Loading...
Articles
Lunar month - Synodic month

The synodic month (συνοδικός, synodikós, meaning "pertaining to a synod, i.e., a meeting"; in this case, of the Sun and the Moon) is the average period of the Moon's orbit with respect to the line joining the Sun and Earth. This is the period of the lunar phases, because the Moon's appearance depends on the position of the Moon with respect to the Sun as seen from the Earth.

Lunar month - Draconic month

A draconic month is shorter than a sidereal month because the nodes precess in the opposite direction to that in which the Moon is orbiting Earth, one rotation every 18.6 years. Therefore, the Moon returns to the same node slightly earlier than it returns to meet the same reference star.

Lunar month - Synodic month

While the Moon is orbiting the Earth, the Earth is progressing in its orbit around the Sun. After completing a sidereal month, the Moon must move a little further to reach the new position having the same angular distance from the Sun, appearing to move with respect to the stars since the previous month. Therefore, the synodic month takes 2.2 days longer than the sidereal month. Thus, about 13.37 sidereal months, but about 12.37 synodic months, occur in a Gregorian year.

Lunar month - Anomalistic month

An anomalistic month is longer than a sidereal month because the perigee moves in the same direction as the Moon is orbiting the Earth, one revolution in nine years. Therefore, the Moon takes a little longer to return to perigee than to return to the same star.

Lunar month - Draconic month

The draconic or nodical month is the average interval between two successive transits of the Moon through the same node. Because of the torque exerted by the Sun's gravity on the angular momentum of the Earth–Moon system, the plane of the Moon's orbit gradually rotates westward, which means the nodes gradually rotate around Earth. As a result, the time it takes the Moon to return to the same node is shorter than a sidereal month, lasting 27.212220 days (27 d 5 h 5 min 35.8 s). The line of nodes of the Moon's orbit precesses 360° in about 6,798 days (18.6 years).

Lunar month - Synodic month

Since Earth's orbit around the Sun is elliptical and not circular, the speed of Earth's progression around the Sun varies during the year. Thus, the angular rate is faster nearer periapsis and slower near apoapsis. The same is so for the Moon's orbit around the Earth. Because of these variations in angular rate, the actual time between lunations may vary from about 29.18 to about 29.93 days. The long-term average duration is 29.530587981 days (29 d 12 h 44 min 2.8016 s). The synodic month is used to calculate eclipse cycles.

Lunar month - Sidereal month

The period of the Moon's orbit as defined with respect to the celestial sphere of apparently fixed stars (the International Celestial Reference Frame (ICRF)) is known as a sidereal month because it is the time it takes the Moon to return to a similar position among the stars (sidera): 27.321661 days (27 d 7 h 43 min 11.6 s). This type of month has been observed among cultures in the Middle East, India, and China in the following way: they divided the sky into 27 or 28 lunar mansions, one for each day of the month, identified by the prominent star(s) in them.

Lunar month - Anomalistic month

The Moon's orbit approximates an ellipse rather than a circle. However, the orientation (as well as the shape) of this orbit is not fixed. In particular, the position of the extreme points (the line of the apsides: perigee and apogee), rotates once (apsidal precession) in about 3,233 days (8.85 years). It takes the Moon longer to return to the same apsis because it has moved ahead during one revolution. This longer period is called the anomalistic month and has an average length of 27.554551 days (27 d 13 h 18 min 33.2 s). The apparent diameter of the Moon varies with this period, so this type has some relevance for the prediction of eclipses (see Saros), whose extent, duration, and appearance (whether total or annular) depend on the exact apparent diameter of the Moon. The apparent diameter of the full moon varies with the full moon cycle, which is the beat period of the synodic and anomalistic month, as well as the period after which the apsides point to the Sun again.

Lunar month - Draconic month

A draconic month or draconitic month is also known as a nodal month or nodical month. The name draconic refers to a mythical dragon, said to live in the lunar nodes and eat the Sun or Moon during an eclipse. A solar or lunar eclipse is possible only when the Moon is at or near either of the two points where its orbit crosses the ecliptic plane; i.e., the satellite is at or near either of its orbital nodes.

