Universe Today Podcast

Latest Episodes:

Episode 586: Q&A 105: Why Not Send Earth Life to Europa? And More... Featuring Back to Space Nov 08, 2019

Show notes

In this week's questions show, I tackle questions about seeding Europa with hardy Earth life, what makes galaxies spin, what are we competing with aliens for, and why is it so hard for second stages of rockets to land?

Subscribe to Back to Space
https://www.youtube.com/channel/UCHZ63YtVtdQDqLxKyTDmtmw

01:46 Why not take Earth life to Europa?
04:00 What if the aliens are aligned to Planet 9?
06:09 What makes a galaxy spin?
07:22 What are we competing with aliens for?
09:39 Are we constantly reusing atmosphere on ISS?
11:33 Should we settle ice worlds?
13:52 Why can't second stages be landed?
17:03 Does Sag A* spin the same way as the Milky Way?
20:22 Is the search for life in space a waste of time?
21:59 Could asteroid mining change their orbits?
23:51 Would SpaceX send NASA astronauts to Mars?
24:25 How much fuel does ISS need?
25:01 What kind of training do astronauts get?
25:52 What is Max Q?

Want to be part of the questions show? Ask a short question on any video on my channel. I gather a bunch up each week, and answer them here.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Support us at: https://www.patreon.com/universetoday
More stories at: https://www.universetoday.com/
Twitch: https://twitch.tv/fcain
Follow us on Twitter: @universetoday
Like us on Facebook: https://www.facebook.com/universetoday
Instagram - https://instagram.com/universetoday

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

Support Universe Today Podcast

Episode 585: Can Life Spread From Star to Star? The Theory of Galactic Panspermia Nov 05, 2019

Show notes

The race is on to find life in other places in the Solar System, from underground reservoirs on Mars to the subsurface oceans on Europa and Enceladus.

If spacecraft, rovers or even astronauts make the momentous discovery of life on another world, that’ll just open up new questions. Did it originate all on its own, completely independently from Earth, or are we somehow related? And if we are related, how long ago did our evolutionary trees branch away from each other.

Even though Mars is millions of kilometers away, it could be possible that we’re still related thanks to the concept of Panspermia; the idea that meteor impacts could transfer rocks and maybe even living creatures from world to world.

But could you go one step further? If we find life on another star system, could we discover that we’re actually related to them too? Is Galactic Panspermia possible?

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Support us at https://www.patreon.com/universetoday
More stories at https://www.universetoday.com/
Twitch: https://twitch.tv/fcain
Follow us on Twitter: @universetoday
Like us on Facebook: https://www.facebook.com/universetoday
Instagram - https://instagram.com/universetoday

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

References:
https://www.hoyle.org.uk/resources/virusesfromspacecompressed.pdf
https://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.shtml
https://www.planetary.org/blogs/emily-lakdawalla/2013/03211549-lpsc-hermean-meteorite.html
https://www.dlr.de/me/en/desktopdefault.aspx/tabid-1752/2384_read-54290/
https://memory-alpha.fandom.com/wiki/Humanoid
https://phys.org/news/2018-08-timescale-evolution-life-earth.html
https://arxiv.org/ftp/arxiv/papers/1011/1011.0101.pdf
https://www.planetary.org/blogs/guest-blogs/2013/20130926-gravity-assist.html
https://arxiv.org/abs/1011.0101
https://phys.org/news/2010-11-necropanspermia-seeding-life-earth.html
https://academic.oup.com/mnras/article/198/3/723/1012846
https://arxiv.org/pdf/1910.06414.pdf
https://www.nasa.gov/feature/goddard/2019/hubble-observes-1st-confirmed-interstellar-comet/
https://academic.oup.com/mnras/article/476/3/3031/4909830
https://nssdc.gsfc.nasa.gov/planetary/hyakutake.html
https://www.youtube.com/watch?v=q2YkvWdUUNQ

Support Universe Today Podcast

Episode 584: Surviving On Venus. Is It Time To Go Back To That Awful Place? Oct 30, 2019

Show notes

If you’ve watched this channel enough, you might have the impression that I hate Venus. It’s possible, just possible I’ve even suggested that the planet is so terrible it should be pushed into the Sun.

