We Look Forward to in the Next 700 Episodes by Fraser Cain & Dr. Pamela Gay Streamed live on Dec 4, 2023. Last week we looked back at some of the ideas that science has changed its mind about. This week we look forward, into the future, at some of the big ideas that astronomers are making progress in. What space science are we looking forward to?   This video was made possible by the following Patreon members: Jordan Young BogieNet Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra David Truog Brian Cagle Ed Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 700: The Things We Got Wrong by Fraser Cain & Dr. Pamela Gay Streamed live on Nov 27, 2023. Astronomers talk about all the amazing discoveries they’re making but sometimes, it turns out, they were wrong. After decades and centuries of discoveries, how have they changed their minds?   This video was made possible by the following Patreon members: Jordan Young Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Ed BogieNet Brian Cagle David Truog Gerhard Schwarzer David Nicholas Cunningham THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 699: Holiday Gift Giving Ideas for Astronomy and Space Fans by Fraser Cain & Dr. Pamela Gay Streamed live on Nov 20, 2023. Just a warning, the holidays are rapidly approaching. It’s time, once again, to think about what to buy all the space nerds on your lists. Here’s what we like.   This video was made possible by the following Patreon members: Jordan Young Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Ed BogieNet Brian Cagle David Truog Gerhard Schwarzer David Nicholas Cunningham THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 698: Insights Into the Universe by Fraser Cain & Dr. Pamela Gay From Nov 5, 2023. How the time flies. It’s been over a year since JWST went operational, with other missions joining the fun. What new insights have we gained about the Universe thanks to these powerful new tools?   Recorded live during the 2023 Hangout-a-Thon on November 5.   This video was made possible by the following Patreon members: Jordan Young Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Ed BogieNet Brian Cagle David Truog Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 697: Mission Roll Call Part 6: The Outer Solar System and Beyond by Fraser Cain & Dr. Pamela Gay Streamed live November 4th, 2023.. Finally, we reach the end of our tour through the missions in the Solar System. Out beyond Mars, to Jupiter, the Kuiper Belt and Beyond.   This video was made possible by the following Patreon members: Jordan Young Stephen Veit Jeanette Wink Siggi Kemmler Andrew Poelstra Ed BogieNet Brian Cagle David Truog Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 696: Mission Roll Call Part 5: The Science at Mars by Fraser Cain & Dr. Pamela Gay Streamed live on Oct 30, 2023. Another week, another review of space missions in the Solar System. Today we set our sights on the red planet. What are all the active missions at Mars today?   This video was made possible by the following Patreon members: Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 695: Mission Roll Call Part 4: Lunar Exploration by Fraser Cain & Dr. Pamela Gay Streamed live on Oct 23, 2023. Our journey through missions continues, this time we focus on the Moon. There are many nations on the Moon, near the Moon, around the Moon, traveling to the Moon. It’s a lot. We’ll talk about it today.   This video was made possible by the following Patreon members: Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 694: Mission Roll Call Part 3: Sun, Mercury, and Venus by Fraser Cain & Dr. Pamela Gay Streamed live on Oct 16, 2023. Our journey through space missions continues. Now we move away from the Earth to the rest of the solar system. What’s out there orbiting, roving and flying on other worlds and in interplanetary space. Today we look inward and we’ll talk about the missions studying the Sun, Mercury and Venus.   Thank you to all of our patrons who allow us to do this! This week I'd like to thank Jeremy Kerwin, Stuart Mills, Slug!, Harold Bardenhogan, Matthew Horstman, Kimberly Reich, Georgie Ianov, Scott Bieber, Jim Schooler. Marco Yarasi, David Gates, Alex Cohen, Justin Proctor, Claudia Mastriani, Scott Cohen, Disastrina, Kinsaya Pianflinko, Mathias Hayden, The Big Squish Squash!, Tim Garish, Gregory Singleton, Tim McMackin, Jeff Wilson Cooper, Paul D Disney, Benjamin Mueller, Ninja Nick, Kenneth Ryan, Eran Segev, Scott Briggs and Bruce Amazine. Thank you all so much! 

