Vastly Different Worlds (WW114 - Season One Finale!)

Season One of Western Worlds clues up tonight with my interview of Dr. Jaymie Matthews (pictured above) of the University of British Columbia. We'll be back on Monday, July 30th for Season Two, starting off with a discussion of the Mars Science Laboratory.

In his work as an anthropologist, the famed scientist Jared Diamond is known to express his fondness for the idea of a "natural experiment." What he means by this is that some systems are so large and complex and the ramifications of changing variables so severe that it would be impossible to simulate these systems in the laboratory or the real world. So, instead, what we do is to look at the world around us and its history. For significant events, if we can determine their proximate and ultimate causes and understand the variables in play we can understand the relationship between cause and effect. For instance, we don't need to go out and remove all the trees from an island to understand what deforestation does to the culture living there - the history of Easter Island tells us this.

Similarly, in Astronomy we are lucky that there are examples of just about every structure that exists both today and, through the finite speed of light, in the past. We didn't have to reconstruct the positions of all the near stars to understand what a galaxy looks like from all angles, there are examples of every type in every orientation out there, just waiting to be observed. And we understand the life-cycle of stars from birth to death even though the process requires more time than life has been on Earth because we can see examples of every stage out there.

Similarly, we can use Exoplanets to tell us what our own solar system and our own planet would be like were the conditions a little bit different. Earlier this year we heard from Nikku Madhusudhan about what might happen if Carbon exceeded Oxygen in abundance. This episode, we explore the full gamut of possibilities from planets both nearer and further from their parent stars than we, some with highly eccentric orbits that give them phenomenal seasons. This tells us about climate in general and its ability to regulate planetary temperature and weather. For that reason, this episode is entitled "Vastly Different Worlds." And like what we have learned from studying the clouds on Jupiter and, yes, the dunes on Mars, it can improve our understanding of our own planet and the processes that affect the world we experience.

It's a great way to cap off our season! And like the interview with David Southwood, there's a little something for everyone in the work of Dr. Matthews. As usual, my on-air intro is under the cut. After you listen to this episode, be sure to head on over to our Survey and help to pick out what episodes we'll air over the summer. Have a great couple of months and don't forget to make World Enough and Time for us again the week before Curiosity lands on Mars 10 PM EDT on Monday, July 30!

Diamonds on the Blackest Velvet (WW111)

Tonight's guest on WW is Nikku Madhusudhan (shown above in a photo by Beverly Schaefer) as we return once more to the topic of extrasolar planets. It's a fascinating field that has grown in leaps and bounds since the first planets were observed around pulsars in the ealy 1990s and around a main sequence star in 1995. Since that time our techniques have expanded and the variety of planetary systems is added to almost daily.

Astoundingly, we can now deduce details about the atmospheres of some of these extrasolar planets, but only the ones relatively large and relatively close-in around brighter stars. But even in this small subset of the infamous "hot jupiters" there is amazing variety. A good part of Dr. Madhusudhan's fame comes from confirming the existence of planets for which Carbon is more abundant than oxygen. Such places were long theorized to exist because Oxygen and Carbon are produced in similar quantities by the proceses in stars that create elements heavier than hydrogen. This "nucleosynthesis" produces a characteristic pattern that we can observe in the abundances of elements within our own solar system (from wikipedia and shown below):

Take a close look. You'll notice a few things. First, the elements created in the big bang, Hydrogen and Helium Dominate - we have not yet come close to processing all of the material in the universe through stars. Secondly, you'll notice the stair-step pattern favoring even-numbered elements. This comes from the relative ease of building up heavier nucleii from "alpha particles," helium-2 nucleii and the greater stability of the nucleii thus formed. But the abundances fall off as the atomic number increases because it gets harder and harder to form larger and larger nucleii since more energy is required. In particular, beyond Iron, nuclear fusion does not yeild any energy, and so you get a pile-up that allows Iron to stand up above the pack.

What about Carbon and Oxygen? Well, these are synthesized largely through an efficient nuclear fusion process called the CNO-cycle in stars a bit more massive than the sun and up. Depending on the specific circumstances of the stellar furnace in question, either one of Carbon or Oxygen can come out a bit ahead. In the building of our own solar system, it was Oxygen. And so we have a solar system whose solids are composed mainly of ices (H2O) and silicate-bearing rocks (SiO4). By weight, Oxygen is not just a significant part of our atmosphere but comprises nearly 60% of the Earth's solid matter too.

Had the balance been different, a system of carbon compounds with different properties would have resulted. By showing that such systems do, in fact, exist Dr. Madhusudhan has expanded our view of the universe and the kinds of variety that exists out there. I hope you enjoy listening to his interview as much as I did. As always, a transcript of my intro is under the cut.

The Landscape in the Sky (WW106)

This Monday past marks the first interview of Parshati Patel, as she becomes the fourth member of the WW crew to try her hand at interviewing! She certainly couldn't have picked a better subject then Dr. Travis Barman (pictured above) of the Lowell Observatory and the results speak for themselves. If you haven't had the chance to listen, drop by the WW page and pick up a copy of the interview!