The reality, of course, is that it’s an absolutely fascinating world - the closest twin to the Earth that we have in the Solar System. It’s nearly the same mass and has the same surface gravity.

While Earth is the beautiful life-filled world we all enjoy, Venus is a tortured hellscape, with temperatures hot enough to melt zinc. With atmospheric pressures more than 93 times what we experience here on the surface of Earth. And I always forget about the sulphuric acid rain.

The Soviets sent a series of landers to a horrible demise for a glimpse of the surface of Venus in the 70s and 80s. But nobody’s been back since.

There have been new techniques and technologies in development that might make a serious exploration of the surface of Venus possible again. Exploration that could help us understand why the planet went so horribly horribly wrong.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

References:
https://www.lpi.usra.edu/vexag/vexag_goals_2007.pdf
https://www.nasa.gov/feature/jpl/nasa-studying-shared-venus-science-objectives-with-russian-space-research-institute
https://www.nytimes.com/1984/12/16/world/soviet-spacecraft-heads-for-comet.html
https://www.planetary.org/blogs/guest-blogs/2015/0305-venus-from-33-years-ago.html
https://www.researchgate.net/publication/268472597_Analysis_of_Solar_Cell_Efficiency_for_Venus_Atmosphere_and_Surface_Missions
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2017EA000355
https://www.hou.usra.edu/meetings/lpsc2018/pdf/1243.pdf
http://www.russianspaceweb.com/venera_d.html
https://www.lpi.usra.edu/vexag/meetings/archive/vexag_14/presentations/27-Kremic-Long-Lived%20Venus%20Station.pdf
https://science.nasa.gov/technology/technology-stories/electronics-demonstrate-operability-in-simulated-venus-conditions
https://www.nasa.gov/feature/jpl/a-clockwork-rover-for-venus
https://www.lpi.usra.edu/vexag/meetings/archive/vexag_15/presentations/9-Saunder-AREE.pdf
https://www.youtube.com/watch?v=u9fki7dligU
https://www.nasa.gov/directorates/spacetech/niac/2012_phase_I_fellows_landis.html
https://www.newscientist.com/article/dn12905-antique-fridge-could-keep-venus-rover-cool/

Support Universe Today Podcast

Episode 583: A Single Spacecraft Will Visit Seven Asteroids. NASA's Lucy Mission Passes Its Design Review Oct 30, 2019

Show notes

Scientists have had the opportunity to examine several asteroids in the Solar System now, and what they’ve learned is how much variety is out there, depending on the mass, distance from the Sun and composition.

Astronomers currently know of 829,400 asteroids across the Solar System, and they’d love to visit as many of them as possible to learn more about them.

Considering the price of a single spacecraft, that’s going to get expensive. Fortunately, there are places in the Solar System that have trapped a large number of asteroids in a way that a single spacecraft can visit several of them as part of a mission.

They’re at Jupiter’s L4 and L5 Lagrange points, and this week NASA approved a new mission that’ll explore 7 different asteroids over a 12-year journey.

It’s called Lucy.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

References:
https://www.nasa.gov/feature/goddard/2019/lucy-mission-clears-critical-milestone
https://www.lpi.usra.edu/decadal/sbag/topical_wp/AndrewSRivkin-trojans.pdf
https://www.nasa.gov/content/goddard/lucy-the-first-mission-to-jupiter-s-trojans
http://lucy.swri.edu//mission/Targets.html
https://www.esa.int/Science_Exploration/Space_Science/Asteroids_Structure_and_composition_of_asteroids
https://sci.esa.int/web/mars-express/-/31031-phobos
http://lucy.swri.edu//mission/Spacecraft.html

Support Universe Today Podcast

Episode 582: Q&A 104: Should We Reconsider The Definition Of A Moon? And More... Oct 30, 2019

Show notes

In this week's questions show, I explain why it's probably not time to reconsider the definition of a moon, if we could make artificial gravity with a chunk of a neutron star, and why a supermassive black hole isn't the anchor for an entire galaxy.