Astronomy Cast Episode 693: Mission Roll Call, Part 2: Looking Outward from Earth by Fraser Cain & Dr. Pamela Gay Streamed live on Oct 9, 2023. Last week, we brought you up to speed on the spacecraft which are helping to study Earth from above. Many of our missions are in Earth orbit but looking outward to study the Universe. Today, we’ll talk about the missions close to home, helping us understand our place in the cosmos.   This video was made possible by the following Patreon members: Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 692: Mission Roll Call Part 1: Earth Orbit by Fraser Cain & Dr. Pamela Gay It’s time for another series! This time we’re gonna look at the missions that’re currently in place across the solar system. Today we’ll start with the key missions here on Earth, studying the planet from above and looking out into the Universe. 

Astronomy Cast Ep. 691: Jupiter’s Changing Red Spot by Fraser Cain & Dr. Pamela Gay Streamed live on Sep 25, 2023. Jupiter’s Great Red Spot is one of its most iconic features. First seen hundreds of years ago. Although it’s certainly long lasting, it’s been changing in size over the last few decades. Shrinking, changing in color. Is it fading away? And what can the changes tell us about storms on giant planets?

Astronomy Cast Ep. 690: Climate on Mars - From Ice Caps to Dust Storms by Fraser Cain & Dr. Pamela Gay Streamed live on Sep 18, 2023. We’ve looked at Earth’s changing climate, now let’s see what it’s like for another world: Mars. Much looks familiar, but some of it is totally alien, from ice caps of frozen carbon dioxide to planetary dust storms that can obscure the entire world from view.   This video was made possible by the following Patreon members: Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 689 - Our Warming World: 20 Years of Climate Science by Fraser Cain & Dr. Pamela Gay Streamed live on Sep 11, 2023. It’s official! June and July were the warmest we’ve seen since records began over a century ago. Fires are rampant across Canada, and we’re seeing record droughts around the world. Today we’re going to look at 20 years of climate science, how well does reality match up with the predictions.   This video was made possible by the following Patreon members: Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast - Hiatus Message by Fraser Cain & Dr. Pamela Gay Once again, we’ve reached the end of a season here on Astronomy Cast, and it’s time for the summer hiatus. See you in September!

Astronomy Cast Ep. 688: What’s Next? Looking Ahead to Season 17 by Fraser Cain & Dr. Pamela Gay Streamed live on Jun 26, 2023. Once again, we’ve reached the end of a season here on Astronomy Cast, and it’s time for the summer hiatus. But the Universe never takes a break. What can we expect to happen over the summer while we’re catching up on our reading, building our gardens and planning for Season 17?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 687: Prepping for the Moon by Fraser Cain & Dr. Pamela Gay We’re going back to the Moon. In the next few years humans will set foot on the Moon again, ideally this time to stay. But this will be different than the Apollo era, going to the scientifically fascinating, and difficult southern pole of the Moon. What needs to be done to prepare the way back to the Moon?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 686: Ice In The Shadows by Fraser Cain & Dr. Pamela Ga Streamed live on Jun 12, 2023. The permanently shadowed craters on the Moon are the focus of so much research. That’s because they seem to contain vast reserves of water ice. Water we could use for oxygen, propellant and so much more, but also, to help us understand where the Earth’s water came from.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela  

Astronomy Cast Ep. 685: Manufacturing In Space by Fraser Cain & Dr. Pamela Gay Streamed live on Jun 5, 2023. Launching satellites from Earth is counter-productive. You’ve got to make a satellite that can handle Earth gravity, then the brutal flight to space, then deployment in orbit. What if you could build your spacecraft in space?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Andrew Poelstra Brian Cagle David Truog BogieNet Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 684: Too Big, Too Soon: Massive Early Galaxies Defy Expectations by Fraser Cain & Dr. Pamela Gay Streamed live on May 29, 2023. One of JWST’s top jobs is to peer deeper into the Universe than ever before, watching as the first galaxies came together. Surprisingly, astronomers found galaxies that seemed much more mature than expected, much earlier than it was believed possible. What’s going on and what does it mean for cosmology?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Jeanette Wink Gerhard Schwarzer David BogieNet THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 683: Cosmic Dawn by Fraser Cain & Dr. Pamela Gay Streamed live on May 22, 2023. After the cosmic microwave background radiation was released, the Universe returned to darkness, cloaked in this clouds of primordial hydrogen and helium. Gravity pulled these vast clouds into the first stars, and then the first galaxies. This is Cosmic Dawn, and JWST will help us probe this mysterious time in the Universe.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Jeanette Wink Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 682: Ultra-Diffuse Galaxies & Dark Matter by Fraser Cain & Dr. Pamela Ga Streamed live on May 15, 2023. Astronomers first noticed the strange behaviors of rotating galaxies almost 100 years ago, suggesting there’s an invisible dark matter hold them together with gravity. Or maybe we just don’t understand how gravity works at the largest scales. Observations are much better now, and astronomers have found examples of galaxies that are almost entirely made of dark matter. Does this tell us anything?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Jeanette Wink Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela  

