Starts With A Bang #120 - Exoplanet biosignatures

About this episode

This episode discusses the search for life on exoplanets, focusing on the claims surrounding K2-18b and the scientific evidence for biosignatures.

Out there in the Universe, somewhere, a second example of an inhabit world or planet likely awaits us. It could be some other planet or moon within our own Solar System; it could be a spacefaring, interstellar civilization, or it could be an exoplanet around a different parent star. Although the search for life beyond Earth generally focuses on worlds that have similar conditions to Earth, like rocky planets with thin atmospheres and liquid water on their surfaces, that's not necessarily the only possibility. The truth is that we don't know what else is going to be out there, not until we look for ourselves and determine the answers. And yet, if you've been paying attention to the news, you might think that super-Earth or mini-Neptune type worlds, such as the now-famous exoplanet K2-18b, might be excellent candidate planets for life. Some have even gone as far as to claim that this planet has surefire biosignatures on it, and that the evidence overwhelmingly favors the presence of life within this planet's atmosphere. But the science backing up that claim has been challenged by many, including our two podcast guests for this episode: Dr. Luis Welbanks and Dr. Matthew Nixon…

People in this episode

Host: Ethan Siegel

Guests: Dr. Luis Welbanks, Dr. Matthew Nixon

Topics covered

• exoplanets
• biosignatures
• search for life
• K2-18b
• science of habitability
• interstellar civilization

Keywords

• exoplanets
• biosignatures
• K2-18b
• life beyond Earth
• rocky planets
• mini-Neptune
• super-Earth
• interstellar civilization

Mentioned in this episode

Books & works: Starts With A Bang

Places: Earth, Solar System, K2-18b, Universe

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