Post by Centaur on Apr 29, 2006 10:33:15 GMT -6
I create a new astronomical calendar each month that can be downloaded as your computer's desktop background wallpaper or printed to paper. It includes information on the naked-eye planets, the Moon and eclipses.
To see the calendar, click:
www.curtrenz.com/astronomical.html
For those interested in details, read on:
The lunar images and planetary visibility tables are topocentric and assume the observer is located in northwest suburban Chicago. Although, the calendar should well serve those in most northern hemisphere locations.
Each daily lunar image is depicted as it would appear on the night of the two dates it straddles. That includes not only the Moon’s phase/shape, but also the orientation of its illuminated portion and its apparent angular size. A waxing Moon is shown as it would appear midway between sunset and moonset. A waning Moon is shown as it would appear midway between moonrise and sunrise. The effects of earthshine and the oppositional flash are also demonstrated.
The phases described at the bottom of the page are calculated for more classical and intuitive definitions, rather than the simplistic ones necessarily employed in more recent times but before the advent of computers. Dark Moon is the moment during the monthly cycle in which the apparent lunar disk is least illuminated. Full Moon is when the disk is most illuminated. Half Moon comes when the disk is 50% illuminated. The percentage illuminated is printed under each image.
The apogee and perigee data are geocentric: megameters (thousands of kilometers) from center of Earth to center of Moon. Otherwise, if topocentric, this information might have seemed somewhat chaotic as the Earth's rotation causes a daily oscillation of the distance between a surface based observer and the Moon.
In the planetary tables, a morning star is a planet appearing in the sky before sunrise. An evening star is a planet seen after sunset. And a midnight star is a planet visible at local midnight (the moment midway between sunset and sunrise.) If a planet appears too close to the Sun to be easily observed, it is referred to as being lost in glare.
To see the calendar, click:
www.curtrenz.com/astronomical.html
For those interested in details, read on:
The lunar images and planetary visibility tables are topocentric and assume the observer is located in northwest suburban Chicago. Although, the calendar should well serve those in most northern hemisphere locations.
Each daily lunar image is depicted as it would appear on the night of the two dates it straddles. That includes not only the Moon’s phase/shape, but also the orientation of its illuminated portion and its apparent angular size. A waxing Moon is shown as it would appear midway between sunset and moonset. A waning Moon is shown as it would appear midway between moonrise and sunrise. The effects of earthshine and the oppositional flash are also demonstrated.
The phases described at the bottom of the page are calculated for more classical and intuitive definitions, rather than the simplistic ones necessarily employed in more recent times but before the advent of computers. Dark Moon is the moment during the monthly cycle in which the apparent lunar disk is least illuminated. Full Moon is when the disk is most illuminated. Half Moon comes when the disk is 50% illuminated. The percentage illuminated is printed under each image.
The apogee and perigee data are geocentric: megameters (thousands of kilometers) from center of Earth to center of Moon. Otherwise, if topocentric, this information might have seemed somewhat chaotic as the Earth's rotation causes a daily oscillation of the distance between a surface based observer and the Moon.
In the planetary tables, a morning star is a planet appearing in the sky before sunrise. An evening star is a planet seen after sunset. And a midnight star is a planet visible at local midnight (the moment midway between sunset and sunrise.) If a planet appears too close to the Sun to be easily observed, it is referred to as being lost in glare.