Astronomy Cast Ep. 681: Kilonovae by Fraser Cain & Dr. Pamela Gay Streamed live on May 7, 2023. In 2017, astronomers detected the gravitational waves and electromagnetic radiation from colliding neutron stars. This had been long theorized as one of the causes of a certain type of gamma-ray burst. By studying the event and its afterglow, astronomers have learned a tremendous amount about the formation of the heaviest elements in the Universe.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Jeanette Wink Gerhard Schwarzer David THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 680: Rogue Black Holes by Fraser Cain & Dr. Pamela Gay Streamed live on May 1, 2023. Last week we talked about rogue stars. This week we’re going to take things up a notch and talk about an even more extreme event. Rogue black holes. Astronomers recently discovered a supermassive black hole on an escape trajectory, leaving newly forming stars in its wake. It’s wonderful, terrible, nightmare fuel. Fraser’s rogue SMBH article: The original paper:   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 679: High(per) Velocity Stars by Fraser Cain & Dr. Pamela Gay Streamed live on Apr 24, 2023. Most stars in the Milky Way are trapped in here with us, doomed to orbit around and around and around. But a few have found a way out, an escape into the freedom of intergalactic space. How do stars reach escape velocity, never to return?   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Jeannette Wink Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 678: World Building: Planet Formation, Growth & Ejection by Fraser Cain & Dr. Pamela Gay Streamed live on Apr 17, 2023. Okay sci-fi writers, today we’re going to give you a guided tour of building planets. How they form, how they grow, and how things can go horribly horribly wrong. [Editor’s Note: Google HL Tau, click on the Wikipedia link and see planets forming!]   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Jeannette Wink Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 677: The Answer is Always Dust by Fraser Cain & Dr. Pamela Gay Streamed live on Apr 10, 2023. Whenever astronomers discover something surprising, the answer often turns out to be dust. Dust obscuring our view, dust changing the polarity, dust warming things up, dust cooling things down. It’s always dust. Until it isn’t.   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Jeannette Wink Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 676: Other Things With Rings by Fraser Cain & Dr. Pamela Gay Streamed live on Apr 3, 2023. We’ve spent a lot of time gushing about Saturn’s rings, but there are other places with ring systems. And not just Jupiter and the ice giants, but asteroids, dwarf planets, centaurs and even exoplanets. Today let’s gush about them!   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Jeannette Wink Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 675: Exotic Forms of Ice by Fraser Cain & Dr. Pamela Gay Ice is ice, right? You know, what you get when water freezes. Well, maybe here on Earth. But across the Universe, water can be squeezed together at different temperatures and pressures, leading to very different structures. Today we’ll talk about the different forms that ice can take.   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 674: Asteroid Early Warning Systems by Fraser Cain & Dr. Pamela Gay The asteroid apocalypse is one of those existential crises that keep astronomers up at night. But the DART mission showed us that we can push an asteroid off its trajectory if we have enough warning. Today we’ll talk about how humanity is building early warning systems to give us time to respond to a dangerous asteroid.   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 673: How to See Satellites (or Avoid Seeing Them) by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 13, 2023. If you’re in dark skies and look up, you’re certain to see a satellite. Lots of them. But how can you know which one you’re seeing, and how can you improve your chances of a sighting? Today we’ll talk about how to see satellites, or avoid seeing them.   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 672: Space Debris Removal by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 8, 2023. We’ve talked about the rising problem of space junk. Okay, we know it’s an issue. So what can be done about it? Today we’ll talk about ideas to remove space junk, making sure space is open to use for the centuries to come.   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 671: The Consequences to Breaking Space Laws by Fraser Cain & Dr. Pamela Gay Streamed live on Mar 1, 2023. Last week we talked about the laws that govern space exploration. This week the rubber hits the road. What are the consequences for actually breaking these rules? Are they really going to stop anyone?   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 670 - Governing Space: The 1967 Outer Space Treaty & More! by Fraser Cain & Dr. Pamela Ga Streamed live on Feb 13, 2023. The Universe was inaccessible for most of human history, but the first tentative steps to space in the 20th Century made humanity realize that science fiction was becoming science reality. New rules would have to be written to govern how we used this limitless expanse. Today we’ll talk about the Outer Space Treaty of 1967.   This video was made possible by the following Patreon members: David Burry Gowen Jeanette Wink Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela  

