Podcaster: Beth Johnson, Franck Marchis, and Simon Steel (alternate hosts); Guest: Colby Ostberg

Title: SETI Live: Hot Spot on the Moon – Granite Batholith Found Below Surface

Organization: SETI Institute

Link: ; Preprint of the paper:


The Apollo missions showed scientists that the craters on the Moon were from impacts rather than volcanoes, overturning previously held hypotheses. Now, new research using data collected by China’s Chinese Chang’E 1 and 2 orbiters has discovered a hot spot under the surface. Using an instrument that made observations at microwave wavelengths, the team mapped out temperatures and found one particular suspected volcano, known as Compton-Belkovich, glowed in the microwave. 

However, surface evidence shows the volcano last erupted about 3.5 billion years ago, and the heat is coming from radioactive elements in the solid rock. That radioactivity led scientists to conclude that under the surface lies a large chunk of granite – magma that cooled underground – providing evidence for the most Earth-like volcanism found on the Moon to date.

Join planetary astronomer Dr. Franck Marchis as he discusses these interesting new findings with lead author Dr. Matt Siegler, Senior Scientist at the Planetary Science Institute. 

Bio: Beth Johnson is a communications specialist and social media manager with a degree in physics and master’s work in planetary science. She specializes in meteor showers, icy moons, and anything with volcanoes.

Franck Marchis is a senior planetary astronomer and chair of the exoplanet group at the Carl Sagan Center of the SETI Institute and Chief Scientific Officer and Founder at Unistellar. He has dedicated his work to the study of our solar system, specifically the search for asteroids with moons, using mainly ground-based telescopes equipped with adaptive optics.

Simon Steel is Deputy Director of the Carl Sagan Center for Research at the SETI Institute. As an observational astrophysicist, he specialized in optical spectrophotometry, with an interest in the star formation histories of galaxies.

Dr. Matt Siegler, Senior Scientist at the Planetary Science Institute. 

Today’s sponsor:  Big thanks to our Patreon supporters this month:  Paul M. Sutter, Chris Nealen, Frank Frankovic, Frank Tippin, Jako Danar, Michael Freedman, Nik Whitehead, Rani Bush, Ron Diehl, Steven Emert, Brett Duane, Don Swartwout, Vladimir Bogdanov, Steven Kluth, Steve Nerlich, Phyllis Foster, Michael W, James K Wood, Katrina Ince, Cherry Wood.

Please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at

Please visit our Patreon page:

or you can consider to sponsor a day of our podcast :

365 Days of Astronomy

The 365 Days of Astronomy Podcast is produced by Planetary Science Institute. Audio post-production by Richard Drumm. Bandwidth donated by and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. 

This show is made possible thanks to the generous donations of people like you! Please consider supporting to our show on and get access to bonus content. 

After 10 years, the 365 Days of Astronomy podcast is entering its second decade of sharing important milestone in space exploration and astronomy discoveries. Join us and share your story. Until tomorrow! Goodbye!