The 365 Days of Astronomy

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.

Actual Astronomy - Observer's Calendar For July 07/02/2026

H’ad Astra Historia - Ep 304: More ‘This Month in Astronomical History’ Sedna & Lunokhod 07/01/2026

H’ad Astra Historia - Ep 304: More ‘This Month in Astronomical History’ Sedna & Lunokhod Today’s ‘guest’ is HAD’s This Month in Astronomical History. I’ll be reading more essays from the archives: Emily McMahon’s November 2020 essay titled, “Sedna: In the Depths of the Solar System”, and Dr. Ken Rumstay’s November 2022 essay titled, “Lunokhod 1 - The First Extraterrestrial Rover”. Please note that Emily was a high school student when she wrote her essay, so you don’t have to be an astronomer or astrophysicist to write for TMIAH. H’ad astra historia is the official podcast for the Historical Astronomy Division of the American Astronomical Society. We’re here to share stories from and about the people who study the stars, planets, and the cosmos. We’ll be hearing from individuals who not only study the history of astronomy, but also those who lived it, who were “in the room” during pivotal events within the last 50 years or so. Podcast theme music: "Frost Waltz" Kevin MacLeod (), licensed under creative commons: by attribution 4.0 license () Loretta Cannon (an AAS affiliate via Rose City Astronomers) is a science-and-word-nerd who really likes outer space and the people who study it. She quite enjoys working as HAD’s podcaster, sharing astronomy stories to you. This Month in Astronomical History: Dr. Mugdha Polimera: Sedna: In the Depths of the Solar System TMIAH Nov 2020 “Sedna: In the Depths of the Solar System”: Emily McMahon: Sedna (2003 VB12): Sedna (Inuit legend): Kuiper Belt: Oort Cloud: Palomar Observatory: Mike Brown (CalTech): Chad Trujillo (NAU, Gemini): David Rabinowitz (Yale): Samuel Oschin 48” Schmidt Telescope: Quasar Equatorial Survey Team (QUEST) Camera: SkyMorph program: Palomar Sky Survey: Gemini Telescope: Keck Observatory: Hubble Space Telescope: NASAs’s Dwarf Planets (including Pluto, Eris): Mike Brown’s paper describing Sedna’s discovery: Sedna webpage (by Mike Brown): animation of Sedna’s orbit by Robert Hurt (Spitzer Sci Ctr): 2012 VP113 ‘Biden’: 2015 TG387 ‘The Goblin’: Lunokhod 1 – The First Extraterrestrial Rover TMIAH Nov 2022 “Lunokhod 1 – The First Extraterrestrial Rover”: Prof Kenneth Rumstay: HAD News: Mars Curiosity rover: Soviet Union: Soviet N1 rocket: NASA’s Apollo program: Lunokhod (‘moonwalker’) 1: Baikonur Cosmodrome: Lunar Reconnaissance Orbiter: Sky and Telescope magazine: NPR article on Lunokhod 2 rover (discusses Garriott’s purchase): China’s Yutu rovers: Sputnik I: Artemis Program: A Little Bit of Trivia – NASA mission patches Artemis Program: Artemis I: Marvel’s Agents of S.H.I.E.L.D., season 3: Mission patch: Loretta Cannon’s LinkedIn page (for transcripts’ pdf files): 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 . /episode/index/show/astro365/id/41901495

Cheap Astronomy - Dear CA Ep. 136: Complexities 06/30/2026

Cheap Astronomy - Dear CA Ep. 136: Complexities Things aren’t always straight-forward. Hosted by Steve Nerlich. Dear Cheap Astronomy – What’s all the current fuss about dark energy? Some preliminary data from the Dark Energy Spectroscopic Instrument, also known as DESI has resulted in a swath of popular science articles claiming dark energy is diminishing. Well… It’s worth starting by saying that many of the core project team have stressed it’s just the first data release – there’ll be at least four more, so everyone should probably just chill a bit until more data is available. Dear Cheap Astronomy – Why do eclipse paths run in different directions? Yes folks, it's that rare event when we actually answer an astronomy question. So, solar eclipses. As you know, the Earth's rotation makes the Sun appear to cross the Earth's daytime sky following a line we call the ecliptic. And yep, that's no coincidence, but we'll get to that. The ecliptic is not a fixed path because of the Earth's tilted axis of rotation. So as the Earth progresses in its orbit around the Sun, from the Earth's surface at the equinoxes, the Sun appears to be overhead at the equator, but for the rest of the year it's either shifting north towards the Tropic of Cancer or south towards the Tropic of Capricorn. 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 . /episode/index/show/astro365/id/41789140

Astronomy Cast Ep. 799: Heavy Lift Rockets 06/29/2026

Travelers in the Night Eps. 893 & 894: DarkSky Oregon & Discovery Night at the Schmidt 06/28/2026

The Cosmic Savannah Ep. 083: Celebrating 20 Years of SALT 06/27/2026

EVSN After Hours: Our Shape-Shifting Universe With Author Chanda Prescod-Weinstein 06/26/2026