The solar system has, for a long time, been our own backyard to astronomers - out beyond our home but not as exotic or enticing as that which lies beyond. But, exo-planets are an interesting cutting-edge convergence of Planetary Science and mainstream Astronomy each of which counts this field as their own. It's a productive rivalry with "Planetary Science" missions like Kepler, a space mission currently conducting a planetary census, coordinating with "Astrophysics" telescopes on the ground to confirm discoveries of new worlds. The statistical results then get put into models, such as those of the Nice group, that help to tell us why our own solar system looks the way it does today. By understanding the initial conditions required to make our solar system "work" and how ours differs from others, we can get a handle on the process more generally.

It's a fascinating study and the explosion in planets over the last decade is nothing less than breath-taking. The expansion in techniques is no less so. While it may be awhile before we get to see them up close and know them the way we do our own solar system, Dr. Barman's direct images of exoplanets far from their parent stars brings to mind what Uranus and Neptune might have looked like a century ago. Who knows what the future in this fast-breaking field will bring? I hope you enjoy the episode, and, as always, my introduction is underneath the cut.

Introducing: Western Worlds

The short-form logo for the newest AFM*Original program, "Western Worlds."

For those of you who enjoy York Universe (you can check out our new website here) I am happy to tell you that there is a spin-off show on the way and it starts at 10 PM ET on Monday, February 27th! The name of the show is "Western Worlds." Here's the format: the show is thirty minutes long and each will feature an interview with an engineer, researcher or educator working in the planetary sciences as interviewed by one of our capable co-hosts. That's the first twenty minutes. The last ten minutes will feature a round table with several co-hosts as we draw upon our own individual expertise to understand what the interview subject's work means to each of us.

The show is being co-produced by Alyssa Gilbert of the Centre for Planetary Science and Exploration (CPSX) at the University of Western Ontario and by Michael Foerster at Astronomy.fm . I'll be doing the day-to-day showrunning. We've also got a great crew of undergraduate, graduate and postgraduate scholars who will be generating the interviewing, editing and discussion content that we will share with you all each and every week.

We've got several episodes which are nearing completion and I will be delivering these to AFM this week. As a Canadian Planetary Scientist, I'm excited to have a radio home all our own and I look forward to sharing all the great work being done within our community with you all every Monday night!

Dr. Ralph Pudritz's CATP Seminar, January 14, 2011

Some of the previous work by McMaster's Ralph Pudritz, a member of the Origins Institute and CATP Speaker on January 14, 2011 (Image is from Amazon.com)

Dr. Pudritz's CATP Seminar was built around the work he has done understanding the thermodynamics of biomolecules on the early Earth. The reason that this is interesting is because life is known to rely heavily on certain very specific compounds as building blocks, but not others. While there are almost an unlimited number of possibilities for carboxylic acids (which amino acids resemble) only 20 different amino acids are used by all life with an additional two found in some organisms, but not others.

Adding to the mystery is chirality, a sort of molecular handedness. Just like you could tell a right hand from a left one, if you found it on its own, all amino acids (with the exception of glycine) have at least two possible configurations. Since both forms are very similar, chemically speaking, nature produces essentially equal amounts of each through abiotic (that is, non-biological) processes. But where life is concerned, only one form is actually used. This incredible selectivity of biological processes is surprising, and sufficiently odd that it has often been talked about as a biomarker; a smoking gun that we have run across a biology or its byproducts.

Dr. Paul Wiegert's PSURF, January 21, 2011

(Sorry for the delays! Fuller updates are on the way!)

Can life, or at least meteorites, travel between the stars? If so, how would we know where they had come from? Paul Wiegert addressed this question in his PSERF talk on the 21st of January, 2011

This week's PSURF Talk (a link will be posted here once it is online) dealt with a topic of eminent importance to us Astrobiologists - the concept of panspermia. What is panspermia, you might ask? Well, basically it describes a theory wherein life does not need to originate separately one each body where it is found. Life could originate at one place, at one time, in conditions that are truly extraordinary and then propagate to other worlds and other situations. If you believe the theory, then there is no need to be bounded by the conditions of the early Earth when considering life's abiotic origins. Instead, we can also consider whether life got an easier start on Mars, or inside a differentiated asteroid (this was discussed extensively at the York University Physics and Astronomy Journal Club last week; last week's CATP seminar, which I will post soon!) or even within Giant Molecular Clouds.

Of course, wherever life formed, it needs some way to get from there to here. This is where Paul Wiegert's research comes in. Paul is part of the meteor group at UWO in Physics and Astronomy. Together, this group operates a network of ground stations which examine a particular volume of sky in Southwestern Ontario for meteors. From the triangulation that the network makes possible, it is possible to back out the trajectory of the incoming particles, their speeds, and if they are big enough (fireballs) where any meteorites might land.

Dr. Jonathan Fortney (Conversations at the DPS, profile 6)

Dr. Jonathan Fortney enjoys a field lecture and the start of a life in Planetary Science near Dry Falls, Washington State in 2002. Photo by Jason Barnes.

Well folks, we've come to the end of our journey. I'll have some additional insights from DPS to post later in the week, but for now please enjoy the short blurb below of Dr. Jonathan Fortney, the last of the DPS interviews. In some ways, Jonathan is our most distinguished guest, as he won the DPS's Urey Prize as the top early career researcher this year. You'll have to forgive him if his voice sounds a little raw - I snagged him right after he gave his lecture! Even though Jonathan got his PhD at the University of Arizona, I can't say that I knew him well while he was there. His last year and my first year were the only ones that overlapped, so in some ways we were only ships passing in the night.