Broadcast 2917 Michael Summers

19 May 2017 Michael Summers
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Guest:  Dr. Michael Summers;  Topics:  In depth exoplanet discussion based on the book written by our guest, "Exoplanets."  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website, www.thespaceshow.com.   Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm.   

We welcomed Dr. Michael Summers to the program to discuss his new book, "Exoplanets."  Co-authored with Dr. James Trefil, this books provides us with new information which enables us to broadly and widely expand our view and understanding of exoplanets and the searches underway to find and identify them.  During the first segment of our nearly 92 minute program, Dr. Summers responded to a question I asked him about what we might expect to find were we able to do a full sky survey for exoplanets rather than the narrow search afforded us by the Kepler Space Telescope (KST).  Dr. Summers said we would soon be expanding our exoplanet search with the launch in 2018 of the Transiting Exoplanet Survey Satellite (TESS) that will be able to do wide area scans for exoplanets.  In addition, the JWST will soon be coming on line plus new and larger ground based telescopes are coming on line and planned for the near future.  Our guest said that currently there were about 3,600 exoplanets found but the number changes daily as we are always finding more.  He said that number will increase substantially with the new resources coming on line soon (those he mentioned and more).  I asked him if all these new resources looking for exoplanets and hoping to find one with life means that we are shortening the timeline for finding some type of extraterrestrial life.  Don't miss his response to this question.

This question led us to a discussion of life and the bias that we have in our search given we look for life as we know it and that we can detect.  He said newer approaches and searches were looking for biomarkers in the atmosphere of exoplanets, signs that some form of life might be going on, even if unfamiliar to us.  He said some of the biomarkers include methane and water but they also look for carbon monoxide, CO2, sodium vapor, O2, and other gasses.  The science of looking for biomarkers in the exoplanet atmosphere is young so we should expect to see more in this area in the near future.

Since our guest had mentioned rogue planets in his earlier comments, I asked him what a rogue planet was.  He said they were also referred to as dark or stealth planets.  A rogue planet does not have a gravitational bound to a star.  Such a planet floats around between stars.  We had a very interesting discussion about rogue planets, what it might mean for spaceflight and more.  Make sure you hear the full discussion on this subject.  It was most interesting. 

As a result of our rogue planet discussion, I asked Mike for a definition of a planet. As you will hear, it has changed over the years.  In talking about a new planet definition, he mentioned the many types of planets, star systems with planets, the rogue planets and more.  Listen to how he defined a planet and tell us what you think by posting a comment on TSS blog.  As a result of his planet definition, I asked him what grade school students learn about planets today and what their science teachers teach them about planets.  This was also interesting given he said he had young kids in school and could speak to this question at least from the perspective of the schools attended by his children. 

Tim in Huntsville send in an email asking if as a sign of biomarkers of sorts suggesting  extraterrestrial intelligence, could an astronomer from another star system detect above-ground nuclear bomb tests that happened last century on earth.  Our guest talked about the electromagnetic pulse and detecting for something like that.  He say they might be able to if they were looking for those types of signatures but an ET civilization may not be looking for the type of signatures left over by a nuclear bomb blast.  This is another discussion you don't want to miss.  Before the break, Adrian sent in an interesting email asking about detecting metabolic type atmospheric biomarkers given certain characteristics and parameters.  I read Adrian's email in full on air so again, don't miss his question and Mike's reply.

In the second segment of our program, I asked our guest about descriptions of exoplanets made of diamonds that he has in the book.  This led to a good discussion about carbon and high pressure leading to the conclusions that many exoplanets with very high amounts of carbon and very high pressures are composed of diamonds. He reported this in his book regarding the exoplanet 55 Cancri E known as the Diamond World. the 55th brightest start in the constellation Cancer is according to our guest, an ordinary star some 40 million light years from Earth. This star has a complex planetary system surrounding it including 55 Cancri e, first detected in 2004.  It is referred to as Diamond World.  Don't miss his explanation of this.

I asked our guest about exoplanets with possible hydrocarbons given the presence of carbon and high pressures.  Dr. Summers explained that while hydrocarbons are formed under high Earth pressure, the exoplanet pressure he was talking about was many multiple times higher than Earth pressure and that in such cases, the hydrogen would separate and likely be blown away leaving just the carbon.  It too was an interesting discussion you will not want to miss.

Later in the segment, I asked our guest what he thought was the most unusual exoplanet. He said there were exoplanets almost entirely consisting of water.  Some might even have a steam atmosphere.  Our guest had much to say about unusual exoplanets.

Adrian sent in another email, this time a comment about organic life.  His bottom line comment was " If one is liberal with a definition of life forms, then projecting our own technological future might lead to an engineered semiconductor type of life possessing an AI type of life capable of reproducing itself and eventually populating a civilization."  Don't miss what Dr. Summers had to say in response to this email from Adrian.

Another listener asked if our study of exoplanets helped us on Earth.  Mike said it certainly did.  Let him count the ways for you in his response.

Paul sent in a note asking about our living in a simulation and if so, why bother with all this stuff.  Mike had an interesting response to Paul.  Again, don't miss it.  He was familiar with the simulation argument but said he had no way to studying or confirming anything like that.  Before we ended the program, Cindy sent in a note about noisy Earth and the fact that some advanced civilization may not want to be detected so they run silent. Mike had lots to say about a noisy Earth, including the fact that we are not as noisy today as we once were.  Don't miss this final discussion.

Before we ended our show, our guest said there was lots more to discuss with exoplanets. For example, what we are learning about the origin of life, the huge diversity that exists with planets, the role of our imagination.  He also said a follow up book on Exoplanets was already being written as the knowledge about exoplanets was changing so fast the current book would be out of date in two years or so.

Please post your comments/questions on TSS blog.  You can reach Dr. Michael Summers through me or his faculty page at George Mason University.

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"Exoplanets," a new book by our two guest authors

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