Are cell mutations always bad? A mutation is a change in the genetic material of an organism. We are made from trillions of cells, each with a nucleus composed of DNA â a set of instructions that tells the cell what to do. Cells copy themselves with astonishing accuracy, but every now and then a piece of code is copied incorrectly.
Seven eclipses occur in a minimum of 12 lunar months (about 354.37 days). Given that the calendar year is only about eleven days longer than 12 lunar months, the first of the seven eclipses has to come in early January for the seventh eclipse to occur before the end of the year.
With Animations: Solar Eclipses 1900-2099. Solar eclipses can only occur during a new Moon, when the Moon moves between the Earth and the Sun and the three celestial bodies form a straight line: Earth-Moon-Sun. There are 3 kinds of solar eclipses: total, partial, annular. There is also a rare hybrid that is a combination of two eclipses.