KU Astrobiophysics

Astrobiophysics is concerned with the effect of astrophysical processes on life on Earth, as well as effects on possible life elsewhere. We distinguish it from astrobiology, which is concerned with finding extraterrestrial life. A wide variety of research areas meet here, including astrophysics, astronomy, biochemistry, evolutionary biology, paleontology, atmospheric science , and a host of others. We are funded by NASA for one current project.

Our work in this area began in 2003 with an exploration of the effect on the Earth of radiation (X-rays and gamma rays) from a gamma-ray burst in our Galaxy. From there it has expanded and diversified. Our projects fall into three main areas, which we explore below in a tree structure with links.

I. Astrophysical Ionizing Radiation Events--the Effect on Our Biosphere

We probably all have heard of solar flares, when we get a little extra dose of radiation from the Sun. There are also occasional much more powerful flares. Supernovae go off in our Galaxy, and if they happen to lie within a few tens of light-years, the effects can be disastrous. Some supernovae produce gamma-ray bursts, in which the radiation is collimated into narrow jets that can easily do serious damage from halfway across the galaxy. Estimates suggest that such events should befall the Earth, with potentially severely damaging events likely on a timescale of a few hundred million years. Our first efforts, and still the most prolific, lie in this area. In the sections below, we explore several different likely or possible kinds of radiation events and their effects on the Earth.

  • We have published a review and census of threat levels and rates from various kinds of sources, in case you wish to see "the big picture." (Our "big picture" is also on the cover of this, the May 2011 issue of Astrobiology.) This work was briefly discussed in Nature Physics.

    Gamma Ray Bursts in Our Galaxy

    Effects of Cosmic Rays on the Atmosphere and Irradiation at Sea Level: Lookup Tables for Researchers

    Nearby Supernovae

    Major Solar Flares

    Cosmic Rays from a Galactic Shock Wave

    II. Work Related to asteroid/comet impacts as possible triggers of mass extinctions.

    Our study of comets and atmospheric chemistry

    Results on a 27 Myr Periodicity in Extinction and the Hypothesis of a Dark Solar Companion (Nemesis)

    III. A 62-Million Year Cycle in Fossil Biodiversity

    Analysis of the fossil and geochemical record

    Some events and media coverage related to our research...

    2007 American Astronomical Society workshop "Astrophysical ionizing radiation sources and their impact on life"

    For more information look here.

    Astrobiology Science Conference, 2008

    We organized one of the 39 parallel sessions. Two of the talks pegged as most exciting in a review by Astrobiology Magazine were in our session: The Habitable Galaxy

    National Geographic TV show features our work

    Our work on the topics below was featured prominently in a National Geographic Television program entitled "Extinctions". The program will be rebroadcast periodically. Research in our group constituted approximately the last third of the program.
    Their summary: "Planet earth teems with life, but imagine in disappearing in one go: a victim of catastrophic events that leave the planet almost uninhabitable. Naked Science travels back in time to examine three of the largest mass extinctions that decimated life on the planet in the past. What caused these wipe-outs and could they happen again in the future, threatening our very survival? Worse still, are we already in the middle of a mass extinction--not one created by nature, but by man? This program unravels the clues and likely suspects behind the dinosaur, Permian, and late Ordovician wipe-outs. Even given human adaptability and know-how, would we fare any better than the previous victims of these disasters? Could we be wiped out? We discover that we are not as safe as we'd like to think."

    Weather Channel presentation features our research

    In spring 2013, our GRB research was the focus of one episode of the series "Forecasting the End". The show is repeated occaisionally. A short clip is available here. There is also a KU press release available.

    Want to learn more, get involved??

    Academic Links and opportunities

    Attend our informal seminar.

    Undergraduates can minor in Astrobiology. Here is the handbook listing.

    Opportunities exist for students to be involved in research at both the graduate and undergraduate level. We have a block of supercomputer time at the National Center for Supercomputer Applications for those computations too large for local workstations. We maintain an active net of collaborators especially including NASA Goddard Space Flight Center, in their Astroparticle Physics Laboratory and their Laboratory for Atmospheres. We have an active project with the Photobiology and Solar Radiation Lab at the Smithsonian Environmental Research Center. The SWIFT mission is providing new information about Gamma-ray bursts, including much-needed data on their rate in the "recent" Universe (since the Earth formed).

    Our recent research publications can usually be found here, enter "melott" in the author line.
    Older published research is listed elsewhere.


    KU Faculty:

    KU Student Alumni

    Some recent collaborators:

    Last Updated: October 10, 2017