Alpha Centauri Labeled

Asteroseismic studies, chromospheric activity, and stellar rotation (gyrochronology) are all consistent with the Alpha Centauri system being similar in age to, or slightly older than, the Sun. Asteroseismic analyses that incorporate tight observational constraints on the stellar parameters for the Alpha Centauri stars have yielded age estimates of 4. 85±0. 5 Gyr, 5. 0±0. 5 Gyr, 5. 2 ± 1. 9 Gyr, 6. 4 Gyr, and 6. 52±0. 3 Gyr. Age estimates for the stars based on chromospheric activity (Calcium H & K emission) yield 4. 4 ± 2. 1 Gyr, whereas gyrochronology yields 5. 0±0. 3 Gyr. Stellar evolution theory implies both stars are slightly older than the Sun at 5 to 6 billion years, as derived by their mass and spectral characteristics.



The existence of ample amounts of hydrogen in the subsurface ocean of Enceladus indicates that microbes--if any exist there--could use it to obtain energy by mixing with carbon dioxide dissolved in water. This particular chemical reaction, termed methanogenesis, because it manufactures methane as a byproduct, may have been of critical importance in the emergence of life on our planet. The astronomers found that larger craters, which excavated pits much deeper into the Moon's surface, only increased porosity in the underlying crust. This indicates that these deeper layers have not reached a steady state in porosity, and are not as fractured as the megaregolith. Many people believe that astrology only concerns the sun. This is due to the Western world view of astrology, which has taken on the form of Zodiac horoscopes. However, in truth the study of astrology goes well beyond sun signs.