Month - Beginning of the lunar month

The Hellenic calendars, the Hebrew Lunisolar calendar and the Islamic Lunar calendar started the month with the first appearance of the thin crescent of the new moon.

Month - Beginning of the lunar month

Pingelapese, a language from Micronesia, also uses a lunar calendar. There are 12 months associated with their calendar. The moon first appears in March, they name this month Kahlek. This system has been used for hundreds of years and throughout many generations. This calendar is cyclical and relies on the position and shape of the moon.

Iunius (month) - Name of the month

In his poem on the Roman calendar, Ovid has three goddesses present three different derivations of the name Iunius. Juno asserts that the month is named for her. Juventas ("Youth") pairs Iunius with Maius: the former, she says, comes from junior, "a younger person", in contrast to maiores or the "elders" for whom May was named. Juno's own name may derive from the same root meaning "young", and these two possibilities may be reconcilable. Ovid has Concordia claim that Iunius comes from iungo, iunctus, "join", in honor of her uniting the Romans and the Sabines. Elsewhere, an even less likely derivation relates the month name to Marcus Iunius Brutus, a member of the gens Iunia who made the first sacrifice to Dea Carna on the Kalends (June 1).

Women's History Month - Women's History Month

In 1987, after being petitioned by the National Women's History Project, Congress passed [http://www.gpo.gov/fdsys/pkg/STATUTE-101/pdf/STATUTE-101-Pg99.pdf Pub. L. 100-9] which designated the month of March 1987 as Women's History Month. Between 1988 and 1994, Congress passed additional resolutions requesting and authorizing the President to proclaim March of each year as Women's History Month. Since 1988, U.S. presidents have issued annual proclamations designating the month of March as Women's History Month.

Women's History Month - Women's History Month

State departments of education also began to encourage celebrations of Women's History Month as a way to promote equality among the sexes in the classroom. Maryland, Pennsylvania, Alaska, New York, Oregon, and other states developed and distributed curriculum materials in all of their public schools, which prompted educational events such as essay contests. Within a few years, thousands of schools and communities began to celebrate of Women's History Month. They planned engaging and stimulating programs about women's roles in history and society, with support and encouragement from governors, city councils, school boards, and the U.S. Congress.

National Preparedness Month - National Preparedness Month Coalition

An organization can become a National Preparedness Month Coalition Member by agreeing to participate in a preparedness activity or event in the month of September. National Preparedness Month Coalition members have agreed to promote emergency preparedness through a variety of different ways. Members can sponsor events, coordinate Disaster Preparedness Days, create Disaster Checklists, assist with the creation of emergency kits and survival kits, along with many other Preparedness activities.

National Safety Month - National Safety Month 2018

The theme for National Safety Month in June 2018 is " No 1 Gets Hurt. " Each week in June correlates with a different safety topic:

September (Roman month) - Iconography of the month

In calendar mosaics from Hellín in Roman Spain and Trier in Gallia Belgica, September is represented by the god Vulcan, the tutelary deity of the month in the menologia rustica, depicted as an old man holding tongs. The mosaic from Hellín (2nd–3rd century) depicts each of the months as a personification with or representing a zodiac sign. September is shown holding balance scales and assisted by Vulcan. The scales represent Libra, the astrological sign entered late in the month. In the Laus omnium mensium ("Praise of All the Months"), a poem dating to the early 6th century, September "divides the hours equally for Libra".

September (Roman month) - Iconography of the month

In an ancient Christian mosaic from Gerasa in the province of Arabia (present-day Jordan), September has the typical attributes of a vintager in Roman art—a young man wearing a tunic and chlamys carries a bunch of grapes in his right hand and has a basket on his shoulder—but is labeled as Gorpiaios, the first month of the year in the local calendar, equivalent to the period August 19 to September 17.

National Safety Month - National Safety Month 2017

The theme for National Safety Month in June 2017 was "Keep Each Other Safe," which underscored the role every individual plays in the effort to eliminate preventable deaths. Each week in June correlated with a different safety topic:

Financial Literacy Month - Financial Literacy Month in Canada

The purpose of this month is to educate the public so Canadians are equipped to:

Loading...