Almanac

This section is essentially a calendar giving the dates of the new and full moon, eclipses, transits, and the principal aspects of the naked-eye planets for a period of 10 years (2006-2015). Some of these events can obviously be seen from any part of Earth. Others, such as the eclipses of the Sun and Moon and the transits of Venus and Mercury, are visible only from certain continents or regions. In these cases, the Almanac indicates from which parts of the world the phenomena can be seen.

Eclipses of the sun occur when the Moon passes in front of the Sun and blocks off its light. Total eclipses are visible only from a narrow band within which the Moon covers the entire Sun, but partial eclipses are visible over a much wider area. When the Moon is near the most distant point in its orbit from Earth, it may not cover the Sun completely, leaving a ring, or annulus, of light surrounding it at mid-eclipse. This is known as an annular eclipse. Rarely, an eclipse can be total at the middle of the eclipse track, but annular at either end. Total or annular eclipses last only a few minutes, but partial ones can last up to three hours. Never look directly at the Sun; see p.83 for guidelines on methods of observing the Sun safely.

Eclipses of the Moon occur when the Moon enters Earth's shadow and can last up to four hours. Even when the Moon is totally eclipsed, it does not disappear entirely, since some sunlight reaches it via Earth's atmosphere.

On rare occasions, the inner planets Mercury and Venus pass in front of the Sun as seen from Earth, an event known

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