Astronomy Cast Ep. 669: Challenges to Dark Energy by Fraser Cain & Dr. Pamela Gay Streamed live on Feb 6, 2023. It’s been over 20 years since astronomers first discovered that the expansion of the Universe is accelerating thanks to dark energy. And in these decades, astronomers still don’t have much evidence for what could be causing the increased expansion rate. Maybe there’s something else going on to explain it.   This video was made possible by the following Patreon members: David Burry Gowen Jeanette Wink Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 668: The Crisis In Cosmology by Fraser Cain & Dr. Pamela Gay Streamed live on Jan 30, 2023. Astronomers have made extremely accurate measurements of the expansion rate of the Universe and come up with different results. And the error bars for the observations don’t overlap, so there’s something strange going on. What’s the answer and how can the Crisis in Cosmology be resolved?   This video was made possible by the following Patreon members: David Burry Gowen Stephen Veit Jordan Young Venkatesh Chary Andrew Poelstra Brian Cagle David Truog THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 667: JWST First Science by Fraser Cain & Dr. Pamela Gay Streamed live on Jan 23, 2023. Astronomers came together in January to present their newest research. And not surprisingly, the winter AAS meeting was heavy on news from the James Webb Space Telescope. What were some of the new results that were announced?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle J.F. Rajotte Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Aurora Lipper David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

  Sign up through to make a difference in the climate crisis, and Wren will plant 10 extra trees in your name!   Streamed live on Jan 17, 2023. Well, we did it. We made it to episode 666, an auspicious number to be sure. What can we do to celebrate this accomplishment? An episode all about things in the Universe that have been named after mythological people and places in the underworld!   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just !) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. Visit us on the web at or email us at .

Astronomy Cast Ep. 665: The Age of Reionization by Fraser Cain & Dr. Pamela Gay The Cosmic Microwave Background Radiation tells us so much about the Universe. After that era, the Universe went dark. Then, as gas pulled together into the first stars and eventually galaxies, light returned, beginning the Age of Reionization.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 664: The First Stars by Fraser Cain & Dr. Pamela Gay This show is sponsored by BetterHelp.  Visit today to get 10% off your first month.   The Sun is a third-generation star, polluted with metals from long-dead suns. Astronomers have also discovered second-generation stars, with very low metallicity. But theories suggest there must be a first generation, with stars made from only pure hydrogen and helium. Can we ever find them?   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 663: End of Year Observing Events by Fraser Cain & Dr. Pamela Gay We generally save our stargazing suggestions for the summer, when it’s warmer in the northern hemisphere. But you’re tough, you can handle a little cold. And it’s worth it because there are some wonderful things you can see in the night sky this time of year.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle J.F. Rajotte Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Aurora Lipper David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 662 - Looking Ahead at New and Recycled Missions by Fraser Cain & Dr. Pamela Gay Last week we talked about the missions we’re saying goodbye to. This week, we’re going to talk about some upcoming missions to say hello to. Some are brand new ideas, others are, uh, recycled.   This video was made possible by the following Patreon members: Burry Gowen Stephen Veit Jordan Young Jeanette Wink Kevin Lyle J.F. Rajotte Venkatesh Chary Andrew Poelstra Brian Cagle David Truog Aurora Lipper David Gerhard Schwarzer THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 660: Runaway! Runaway! Escaping Stars, Planets & Small Bodies by Fraser Cain & Dr. Pamela Gay Moons orbit planets, planets orbit stars, stars orbit within galaxies. It’s orbits all the way down. But occasionally objects can receive a powerful kick that sends them on a journey, never to return.   This video was made possible by the following Patreon members: Burry Gowen Jordan Young Kevin Lyle Jeanette Wink Stephen Veit J.F. Rajotte Andrew Poelstra Venkatesh Chary David Truog TheGiantNothing Aurora Lipper David Gerhard Schwarzer Will Hamilton Brian Cagle   THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 659: Clear Skies, Bright Satellites by Fraser Cain & Dr. Pamela Gay Streamed live on Nov 8, 2022. Light pollution is big problem and it’s only getting worse. Not just near cities, but everywhere thanks to increased satellite constellations. How bad is the problem, and how can we fix it?  

