[LINK] "First Habitable Exoplanet Could Be Discovered By May"

[rfmcdonald]

The progress of astronomy in the past two decades always has amazed me. It's worth noting that by "habitability" the authors of the paper described seem to be talking about :potential habitability"; Earth-sized worlds in Earth-like orbits could be uninhabitable for one reason or another. Our Venus might arguably be a case in point.

“There is some wiggle room,” said Samuel Arbesman of the Harvard Institute for Quantitative Social Science, lead author of a new paper posted online and to be published in PLoS ONE Oct. 4. His calculations predict a 50 percent probability that the first habitable exoplanet will be discovered in May 2011, a 66 percent chance by the end of 2013 and 75 percent chance by 2020.

“This is, as far as we can tell, right around the corner,” said exoplanet expert Greg Laughlin of the University of California, Santa Cruz, co-author of the paper.

[. . .] Arbesman and Laughlin devised a mathematical way to define habitability using the techniques of scientometrics, the scientific study of science itself.

The pair considered a planet’s mass and its surface temperature at the points in its orbits when it is closest and furthest away from its star, and calculated which of these properties would be friendliest to liquid water (and, therefore, presumably, life). Then they plotted their habitability function on a scale of 0 to 1, where 0 is uninhabitable and 1 is a clone of Earth.

Next, the researchers turned to the exoplanets that have already been found. They calculated the habitability metric for 370 exoplanets whose masses and distances from their stars are relatively well-known, and plotted that number against the planet’s date of discovery. Then they used a statistical method called bootstrapping, which looks at subsets of data to get a better idea of the overall distribution, to extrapolate forward to a planet with a habitability value of 1.

The median date for this planet to make its grand entrance, they found, is early next May.