I’ve spent the last couple of days catching my breath following a wonderful mini vacation + science conference that my significant other (“StarMan”) and I attended last week. We really made the most of the trip, in a way that I wished we lived our life, every day. For example, we opted to drive to Long Beach rather than just fly, and we took a route down the awesome, vertigo-inducing Pacific Coast Highway, passing through Big Sur. On the day we arrived in Los Angeles, we went to the La Brea tar pits, a place that I’ve wanted to see since I read about them as a 10-year-old paleontologist wanna-be!
We finally checked into our hotel in Long Beach and spent Monday through Thursday attending the American Astronomical Society conference, which is a kind of astronomers’ Super Bowl. The underlying theme this year seemed to be “All Things Exoplanets”, given the numerous presentations and press releases on the topic. What a change from, say, 20 years ago! An exoplanet is simply a planet (like the Earth, or perhaps a gas planet like Jupiter) that happens to be orbiting about another star (e.g., not around our star, the Sun). When I was getting my Ph.D., the total number of confirmed exoplanets was something like … three. Today, there are nearly 900 confirmed exoplanets, and that number is growing on a nearly daily basis!
By far, the highlight of the meeting was this: Earth-sized planets are plentiful in our Galaxy! This announcement is made possible due to the copious amounts of data coming from NASA’s Kepler mission, a program that I had the privilege of having been part of for a couple of years. The Kepler telescope has been staring at the same patch of sky, without blinking (much), for nearly 4 years, diligently monitoring the same 150,000 stars over that time period. What scientists look for in the Kepler data is the tell-tale sign of a planet passing (transiting) in front of its host star: a subtle dimming of one of those 150,000 stars that lasts for a couple of hours, which repeats with a distinct periodicity (for example, once a year). The degree of dimming tells something about the size of the planet (big planets block out more of the starlight as they pass in front of the star than smaller planets), and the duration and frequency of the dimming tells something about how far the planet is from the star.
The “holy grail” of exoplanets is to locate a planet that is about the same size as Earth (and therefore a rocky rather than gaseous planet), and that is just the right distance from the star such that water exists as liquid rather than as ice (too far from star, too cold) or as vapor (too close to star, too hot). This special distance around a star for which the temperature is just right for liquid water is referred to as the “Habitable Zone”, because where there is water, there could be life. If indeed Earth-sized planets are plentiful, as I heard in several presentations during the conference, then so must be habitable planets. We have now stepped into an era in which we can expect a scientific, rather than philosophical, answer to the question: Are we alone in the Universe?!
Well, nothing I could say would be more profound than that last sentence, so I’ll just leave you with some pictures documenting our little “work-cation”. Enjoy! (Note: click on the pictures to get the full-resolution image … they look better that way!)
Some sights along Big Sur:
A colony of elephant seals that we unexpectedly discovered:
The La Brea Tar Pits in Los Angeles:
The route we took back home led us through the Carrizo Plains National Monument. The San Andreas fault passes through this location, making its presence dramatically obvious, by displacing a creek that flows across it (see the annotated picture of the dry creek bed below. The purple arrows indicate the motion of the Pacific plate relative to the North American plate, with the fault laying somewhere between!) The second pic is of Soda Lake, made white by the salts left behind by evaporating water. The fault activity has rendered this valley without the ability to drain, so this lake is like a big clogged sink — all the rain water in the plain collects there and leaves only via evaporation.