Astronomy Cast Ep. 658: Space Exploration Horror Stories by Fraser Cain & Dr. Pamela Gay Streamed live on Oct 31, 2022. We’re recording this episode on Halloween, so how could we resist but take advantage of this opportunity. Space is already terrifying enough, you know, with the vast endless emptiness, the incomprehensible mysteries, and the uncaring coldness. But here are some scary stories to spook it up a notch.

Astronomy Cast Ep. 657: Astronomical Naming Schemes by Fraser Cain & Dr. Pamela Gay Space is a big place, with lots of galaxies, stars, planets, moons, and that means a lot of names. So how do astronomers name stuff, like comets, asteroids, exoplanets, craters?   This video was made possible by the following Patreon members: Burry Gowen Jordan Young Kevin Lyle Stephen Veit Gerhard Schwarzer J.F. Rajotte Andrew Poelstra Aurora Lipper Brian Cagle David David Truog Jeanette Wink TheGiantNothing Venkatesh Chary Will Hamilton THANK YOU! - Fraser and Dr. Pamela

Astronomy Cast Ep. 656: Smashing Asteroids for Science! by Fraser Cain & Dr. Pamela Gay Streamed live Oct 3rd. This week we saw the incredible image of DART smashing into asteroid Dimorphous. Beyond avenging the dinosaurs, what can we learn scientifically from this and other asteroid/comet impact missions.

Astronomy Cast Ep. 655: 65 Years of Space: Sputnik 1 Anniversary by Fraser Cain & Dr. Pamela Gay Streamed live on Sep 26, 2022. It’s been about 65 years since the Soviets launched the first orbital satellite into low Earth orbit: Sputnik 1. Now there are thousands of satellites in orbit, with tens of thousands on the way. Let’s look at the impact that Sputnik had on the history of spaceflight.

Astronomy Cast Ep. 654: The Side Effects Of Clean Energy by Fraser Cain & Dr. Pamela Gay To battle climate change, we’ll need to rapidly move to carbon-free sources of energy. But this technology isn’t a free lunch. They require metals, generate waste and deplete the environment. What’s the best way to balance this shift?

Astronomy Cast Ep. 653: Climate Change: Looking at the Variables by Fraser Cain & Dr. Pamela Gay Climate change is on our mind these days with increasing wildfires, droughts and floods. What are the variables that play into a planet’s changing climate and what can this teach us about the search for habitable planets in the solar system and across the Milky Way?

Astronomy Cast Ep. 652: The Rocket Race Towards Reusability by Fraser Cain & Dr. Pamela Gay Last week we talked about how single-use rocketry has changed over time, and the role it still plays in launching payloads into orbit and beyond. Today we’ll address the stainless steel elephant in the room and talk about the shift to reusability.

Astronomy Cast Ep. 651: Artemis & The Decline of Single Use Rockets by Fraser Cain & Dr. Pamela Gay Season 16 opener. On the day that we’re recording this, NASA’s Space Launch System is about to blast off. But everyone is expecting it’ll be delayed to October. When it does launch, it’ll be the most powerful rocket on Earth. Well, until Starship blasts off. So are we about to see the end of single-use rockets and enter the era of reusable rocketry?