Space Stories: Habitable Zone: The Search for Another Earth 06/25/2026

Awesome Astronomy - June Part 2: The Secret History of a Space Mission 06/24/2026

Deep Astronomy - Planetary Environments and Health Risks 06/23/2026

Astronomy Cast Ep. 798: Our Summer Media List 06/22/2026

Travelers in the Night Eps. 891 & 892: 2026 AA & 140 Meter Asteroids 06/21/2026

Astroman - C Is For Constellation 06/20/2026

EVSN - Tails SpaceX Fails, Heads We Lose the Earth 06/19/2026

Actual Astronomy - Telescope Powers 06/18/2026

Actual Astronomy - Telescope Powers Hosted by Chris Beckett & Shane Ludtke, two amateur astronomers in Saskatchewan who enjoy teaching astronomy classes and showing the public views through their telescopes. This month we talk about the full range of telescopic magnification powers from Low, Medium to High and how to achieve them using exit pupil. Topics include using exit pupil as a guide to power and how to successfully use high powers. To recap Exit Pupils and Eyepieces: We have High, Medium and Low powers, - Low Power is in the Exit Pupil Range 2-4mm, so on my 180mm f6 that’s 12-24mm eyepieces giving 45x-90x - Medium Power is around 1.5mm Exit pupils, so a 9mm for my scope for 120x - High equates to about a 0.5mm Exit pupil which for an F6 scope that would be a 3mm which on my 180mm would give 360x In addition to these we have RFT or very low power for me I use my 40mm and 32mm for 27-35x and Ultra-high which is anything above 0.5mm. Careful in going to low as beyond 6-7mm exit pupils the pupil will cut into the light path. The most favored eyepiece exit pupils are those in the 1.5-3mm range for galaxies, globular clusters. This is where the eye performs best under low light conditions and these magnifications help reduce the sky brightness without reducing the object brightness to the same extent,,,thus making such objects more visible. This is why I use my 17mm, 12.5, 12, 10mm’s the most when making observations of these targets. For low power wide field nothing beats the 40mm XW which gives me a 2.5TFOV and 27x and I use my 5mm XW lots on the planets and Moon. Shane do you have any high power eyepieces? What is the highest power you’ve successfully used? What are some of the challenges with using high powers? My introduction to using high power came by accident. I wanted to buy all the Pentax XW’s, while designed for spotting scopes, they work perfectly with eyeglasses and each year Pentax would put some on sale. The 20mm is arguable the dog of the lot, the 14mm is a bit better but the rest are of the highest quality so I ended up with these first but soon a after the 3.5mm went on sale and I thought…well…I’d eventually get it anyway so even if I didn’t use it that much it’d be nice to have. Oddly I ended up using it all the time and it is one of my most used eyepieces and not only that but it barlows very well with my 1.6x Nikon creating a 2mm eyepiece. Eventually I acquired the 5mm, 7mm and 10mm and use my 2x and 3x barlows on them. Typically you don’t want to exceed the 0.5mm exit pupil size as on planets floaters and other eye issues challenge the observer. So why would I go above this threshold? So wind the clock back to the Nova East Star party in 2003, Mars was at it’s closest point to earth in 60,000 years and Tony Jones showed up late at night with his 5-inch Astrophysics APO refractor. We ended up barlowing a 4.8mm Nagler 2x for 430x. The details were amazing. Roy Bishop, who has authored that section on Exit Pupils and Eyepieces for the OH was there, he explained that while no additional detail could be seen past about 300x making the image this large made the details that could be seen larger. I’ve always enjoyed running high power on Mars and the 3.5mm on my 60mm Tak gives splendid views of Venus in the 100x range. With the 180mm f6 my 3.5mm gives 308x and on steady nights I have used up to 500x. After experimenting I determined the optimal magnification limit is about 430x and that coincides with the actual theoretical limits discussed in many texts and online posts. I found that the Pentax 70-degree AFOV was a bit restrictive and wanted to use my 84-degree Docter. I ran across the SkyWatcher Nomad 5x Telecentric Barlow, Telecentrics don’t move the exit pupil around and I have found sometimes SkyWatcher has a few hidden gems…it was only about $100EU and not available in NA so I thought I’d give it shot. It works perfectly, I get 432x and the field of view is excellent! 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 . /episode/index/show/astro365/id/41686510

