

The 365 Days of Astronomy
365DaysOfAstronomy.org
The 365 Days of Astronomy podcast launched in 2009 as part of the International Year of Astronomy. This community podcast continues to bring you day after day of content across the years. Everyday, a new voice, helping you see the universe we share in a new way. This show is managed by Avivah Yamani, edited by Richard Drumm. This podcast is funded through Patreon.com/CosmoQuestX and produced out of the Planetary Science Institute.
Episodes
Mentioned books

Feb 2, 2026 • 34min
Astronomy Cast Ep. 780: When Asteroids & Comets Attack!
https://www.youtube.com/watch?v=sIVunut4Dgk Hosted by: Fraser Cain (@frasercain ) and Dr. Pamela L. Gay (@CosmoQuest ) Streamed live on Jan 26, 2026. We live in a cosmic shooting gallery. It's not a matter of "if" but "when"! Dinosaurs, blah, blah, blah. You know the drill. But seriously, folks, it's raining rocks & ice out there! How seriously should we take it? What happens when a variety of different objects hit the Earth? Different kinds of objects affect Earth very differently when they impact. Let's discuss what makes an impactor more or less dangerous. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Burry Gowen, Eric Lee, Jeanette Wink, Michael Purcell, Andrew Poelstra, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Joe McTee, Sergey Manouilov, Siggi Kemmler, Sergio Sancevero We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Feb 1, 2026 • 6min
Travelers in the Night Eps. 851 & 852: Scientists Views Odds of Aliens & Landing On Mars
Dr. Al Grauer hosts. Dr. Albert D. Grauer ( @Nmcanopus ) is an observational asteroid hunting astronomer. Dr. Grauer retired from the University of Arkansas at Little Rock in 2006. travelersinthenight.org From May & June, 2025. Today's 2 topics: - In a recent paper published in Nature Astronomy entitled "Surveys of the scientific community on the existence of extraterrestrial life" Dr. Peter Vickers and his team of 10 co-authors report the results of their survey of the lead authors for the past 10 years in the top three astro-biological journals. These researchers sought to measure if their sample group of scientists thought it likely that: 1) simple life, and/or 2) life more complex than terrestrial bacteria, and/or 3) Intelligent life comparable or superior to human beings exists outside of Earth. For more: https://cosmoquest.org/x/365daysofastronomy/2014/07/24/july-24th-are-we-alone/ - The good news is a Mars landing by human colonists and their equipment seems technically feasible given a large budget of cash and grit. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 31, 2026 • 8min
Space Stories - Perihelion & Aphelion
Hosted by our Director, Avivah Yamani. Earth swings closest to the Sun at perihelion and farthest at aphelion, words that apply to every planet orbiting the Sun. Learn how Kepler's laws reveal an elliptical orbit, why Earth moves faster at perihelion, and why seasons come from Earth's tilt, not distance. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 30, 2026 • 21min
EVSN - Mystery of Mars' Recurring Slope Lineae Possibly Solved
From February 8, 2021. A new theory has been proposed that could answer the question of what causes recurring landslides on Mars: small-scale ice melting just below the surface may leave the regolith vulnerable to wind. Plus, a look at some of Earth's ancient climate changes, a gamma-ray source, puffy galaxies, and this week's What's Up. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 29, 2026 • 11min
Guide to Space - Thanks To Gaia We Now Know Exactly Where 1.7 Billion Stars Are In The Milky Way
https://www.youtube.com/watch?v=lxgdcG_NQyA Hosted by Fraser Cain. And a happy robin. From May 3, 2018. The European Space Agency just dropped an enormous amount of data onto the scientific community. The location and position of 1.7 billion stars in the Milky Way. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 28, 2026 • 57min
Awesome Astronomy - 3 Days to Lose LEO
Paul Hill and Dr. Jenifer "Dr. Dust" Millard host. Damien Phillips, John Wildridge and Dustin Ruoff produce. So it looks like Low Earth Orbit is not just crowded but a disaster waiting to happen trapping humanity on this planet for a very long time… https://www.esa.int/Space_Safety/Space_Debris/Space_debris_by_the_numbers https://arxiv.org/abs/2512.09643 We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 27, 2026 • 15min