Astronomy Cast Ep. 650: Did JWST Work? by Fraser Cain & Dr. Pamela Gay Sign up through to make a difference in the climate crisis, and Wren will plant 10 extra trees in your name! Well, this is it. We’re FINALLY going to talk about the James Webb Space Telescope. After decades of development, delays, budget creep, the powerful infrared observatory is at its final home at the L2 Lagrange point. Yesterday (at the time we’re recording this) we saw the first scientific images from the telescope and according to Pamela’s rules, we’re finally allowed to talk about it.

Astronomy Cast Ep. 649: Highlights From NASA’s Holiday Ruining History by Fraser Cain & Dr. Pamela Gay Have you ever noticed that significant space and astronomy events seem to happen during the holidays? It’s not a coincidence. There’s actually a reason why. Today we’ll talk about some of the key events that happened during holidays and the underlying rationale.

Astronomy Cast Ep. 648: Summer Observing by Fraser Cain & Dr. Pamela Gay Summer is officially, astronomically here, and for the folks in the northern hemisphere that means it’s a perfect time to head outside and see what’s happening in the sky. Today we’ll give you a good list of things to keep an eye out for with or without a telescope.

Astronomy Cast Ep. 647: Best Sci Fi Beach Reading by Fraser Cain & Dr. Pamela Gay Summer’s here! And that means finally tackling that huge list of books piled up on your bedside table and filling up your Kindle. What books do we recommend for some fun reads this summer?   - The Kaiju Preservation Society by John Scsalzi - Space Opera by Katherine Valente - The Culture series by Iain M. Banks (The Player of Games) - Six Wakes by Mur Lafferty - Marco and the Red Granny by Mur Lafferty - Reamde and The Fall by Neil Stephenson - Bobiverse series by Dennis E. Taylor - Project Hail Mary by Andy Weir - Childhood’s End by Arthur C. Clark - Lagoon by Nnedi Okorafor - Packing for Mars by Mary Roach - The Mission: A True Story by David Brown - Galaxy: The Prettiest Star by Jadzia Axelrod

Astronomy Cast Ep. 646: Our Long Term Future in Space by Fraser Cain & Dr. Pamela Gay We always say that we're living in golden age of space and astronomy, but it feels like things are just accelerating. Space travel is happening! What does the long-term future hold for our place in the Universe?

Astronomy Cast Ep. 645: The Future of the ISS by Fraser Cain & Dr. Pamela Gay The International Space Station has been continuously inhabited for over 20 years now, serving as a peaceful collaboration between space-faring nations. But it's a machine, and it's getting old. In addition, the Russian invasion of Ukraine has made things, complicated. What's the future for the ISS?

Astronomy Cast Ep. 644: Is Earth… Normal? by Fraser Cain & Dr. Pamela Gay We've now discovered thousands of exoplanets, we're learning more and more about the kinds of planetary systems there are out there across the Universe. But are planets like Earth unique or totally rare?

Astronomy Cast Ep. 643: Sagittarius A* by Fraser Cain & Dr. Pamela Gay All the waiting is over, we've finally seen the image of the event horizon from the supermassive black hole at the heart of the Milky Way. Different shaped blobs! And a black circle in the middle. What are we looking at? Today we're going to explain the picture, and what's next for the Event Horizon Telescope.

Astronomy Cast Ep. 642: Is the Sun... Normal? by Fraser Cain & Dr. Pamela Gay We've always assumed that we lived in a perfectly normal star system with a normal star and normal planets. It's all... normal. But with our modern understanding of billions of stars, just how normal is our Sun, anyway?

Astronomy Cast Ep. 641: Can Planets Be Alive? by Fraser Cain & Dr. Pamela Gay The Earth is teeming with life, but the upper atmosphere to kilometers underground. There's no question that our planet has life. But is our planet itself alive? This is a question posed back in the 1970s as the Gaia hypothesis, and it got its share of criticism. Some new ideas have been proposed to bring this hypothesis to the modern era as we search for exoplanets.

Astronomy Cast Ep. 640: Survey Science: Newest Projects & Results by Fraser Cain & Dr. Pamela Gay There are general-purpose telescopes and missions that astronomers can use to study specific objects. And there are the survey missions that look at the entire sky, which astronomers can use to answer questions about the Universe. We've talked about surveys in the past, but the landscape is changing quickly so it's time for an update.

