An M-class dwarf star such as Gliese 581 has a much lower mass than the Sun, causing the core region of the star to fuse hydrogen at a significantly lower rate. From the apparent magnitude and distance, astronomers have estimated an effective temperature of 3200 K and a visual luminosity of 0. 2% of that of the Sun. However, a red dwarf such as Gliese 581 radiates primarily in the near infrared, with peak emission at a wavelength of roughly 830 nm (estimated using Wien’s displacement law, which assumes the star radiates as a black body), so such an estimate will underestimate the star’s total luminosity. (For comparison, the peak emission of the Sun is roughly 530 nm, in the middle of the visible part of the spectrum. ) When radiation over the entire spectrum is taken into account (not just the part that humans are able to see), something known as the bolometric correction, this star has a bolometric luminosity 1. 3% of the Sun’s total luminosity. A planet would need to be situated much closer to this star in order to receive a comparable amount of energy as the Earth. The region of space around a star where a planet would receive roughly the same energy as the Earth is sometimes termed the “Goldilocks Zone”, or, more prosaically, the habitable zone. The extent of such a zone is not fixed and is highly specific for each planetary system. Gliese 581 is a very old star. Its slow rotation makes it very inactive, making it better suited than most red dwarfs for having habitable planets.
The GRAIL mission determined the internal structure of the Moon in great detail for nine months during 2012. Armed with this the new information, GRAIL astronomers were able to redefine the sizes of the largest impact basins on the lunar surface. Phases of the Moon. The moon cycles 13 times a year through phases, each of which influence us just like the pull of the tides. It starts with the New Moon, which carries the energy of new beginnings, this is a great time to focus on stepping into something new. Then the Full Moon, Signifies the time of the completion of a project, and finally returns to the New Moon again. This entire cycle occurs over a period of 28 days, and yes, there is no mistaking it, this is the same as women's menstrual cycles, women tend to be much more connected to the moon than men. In the Eastern world, such as in China and India, the moon is actually the primary consideration in studies of astrology. The moon signs and cycles are used to determine the best time for activities, and is a part of daily life. This may seem backward to some, but actually results in more accurate predictions in many cases than Western astrology can ascertain.