Sunday, January 06, 2013
The Milky Way: 100+ Billion Planets Minimum
The Milky Way contains, at the very minimum, at least 100 billion planets, and many of them are likely to be capable of supporting conditions favorable to life, a new study from Caltech has concluded. That alone sounds like an enormous number, but when you consider that the Milky Way is just one of countless galaxies, the number of planets in the Universe must be unfathomable.
Contrary to previous belief, the latest research by astronomers suggests star systems with planets are actually the norm across the cosmos. And the analysis only includes planets in close orbits around certain kinds of stars, meaning the massive estimate they have offered could yet be doubled.
The Caltech team made this conclusion based on analyzing the planets orbiting the Kepler-32 star, which contains five planets and which the scientists say is representative of the vast majority of stars in our galaxy. Kepler-32 is classified as an M dwarf, and scientists say three out of every four stars in the galaxy are M dwarfs, also known as red dwarfs, notes The Voice of America.
Based on their study of Kepler-32, the astronomers have calculated that there is, on average, one planet for every one of the approximately 100 billion stars in the Milky Way. Scientists say their estimate of 100 billion stars is conservative because it doesn’t take into account planets which may be orbiting further away from M dwarfs or planets orbiting other types of stars.