Astronomy Cast Ep. 639: Big Qs Update: Dark Matter, Dark Energy, Etc. by Fraser Cain & Dr. Pamela Gay Knowledge moves forward, and so, we must move with it. Today we'll give you an update on some of the most fascinating, fast-changing topics in astronomy, astrophysics and cosmology.

Astronomy Cast Ep. 638: Simulating Space Missions by Fraser Cain & Dr. Pamela Gay Although humans have never actually been to Mars, explorers have simulated many aspects of Mars missions here on Earth. There are missions under the ocean, on the tops of volcanoes, in the harsh Canadian north, and even in bed that simulate the limitations of spaceflight, and teach us many of the lessons to prepare us for the real thing

Astronomy Cast Ep. 637: Machine Learning in Astronomy by Fraser Cain & Dr. Pamela Gay Computers are a big part of astronomy, but mostly they've been relegated to doing calculations. But recent developments in machine learning have changed everything, giving computers the ability to do jobs that humans could only do in the past.

Astronomy Cast Ep. 636: Blowing Bubbles by Fraser Cain & Dr. Pamela Gay We think of space as a vacuum, but there are regions of different density. There are winds blowing from stars and other objects that clear out vast bubbles in space, and look absolutely fantastic in pictures. And they might have been critical for Earth to even exist in the first place.

Astronomy Cast Ep. 635: Jets: When Magnetic Fields Fling Things by Fraser Cain & Dr. Pamela Gay As astronomers look out across the Universe. They see various objects spewing jets of material light years into space. What causes these jets? And what impact do they have on the Universe?

Astronomy Cast Ep. 634: Milky Way’s Mergers & Acquisitions by Fraser Cain & Dr. Pamela Gay The Milky Way is a vast grand spiral today, but how did it get this way? Astronomers are starting to unravel the history of our galaxy, revealing the ancient collisions with dwarf galaxies, and how they came together to build the modern Milky Way.

Astronomy Cast Ep. 633: Weirdly Habitable Places by Fraser Cain & Dr. Pamela Gay We've always assumed that habitable planets would need to be like Earth; a terrestrial planet orbiting a sunlike star. But now astronomers have been discovering planets in the habitable zone around very much non-sunlike stars. What strange places could be habitable?

Astronomy Cast Ep. 632: Building Images: Optical vs Radio by Fraser Cain & Dr. Pamela Gay A recent image from the South African MeerKAT Telescope blew our minds. It was a high resolution image of the center of the Milky Way showing delicate filaments and other structures. What was so mind blowing is that this was an image from a radio telescope. Today we’re gonna talk about why this was such an accomplishment and what the future holds for radio astronomy.

Astronomy Cast Ep. 631: All The Uses Of Pulsars (Including Murder) by Fraser Cain & Dr. Pamela Gay Pulsars are the rapidly spinning degenerate husks of dead stars, turning hundreds of times a second. But they're also handy clocks, spinning with such certainty and accuracy that astronomers can use them for all kinds of stuff. We might even use them to navigate the cosmos.

Astronomy Cast Ep. 630: Things We Can Look Forward To by Fraser Cain & Dr. Pamela Gay In a rare moment of weakness, Pamela has decided she's open to the possibility that a future exists. That missions, telescopes and spacecraft are going to be built and they're going to do science. Today we'll talk about what we're looking forward to before she changes her mind and my naive optimism for the future.

Astronomy Cast Ep. 629: The Cost of Delays by Fraser Cain & Dr. Pamela Gay With all the success of James Webb so far, it's looking like science's huge gamble is going to pay off, but there were years of delays and budget overruns. What impacts did these delays have on science, careers, and the future of space exploration?

Astronomy Cast Ep. 628: The Sun Revisited by Fraser Cain & Dr. Pamela Gay Once again, it's time to take a look at the Sun. You know, the ongoing thermonuclear explosion of fusing hydrogen that's right over there. Fortunately, there's a fleet of spacecraft and ground observatories ready to give our best ever view of the Sun, so we can watch it. Always watching…

Astronomy Cast Ep. 627: Mercury Revisited by Fraser Cain & Dr. Pamela Gay It’s been about a thousand years since since we last looked at Mercury. So we figured it’s time for an update. What new things have we learned about Mercury? Or even new questions! Fortunately there’s a mission on the way to help us get some answers.