Cheap Astronomy - Dear CA Ep. 135: Going Nuts 06/17/2026

Ask A Spaceman Ep. 274: Is Dust the Best Thing in the Universe? 06/16/2026

Ask A Spaceman Ep. 274: Is Dust the Best Thing in the Universe? All Hail Dust! Hosted by Dr. Paul M. Sutter. Why is dust so annoying? But where does it come from, and what can it do? And is dust responsible for the creation of life? I discuss these questions and more in today’s Ask a Spaceman! Support the show: All episodes: Watch on YouTube: Read a book: Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE! Big thanks to my top Patreon supporters this month: Justin G, Chris L, Alberto M, Duncan M, Corey D, Michael P, Naila, Sam R, Joshua, Scott M, Rob H, Scott M, Louis M, John W, Alexis, Gilbert M, Rob W, Jessica M, Jules R, Jim L, David S, Scott R, Heather, Mike S, Pete H, Steve S, Lisa R, Kevin B, Aileen G, Deb A, Michael J, Phillip L, Steven B, Mark R, Alan B, Craig B, Richard K, Joe R, David P, Justin, Robert B, Tracy F, Ella F, Thomas K, James C, Syamkumar M, Homer V, Mark D, Bruce A, Tim Z, Linda C, The Tired Jedi, Bob C, Stephen A, James R, Allen E, Michael S, Sheryl, David W, Chris, Michael S, Erlend A, James D, Karl W, Den K, Edward K, Scott K, Vivek D, M0PPET, Barbara C, Brad, Azra K, Steve R, Koen G, Scott N, M D Malahy, Brian O, and Alonna M! 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 . /episode/index/show/astro365/id/41657670

Astronomy Cast Ep. 797: Summer in Space 06/15/2026

Travelers in the Night Eps. 889 & 890: Lick Observatory & Comet 467P (Linear-Grauer) 06/14/2026

Travelers in the Night Eps. 889 & 890: Lick Observatory & Comet 467P (Linear-Grauer) Dr. Al Grauer hosts. Dr. Albert D. Grauer ( ) is an observational asteroid hunting astronomer. Dr. Grauer retired from the University of Arkansas at Little Rock in 2006. From March 2026. Today's 2 topics: - In 1892 the world’s largest telescope, the Lick Observatory’s 36 inch refracting telescope made the news when E.E. Barnard discovered, Amalthea, the 5th moon of Jupiter. In 2025 this historic telescope made the news again when on Christmas morning winds of 114 mph blew off a 3 ton piece of the shutter on its dome. The adaptive optics research pioneered at Lick Observatory helped in the creation of the twin giant 10 meter telescopes that sit atop Mauna Kea in Hawaii. - Astronomers using the 8.1 m Gemini South Telescope in Chile were excited by the fact that 467P (LINEAR-Grauer)’s Centaur like orbit had been changed as the nucleus emitted rocket like bursts of gases as it was warmed by the Sun. Inert inactive asteroids orbit the Sun following the law of gravity whereas active asteroids can emit little rocket like bursts of gas which can change their path about the Sun in interesting ways. It is important to study objects like 467P (LINEAR-Grauer) to make sure their path about the Sun doesn’t change to make them a threat to our home planet. 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 . /episode/index/show/astro365/id/41605830

NOIRLab - Strong Hints of Magnetic Fields On Exoplanets 06/13/2026

EVSN - Chasing Chemistry: Missions Measure Comet & Planet Atmospheres 06/12/2026

Actual Astronomy - Observer’s Calendar for June 06/11/2026

Awesome Astronomy - Psyche, Poet and Astronomy Exams 06/10/2026

Deep Astronomy - Vega: The Second Most Important Star in Our Sky 06/09/2026

Astronomy Cast Ep. 796: Oceans & Organics on Mars 06/08/2026

Travelers in the Night Eps. 887 & 888: Apophis Bound & Investigating the Mystery of How Life Formed 06/07/2026

Travelers in the Night Eps. 887 & 888: Apophis Bound & Investigating the Mystery of How Life Formed Dr. Al Grauer hosts. Dr. Albert D. Grauer ( ) is an observational asteroid hunting astronomer. Dr. Grauer retired from the University of Arkansas at Little Rock in 2006. From February 2026. Today's 2 topics: - In April 2029 on one of the luckiest Friday the 13th in human history the 1,500 ft by 500 ft asteroid Apophis will pass within 23,600 miles of the Earth’s surface traveling at some 4.6 mi/s. This is extremely fortunate since an Apophis impact would release the energy of scores of nuclear weapons and cause wide spread devastation. NASA's OSIRIS-APEX will become the companion of the potentially hazardous asteroid Apophis on 5 June 2029. - On Earth living things are everywhere from the deepest ocean depths to the highest mountain tops. On our home planet RNA (Ribonucleic Acid) is a complex essential molecule involved in the process of translating genetic information into the working components of living cells. In a recent paper in the peer reviewed scientific journal Proceedings of the National Academy of Sciences, Dr. Yuta Hirakawa and his team of two coauthors report on their experiments to produce RNA under conditions similar to those which may have occurred in the early history of Earth and Mars. 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 . /episode/index/show/astro365/id/41552755

Equatorial Sky Guide - June Episode 06/06/2026

EVSN - After Hours: Crowdsourcing Innovation with Trisha Epp 06/05/2026

Guide To Space - Lunar Rovers, From Apollo to Artemis 06/04/2026

Awesome Astronomy - June Part 1: Objects In the Golden Mirror May Be Closer 06/03/2026

The 365 Days of Astronomy

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