00:47 Should we reconsider the definition of a moon?
03:35 Could we make artificial gravity with mass?
05:48 Why didn't the Big Bang collapse back into black hole?
07:47 Why can't a black hole be the anchor of the galaxy?
10:45 How far and how small can we see?
13:37 What is left after a black hole evaporates?
15:00 Could you have a star made out of something else?
16:32 Could a planet orbit a binary star?
18:29 Could aliens Planet 9?
19:24 If aliens are advanced, we're no threat
21:35 How can aliens not exist?
22:30 Why don't they put a microscope in a rover?

Want to be part of the questions show? Ask a short question on any video on my channel. I gather a bunch up each week, and answer them here.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

Support Universe Today Podcast

Episode 581: Open Space 50: When Will There Be Giant Rotating Space Stations? And More... Oct 28, 2019

Show notes

In this week's live QA, we talked about rotating space stations, the materials that can be made in space, what telescopes and binoculars I use. And there were a lot of questions about James Webb.

04:15 When will we see a rotating space station?
09:27 Are there materials that can only be made in space?
11:11 What's my telescope?
12:51 What are my binoculars?
13:47 What's the status of the B612 Foundation?
15:16 Could we terraform Venus?
17:52 More on my binoculars
19:19 Should we build a sunshield to offset climate change?
21:43 If SLS is canceled, what happens?
26:42 What happens when there's no mass?
28:45 What are my hopes about James Webb?
31:47 Is there a finite amount of mass in the Universe?
32:07 Is there a backup James Webb?
33:45 How is time affected in zero mass?
34:15 Why launch James Webb from South America?
36:44 Borisov is coming through the ecliptic
37:37 Will LUVOIR get built?
40:35 Will James Webb find Planet X?
41:15 Is the Planetary Society a lobbiest organization?
44:20 Will we migrate to another planet?
49:36 Sea Dragon revisted?
50:47 Where would I go in the Universe?
55:46 Could we use asteroids for tourism?
58:15 What if Starship landed on Titan?

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

Support Universe Today Podcast

Episode 580: Is Humanity Prepared To Discover Alien Life? Oct 25, 2019

Show notes

People always ask me how I think humanity will react if we discover life somewhere out there in the Universe, whether it’s bacteria under the surface of Mars, a biosignature of alien life in the atmosphere of another world, or a radio signal from another civilization.

Will our civilization lose its collective mind and have a temper tantrum on a global scale? Will we become one of those purge planets from Rick and Morty?

Will the discovery suddenly end all religion, as we wait for guidance from our new alien overlords?

Will we gather together as a species to present a common front to whatever cosmic horrors await us beyond the Solar System?

In my opinion, if I could sum up the collective response in a single word, it would be: meh.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

References:
https://www.cnn.com/2019/09/30/us/nasa-life-on-mars-jim-green-scn-trnd/index.html
http://www.gutenberg.org/ebooks/47015
https://archive.org/details/marsabodeoflife00loweiala/page/n8
https://blogs.scientificamerican.com/observations/im-convinced-we-found-evidence-of-life-on-mars-in-the-1970s/
https://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.shtml
https://www.astrobio.net/mars/the-continuing-controversy-of-the-mars-meteorite/

Support Universe Today Podcast

Episode 579: Q&A 103: How Many Stars Have Zero Planets? And More... Oct 18, 2019

Show notes

In this week's questions show, I explain why we'll never know which stars have no planets. How we could prevent a catastrophe to Earth, and why aliens might still be a threat to us.

Check out more of Dustin Gibson's photographs at:
https://www.instagram.com/gibsonpics/

00:48 How many stars don't have planets?
02:29 Could we prevent a catastrophe?
05:16 No aliens would be a threat to us
07:38 Can I have any name for Patreon?
08:20 Why not put a laser on the solar sail spacecraft
09:40 How can neutrinos go faster than light?
10:45 How do you calculate exposure times for Hubble?
14:32 What would cause stars to collide
17:19 Why don't we track asteroids?
18:55 How do magnetars form?
20:36 How could we destroy the planet?
22:45 Can a brown dwarf become a star?