Astronomy Cast Ep. 626: Terrestrial Planets - Mercury, Venus, Earth & Mars by Fraser Cain & Dr. Pamela Gay We continue our refreshed tour of the solar system, checking in on the inner terrestrial planets, Mercury, Venus, Earth and Mars. What have we learned about the formation, evolution and what they might tell us about planets across the Universe.

Astronomy Cast Ep. 625: End of the Year Review by Fraser Cain & Dr. Pamela Gay We've reached the end of 2021 and this is the last episode of the year. Let's look back at the big space events of the last year and talk about what we're looking forward to in 2022.

Astronomy Cast Ep. 624: Small Rocky Bodies (Including Phobos & Deimos) by Fraser Cain & Dr. Pamela Gay We've talked about the icy objects of the Solar System, today let's talk about space rocks. There's a surprising variety of rocky material in the Solar System, and each object has a story to tell about the history and formation of the planets, moons and other rocky bodies.

Astronomy Cast Ep. 623: NEOs: Concern or Nah by Fraser Cain & Dr. Pamela Gay Are asteroids dangerous? Well, just ask the dinosaurs and they’ll tell you a sad story of fiery death. It turns out we’re in a shooting gallery of space rock and metal. And somewhere out there there’s one with our name on it. Should we be worried? Or are the risks so minimal to be irrelevant.

Astronomy Cast Ep. 622: Rockier Moons & Giant Asteroids by Fraser Cain & Dr. Pamela Gay So a rock is a rock is a rock. Right? Across the solar system there are giant rocky asteroids and even “gianter” rocky moons. What is the difference between these two families of objects and where do they come from?

Astronomy Cast Ep. 621: Gas Giants by Fraser Cain & Dr. Pamela Gay For the longest time the only gas giant planets that we knew about were Jupiter and Saturn. But now, in the age of extrasolar planets, astronomers have discovered thousands of gas giants across almost as many star systems. What new discoveries have been made about gas giants, both here in the solar system and across the Milky Way?

Astronomy Cast Ep. 620: Why Getting to the Outer Worlds is So Difficult by Fraser Cain & Dr. Pamela Gay Good News! Over the next few years we’re gonna see a flotilla of new missions headed to Jupiter and Saturn. Why aren’t we seeing more missions to the outer planets like Uranus and Neptune, even Pluto? It turns out those places are far away. Today let’s talk about the challenges of exploring the outer, outer solar system.

Astronomy Cast Ep. 619: Icy Moons & Dwarf Planets by Fraser Cain & Dr. Pamela Gay The outer Solar System is far enough from the Sun that water doesn't get blasted away into deep space. In this icy realm, there are many worlds with vast quantities of water ice. Today let's look at the icy outer moons and dwarf planets.

Astronomy Cast Ep. 618: Ice Giants by Fraser Cain & Dr. Pamela Gay So we’re learning more & more about the outer planets of the solar system. Uranus & Neptune are Ice Giants, filled with water and other volatiles that we'd consider ice if it was here on Earth. What’s inside these worlds and what can we expect to find across the Milky Way as we find more?

Astronomy Cast Ep. 617: Hangout-A-Thon Episode 2 - Crowdfunding Science by Fraser Cain & Dr. Pamela Gay Funding for basic science has always been tricky business, coming mainly from universities, government, companies or wealthy individuals. But who knows how many fascinating discoveries were never made because of a lack of funding. And we now live in an era where regular people can come together to fund scientific discoveries.

Astronomy Cast Ep. 616: Hangout-A-Thon Episode 1 - The Great Observatories by Fraser Cain & Dr. Pamela Gay Well, you’re familiar with the Hubble Space Telescope of course, but it’s just one of NASA’s Great Observatories. After Hubble came 3 more incredible telescopes. Each greater than the last! (That’s not true… The first one was the greatest.) But together they would fill in almost the entire electromagnetic spectrum.