17 September 2011


Here's a followup on my Thursday report on the discovery of Kepler-16b, the first confirmed instance of a planet orbiting two stars (see image above). NASA's announcement (received after I posted my own) provides further details ~ "This discovery confirms that Kepler-16b is an inhospitable, cold world about the size of Saturn and thought to be made up of about half rock and half gas. The parent stars are smaller than our sun. One is 69 percent the mass of the sun, and the other only 20 percent. Kepler-16b orbits around both stars every 229 days, similar to Venus' 225-day orbit, but lies outside the system's habitable zone, where liquid water could exist on the surface, because the stars are cooler than our sun." The NASA announcement also introduces a term new to me ~ circumbinary, referring to a planet orbiting two stars. Cool.

Where the NASA description is somewhat dry and academic, Jennifer Ouellette's version Twin Suns Better Than One? is much livelier and more fun to read. Her tone is more conversational, with the bonus of providing more background on how planets are formed. Her less didactic approach is consistent with the mini-bio accompanying her Scientific American blog ~ "Jennifer Ouellette is a recovering English major turned science writer who loves to indulge her inner geek by finding quirky connections between physics, popular culture, and the world at large." Which might explain why she's one of my favorite science writers.

Expanding our focus, Matthew Bailes released an article this week which caught my eye ~ Diamond Planets, Climate Change, and the Scientific Method. Yes, his team has indeed discovered a planet that is made of diamond. The truly useful observation Bailes makes, however, is that there is no difference between the validity of discoveries in astronomy (which are rarely questioned or challenged, except perhaps by fellow astronomers) and the validity of discoveries in anthropogenic climate change (which are regularly questioned and challenged by the media and by individuals with little or no scientific training whatsoever, a very peculiar form of psychological denial). Bailes points out that the scientific method is employed in all science disciplines ~ "We make observations, run simulations, propose and test hypotheses, and undergo peer review of our findings. We get together and discuss and debate our pet theories, become friends and form a worldwide community. Of course we all make mistakes. But eventually the prevailing wisdom of the community triumphs and the field advances."

One consequence of our planet's global warming is the slow but inexorable rise in sea level, which has been documented for several decades. Among the first to face dire consequences are low-lying Pacific Island nations, which face inundation and the need for entire populations of human residents to relocate. This is but a precursor of the effects which will be felt in coastal areas around the globe, during the 21st century and beyond. Think about the flooding of New Orleans after Hurricane Katrina, multiplied across hundreds of cities and dozens of nations. Now realize that it could all have been avoided. Climate scientists have issued warnings about the effects of carbon dioxide and other greenhouse gas emissions since the 1980s. Sad to say, among the world's advanced nations, the U.S. remains among the last to publicly acknowledge the dangers, much less take radical steps to minimize them.

Well, from space perhaps our planet won't look much different. Witness the photo of the Southern Lights taken from the International Space Station by NASA astronaut Ron Garan (see image below). The constellation Orion is clearly visible. Thanks to Sheril Kirshenbaum for the link.

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