Want to be part of the questions show? Ask a short question on any video on my channel. I gather a bunch up each week, and answer them here.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

Support Universe Today Podcast

Episode 578: Open Space 49: How Can Planets Capture Asteroids? And More... Oct 15, 2019

Show notes

No guest this week, just a live QA with me and the audience about all things space and astronomy. People had questions about how planets can capture asteroids to turn them into moons, what rocket James Webb will use to fly to space, and why you can't use antimatter to destroy a black hole.

05:45 How can a planet capture an asteroid?
07:21 Why are quasars so far from us?
09:26 How could you make a black hole of photons?
11:25 Would I rather live a year on the Moon or Mars?
12:46 What will JWST launch on
14:08 What's the limit on a planet's mass for rocketry?
17:06 Do I prefer to observe alone?
18:55 Why doesn't antimatter destroy black holes?
20:43 Will we get space engines from The Expanse?
24:05 Shouldn't we solve our problems here on Earth?
26:30 What happens to us when the Sun dies?
28:28 Why aren't there video cameras on Mars?
30:00 How do we learn about what things are made of with radio waves?
32:00 Are there any metals in space that can't find on Earth?
33:12 How do we measure distances to stars?
35:16 EMDrive
36:23 Are metals precious to the planet you're on
37:05 Will Skylon fly?
38:35 Cyanogen gas in comets
39:12 Talking to people who don't care about space
41:00 How do planets start forming?
41:48 What do I think of antimatter rockets?
43:09 Could we build an arm to lift us to space?
43:32 Should we just colonize space itself?
44:20 Is Planet 9 a black hole?
50:11 Does Canada have radio telescopes?
50:50 When will a black hole turn into regular matter again?
51:30 Wildlife on Vancouver Island
53:13 Could breakthrough starshot work to redirect asteroids?
54:25 Could we see life on Alpha Centauri?
57:00 Is Alpha Centauri visible from the North?
57:30 Would generation ships work?

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

Support Universe Today Podcast

Episode 577: AstroClipper: Plans For A Two-Stage, Fully Reusable Spaceplane Oct 15, 2019

Show notes

Even as the first rockets were launched into space decades ago, aerospace knew it was a wasteful process. Rocket stages, motors, and complex equipment crashed into the ocean or burned up in the Earth’s atmosphere.

Could spaceplanes bring the costs down? Flying to orbit with a combination of jet engines and rockets and then safely re-enter the Earth’s atmosphere again.

Single-stage to orbit spacecraft and spaceplanes have always seemed out of reach, and actually not that practical. But what about a two-stage, fully reusable spaceplane?

Exodus Space Corporation has been secretly working on this concept for a decade now, and what they’re proposing is pretty revolutionary.

Our Book is out!
https://www.amazon.com/Universe-Today-Ultimate-Viewing-Cosmos/dp/1624145442/

Audio Podcast version:
ITunes: https://itunes.apple.com/us/podcast/universe-today-guide-to-space-audio/id794058155?mt=2
RSS: https://www.universetoday.com/audio

What Fraser's Watching Playlist:
https://www.youtube.com/playlist?list=PLbJ42wpShvmkjd428BcHcCEVWOjv7cJ1G

Weekly email newsletter:
https://www.universetoday.com/newsletter

Weekly Space Hangout:
https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/

Astronomy Cast:
https://www.youtube.com/channel/UCUHI67dh9jEO2rvK--MdCSg

Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / https://www.youtube.com/channel/UCEItkORQYd4Wf0TpgYI_1fw
Chad Weber - weber.chad@gmail.com

References:
https://history.nasa.gov/SP-4407/vol4/cover.pdf
https://io9.gizmodo.com/early-design-specs-show-the-space-shuttle-could-have-be-1528524224
https://www.exodus-space.com/
https://www.exodus-space.com/astroclipper/
http://fiso.spiritastro.net/telecon/Ayala_10-9-19/Ayala_10-9-19.pdf

Support Universe Today Podcast