Sunday, February 20, 2011

Planets That May Have Life (If They Exist At All)

When scientists announced on September 29th that they had discovered a planet that could be inhabitable by living things, the Bohunk took it as a two-day early cosmic birthday present; I enjoy this stuff. Gliese 581g and Gliese 581f are both roughly 20 light years away from our own rock in the universe and are rare, like us, in that they occupy a space close enough but far enough away from their star to have liquid water. The discovery of these two planets was, frankly huge. Heretofore, only four known planets in the universe were known to exist in this “habitable zone”, and adding two more in a single study was, to science nerds, a startlingly big deal. Using radial velocity they studied the wobble of the nearby star produced by planets close by, something that utilizes the HARPS telescope in Chile and the HIRES spectrograph in Hawaii. Dr. Vogt, the discoverer, became one of the Bohunk’s heroes.

Until now. A team led by Rene Andrae, a very, very German scientist, is now claiming the planets do not exist and that other scientists have found no reliable evidence that these two planets even exist. They charge that Vogt made an incorrect assumption; Vogt’s calculations and research was based on the star having six planets with a circular orbit. In fact, the other scientists have essentially proven that the orbits are elliptical and that, because of the change in degrees, the gravitational wobble experienced by the star is the product of only these four planes on separate planes, not six on a predictable, even orbital path.

An artistic guesstimation of the possible planets that may or may
not actually exist.

Vogt has fired back with several papers and more data, and charges that the Bayesian techniques used by Andrae and a pal, Dr. Gregory, are inconsistent and largely unproven. Do these planets exists? Will we ever have the technology to see these planets, let alone visit them or look for life on their surfaces? We don’t know every thing, we know almost nothing. The universe, my friends, is the greatest mystery.

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