Monthly Archives: December 2011

astronomy

Cosmic Consciousness

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We are a Way for the Universe to Tell Its Story

Galaxy history, as seen by Hubble Space Telescope. NASA/ESA, Windhorst, S. Cohen, M. Mechtley, and M. Rutkowski (Arizona State University, Tempe), R. O'Connell (University of Virginia), P. McCarthy (Carnegie Observatories), N. Hathi (University of California, Riverside), R. Ryan (University of California, Davis), H. Yan (Ohio State University), and A. Koekemoer (Space Telescope Science Institute).

Occasionally I’ve written about what I think of as the scientific history of the universe. That’s the story of the mechanics of the cosmos starting with the Big Bang some 13.7 billion years ago and tracing the creation of the first stars and galaxies and eventually the planets, and then on to life. It’s a compelling history and astronomers and cosmologists are still inking in the details as they learn more about things like dark matter, dark energy, and so on. I like the story, mostly. What I don’t like about it is that it seems to put humans at the top of the evolutionary chain that stretches back all those billions of years. And, that’s most emphatically NOT what cosmic history is about. There is bound to be other life out there, other planets teeming with biota of some kind–and each of those is also part of the evolutionary tree.

There’s another way to look at this bounding evolutionary story, and that’s from the standpoint of something that the late Carl Sagan once said, “We are a way for the universe to know itself.”  I don’t think he meant just you and me and the tree on the corner.  He meant Earth and all the structures it contains and the life it bears.  “We” in this context are part of a living, breathing construct that encompasses Earth and all the stuff it contains. And, in our DNA, in the structure of the rocks and trees and lakes and continents and seas and deserts and microbes and all the life that surrounds us, is encoded the story of the universe. Our bodies contain elements first created in the Big Bang, and others that were created and cycled through one or more stars. Our planet has the same makeup. That makes us part of the cosmos that I’m not sure we fully appreciate yet. Otherwise, we wouldn’t be treating each other and our planet as if all were disposable.

What brought all this to mind tonight was a program currently appearing on PBS called the Journey of the Universe. It is billed as an epic story of cosmic, Earth, and human transformation, and it is a very nicely done exploration of the evolution of the universe and our place in it,and the evolution of our consciousness along with everything else. It’s both a film and book project, hosted by evolutionary philosopher Brian Thomas Swimme and historian of religions Mary Evelyn Tucker.  Their story is nicely woven, bringing together scientific discoveries in astronomy, geology, and biology and infusing them with humanistic insights concerning the nature of the universe. I found it a very poetic and compelling program to watch, and as I did, I wondered just what sort of universe has evolved that allows us to use the miraculous consciousness we’ve all evolved with to do great things like explore the cosmos, create art and music, create families, and learn to live with other living beings on the planet. Unfortunately, some people among us also use that same consciousness to do things like trash the planet, exploit animals, kill other humans, use spiritual beliefs to foster hate, and use political power to foster misogyny, ignorance, and fear.

When I look at the stars, I see where we came from. I see where we’re going. And, I often wonder (as the authors of this lovely program do), what we are going to become—and I see what we will have to overcome in order to move forward in step with the evolution of the cosmos.

If you’re interested in a spirited, open-minded look at the cosmos, us, and our place in it, check out this program. The web page I linked to above has a list of screenings on PBS and in various towns and cities. It’s worth checking out. It might just give you some pause for thought.

extrasolar planets, Kepler mission

Kepler’s Hits Just Keep Coming

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A Near-Earth-sized Planet in the Goldilocks Zone

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. Image credit: NASA/Ames/JPL-Caltech

The search for extra-solar planets that the Kepler mission is doing just keeps cranking out discoveries. The latest one is special: the first planet that is close to the size of Earth that orbits its star in the so-called “Goldilocks zone”. Essentially, that’s the region around almost any star where liquid water could exist on the surface of a planet that happens to be orbiting ‘in the zone’.

The planet is called Kepler-22b, and it is about 600 light-years away from us. While the planet is larger than Earth, its orbit of 290 days around a Sun-like star resembles that of our world. The planet’s host star belongs to the same class as our Sun—a G-type star which is actually slightly smaller and cooler.

Now, this discovery of a planet in the right place around its star is interesting because—as we all know—water is one of the three requirements necessary for life to exist: water, warmth, and organic material (food). So, finding a planet in the sweet spot is a big first step in locating life on other worlds.

It does NOT mean that Kepler has found life. It just means it has found a planet in the right place to support conditions that might allow life. That sounds hand-wavy, but this is the way discoveries work. You have to figure out if the environment is right for life, and then go about trying to understand that environment. Now, we have to study the planet further to see if water exists there.  It could be done by watching as the planet orbits between us and the star, and studying the star’s light as it passes through the planet’s atmosphere.  That is a technique called spectroscopy, and it means that astronomers detect the light, let it pass through a “super-prism” that breaks up the light into its component wavelengths, and then study the data to see if it indicates that water is present.  It would most likely be the presence of water vapor.  The amount you find, along with some other characteristics, tell you about the amount of water in the system.  So, Kepler’s discovery is  a big first step.

Kepler is an interesting observatory. It doesn’t take pictures.  It’s mainly interested in something called “light variation”.  That is, it discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars.  If a it sees a periodic dip in the light intensity coming from a star, then there’s a very good possibility that a planet is crossing in front of the star (from our point of view), or “transiting” it.  Kepler requires at least three transits to verify a signal as a planet. (And, by signal, we mean “a dip in the light intensity”.)

Once these candidate planets are announced, then a series of ground-based telescopes and the infrared-sensitive Spitzer Space Telescope look at them and provide data that helps astronomers verify that these things are planets. It’s a long-term task and one that’s keeping astronomers busy. Kepler finds many candidate planets, and each one needs to be meticulously checked out.  Kepler has found 2,326 planet candidates. Of these, 207 are approximately Earth-size, 680 are super Earth-size, 1,181 are Neptune-size, 203 are Jupiter-size and 55 are larger than Jupiter. Today’s announced discovery is one of only 48 stars (of the many thousands  that Kepler has studied) that have planets in their habitable zones. It is the first planet in a habitable zone that is near-Earth-sized, and that’s exciting. I hope it also means that there are many more of them out there, just waiting to be detected!  Stay tuned.