Yesterday, after driving my morning route, I jumped in my car and traveled to downtown Chicago for the third and final noontime lecture on extraterrestrial life co-sponsored by the Adler Planetarium and the Chicago Temple. (I missed the second one, on what extremophiles are teaching astronomers about the possibility of life beyond Earth. BTW, links to both institutions appear in my post of October 25.)
Once again, the lecture was a real treat.
Dr. Grace Wolf-Chase, an Adler astronomer and senior research associate at the University of Chicago, spoke on “Searching for Life in an Evolving Universe.” Wolf-Chase studies the early stages of star formation and the effects of outflows from newly formed stars. Her presentation touched on these subjects, but most of her talk focused on how astronomy has become one of the most diverse multi-disciplinary fields in science today, using a wide range of sophisticated technologies to expand our understanding of how planets form around stars and how this process might yield habitable worlds.
Today the search for exoplanets is one of the most energetic specialties of astronomy. The first exoplanet, a largeJupiter-class body found orbiting a Sun-like star called 51 Pegasi, was discovered in 1995. As of this evening, 322 exoplanets have been identified using a variety of techniques. That’s 322 and counting.
For those interested in knowing the real time running total, Wolf-Chase referred her audience to The Exoplanets Encyclopedia, which not only keeps track of the number, but also provides a wealth of information on all things exo-.
Another strong resource is NASA’s own Astrobiology Institute (NAI), formally established in 1997 but loosely organized a couple of years before then. It’s mission follows that of astrobiology itself:
“The mission of astrobiology is to study the origin, evolution, distribution, and future of life on Earth and in the Universe.
Astrobiology shares with other space related science programs a broad range of research interests. Astrobiology encompasses the understanding of biology as a planetary phenomenon. This includes how planetary processes give rise to life, how they sustain or inhibit life, and how life can emerge as an important planetary process; how astrophysical processes give rise to planets elsewhere, what the actual distribution of planets is, and whether there are habitable planets outside of our solar system; a determination of whether life exists elsewhere and how to search for and identify it; what the ultimate environmental limits of life are, whether Earth’s biota represent only a subset of the full diversity of life, and the future of Earth’s biota in space.
The mission of the NASA Astrobiology Institute is to further our understanding of these profound questions by:
carrying out, supporting and catalyzing collaborative interdisciplinary research;
training the next generation of astrobiology reseaerchers;
providing scientific and technical leadership on astrobiology investigations for current and future space missions;
exploring new approaches using modern information technology to conduct interdisciplinary and collaborative research amongst widely-distributed investigators;
supporting outreach providing scientific content for K-12 education programs, teaching undergraduate classes, and communicating directly with the public”
I’ve contributed to and written a few mission statements in my time. None as “far-reaching” as this one.
Something else Wolf-Chase accomplished was giving her audience a sense of the cosmic scale associated with the closest known exoplanet. Phoning home from it would require more than a 10-year wait before the message (“Wish you were here?”) is received. In contrast, a message phoned-in from the moon would take about one second. From Mars, 10 minutes.
Current investigations of known exoplanets primarily focus on detecting evidence of an atmosphere, oxygen, liquid water, and methane – and then ruling out alternate explanations for them if/when they’re detected.
The search is certainly no small task when one considers our sun is just one of more than 200 billion stars comprising the Milky Way galaxy. Putting this in even more dramatic perspective, the Milky Way is only one of perhaps 80-100 billion galaxies in the presently observable universe.
That’s a lot of real estate.
And given the large quantity of organic material in space – in particular, polycyclic aromatic hydrocarbons (a term I never get tired of saying out loud) – I’m betting there are plenty of habitable zones on plenty of planets that human beings have yet to discover.
Coming next: Bringing the sacred home
Banner bus photo created by Dorothy Delina Porter