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Sky & Telescope article: Where have all the aliens gone?

January 20, 2010

If intelligent life is common in the galaxy, then the fact that we have not yet observed any extraterrestrials raises the question: where are they? The upcoming March issue of Sky & Telescope magazine features an article written by myself and Seth Baum where we discuss how the conspicuous absence of extraterrestrials may relate to the problem of sustainable development on Earth.

Funny story, we were initially slated for the January issue (we even made the table of contents), but a printing error lost the last 10 pages which sadly included our article. Nevertheless, the Sky & Telescope staff are excellent people to work with and made a fast turnaround. Be sure to check out the March issue!

A Hazy View of the Early Earth

February 6, 2009

My MS paper, “A Revised, Hazy Methane Greenhouse for the Archean Earth”, just appeared in the journal Astrobiology! You can view a PDF of the article on my research page.

We argue that the warm, ice-free climate of the early Earth (2.8 billion years ago) was maintained by a water vapor/carbon dioxide/methane/ethane atmospheric greenhouse effect that offset the ~20% reduction in solar luminosity from the faint young sun. Furthermore, a stabilizing feedback between life and the climate system may have resulted in a thin stratospheric organic haze that maintained above-freezing temperatures and shielded ultraviolet radiation. An excellent write-up of our work is available at The Planetologist.

I’ve given this talk several times over the past couple years, most recently on the Forum for Astrobiology Research (which should eventually be available as a podcast), and it feels good to finally see the paper come out.