Broadcast 2941 Hotel Mars with Dr. David Grinspoon

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Guests: John Batchelor, Dr. David Grinspoon, Dr. David Livingston.  Topics:  Planetary defense, Enceladus methanol, Planet 9.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Written Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We do not permit the commercial use of any Space Show program or part thereof, nor do we permit Space Show programs to be edited, placed on YouTube, or other private channels & websites. Space Show programs can be quoted in news articles, papers, academic & research work but must be cited or referenced in the proper citation format. Contact Dr. Livingston for questions about our copyright and trademark policies which we do enforce.  This program is archived on The Space Show website, podcasting, and blog sites with permission from John Batchelor. Please visit the John Batchelor Show website for more information about this fine program,  Remember, your Amazon Purchases Can Help Support The Space Show/OGLF ( note that audio and transition issues are a result of copying the John Batchelor broadcast & are not within my control as they originate in the Batchelor studio.

John Batchelor and I welcomed back Dr. David Grinspoon to discuss planetary defense and the newest NASA mission, DART.  This mission calls for crashing a satellite like item the size of a refrigerator into Didymos B in 2024 to see if it can deflect a small asteroid.  Dr. Grinspoon explained the details of the mission but you can read about it on several websites by searching NASA DART mission or asteroid mission news.  During our discussion, we talked about the gravity tractor idea as well as why it is said we need ten years warning to "save Earth."  John asked why the "experts" frequently use scare language with a close approaching rock.  You do not want to miss these discussions.

We then turned our attention to Enceladus and the discovery of methanol in the atmosphere.  Dr. Grinspoon explained what this meant, why finding organics was important, plus he talked about the relationship of methanol to methane.  Finally, John asked our guest about Planet 9 and I got off one question without an answer before our segment ended. 

You can email Mr. Batchelor or Dr. Grinspoon  through me at or you can do so through Dr. Grinspoon's website,




(Pre-recorded) NEOs and asteroids: How close can they come?

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05 Jul 2017 John Batchelor, Dr. David Grinspoon, Dr. David Livingston
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