Cheap Astronomy - Dear CA #128: Persistent Claims
Still looking. Hosted by Steve Nerlich. Dear Cheap Astronomy – Is there anything new on Planet 9? Well, not really and there is some growing skepticism about whether it's really there. Nonetheless, its original proponents, Mike Brown and Konstantin Batygin, still stick to their guns on the matter, though both agree Planet 9's existence must be considered speculative until it is actually observed. Dear Cheap Astronomy – Is Nemesis really out there? Continuing the theme of hypothetical solar system bodies, Nemesis was proposed to be a small, dim and hence difficult to spot companion star of the Sun. Its existence was proposed in 1984 on the basis of a perceived 27 million year cycle in mass extinction events, where anything cyclical gets people thinking about orbits – and with a 27-million-year periodicity, you need a pretty big orbit. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 26, 2026 • 36min
Astronomy Cast - Questions: Relativity, Relativity & More Relativity
From October 23, 2008. Hosted by Fraser Cain & Dr. Pamela Gay. Everyone loves a theme. And this week we've collected together some of your questions about relativity. More light speed spacecraft, twin paradoxes, and the mixing up of gravity, time and mass. If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name. - What would happen if you're traveling close to light speed through the solar system — would you mess it up? - If I watched my friend accelerate close to speed of light, will I see him get younger or age slower? - Can parts of the Universe be traveling back in time? - What form does relativistic mass increase take? - Why don't photons have mass? - Twin paradox: Why is the "stay at home" twin's frame of reference preferred? - Does gravity equal time? - How can the state of an electromagnetic wave change when the wave exists outside of time? - How do we know the speed of light constant? Could it be different in different part of the universe? We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 25, 2026 • 6min
Travelers in the Night Eps. 849 & 850: Europa Clipper & Who Owns A Space Rock?
Dr. Al Grauer hosts. Dr. Albert D. Grauer ( @Nmcanopus ) is an observational asteroid hunting astronomer. Dr. Grauer retired from the University of Arkansas at Little Rock in 2006. travelersinthenight.org From May, 2025. Today's 2 topics: - NASA's Europa Clipper was launched October 14, 2024 on a mission to conduct a detailed study of Jupiter's Moon Europa. The space craft will travel some 1.8 billion miles and should reach Jupiter in April 2030. This mission will begin to tell us if life as we know it can occur relatively close to home. - Since there is a world wide market for meteorites some of which can be sold on line, for millions of dollars, the question of ownership becomes important. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.

Jan 24, 2026 • 1h 2min
Cosmic Savannah Ep 78: Back Under the Stars - A New Dawn
Hosted by Dr. Jacinta Delhaize, Dr. Tshiamiso Makwela, Dr. Daniel Cunnama & François Campher. At long last…we're back!!! The Cosmic Savannah is entering an exciting new era as we transition into a video podcast! In this episode, we kick off that journey and invite you to join us as we venture even deeper into the cosmic ocean—exploring the universe, sharing new perspectives, and connecting with the people who bring astronomy to life. Exciting times lie ahead, and we're thrilled to have you along for the ride. In this episode, the team also reflects on the past 12 months, and in particular on the International Astronomical Union's General Assembly – a massive astronomy conference that was held in Cape Town one year ago. The Cosmic Savannah intern Kaashifa Saloojee makes her microphone debut as she speaks with special guest Kevin Govender. Kevin was the Chair of the IAU GA National Organising Committee and is the Director of the Office of Astronomy for Development (OAD), based in Cape Town. With a background in Nuclear Physics, Kevin first became involved in astronomy in 2006 when he managed the Collateral Benefits Programme at the South African Astronomical Observatory (SAAO). This work ultimately led to his appointment as the inaugural Director of the OAD in 2011. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy 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 http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.


