Mercury is behind the sun in relation to Earth and cannot be seen this month.
Brilliant Venus appears as the morning "star" during April. It's hard to miss, low in the east-southeast at dawn.
Mars reaches opposition on April 8. On that date, it's directly opposite the sun in our sky and is visible all night long. Look for it low in the east during evening twilight, high in the south at midnight, and low in the west at dawn. The bright blue-white double star Spica appears to the left of reddish Mars.
Built about 3,000 BCE, Stonehenge is one of the world’s most famous prehistoric monuments. It was constructed by a culture that left no written records but we suspect the monument’s purpose was at least partly to determine seasonal events and lunar eclipses, solstices, etc.
The Jewish calendar is mainly lunar and each month begins with the new moon. In ancient times, the Sanhedrin would wait until two trusted people witnessed the new moon before sending out messengers to inform the people that a new month had begun.
The two sides of a fragment of a circular star calendar from 720 BCE found in a library in Iraq. The inscription is in Assyrian Cuneiform with names of months, names and figures of key stars, and measurements of degrees.
This picture shows an ancient Egyptian calendar found in a temple at Karnak, near Luxor. It was one of the first really scientific calendars, with 12-month years, and 30-day months, each consisting of three 10-day weeks.
Bright Jupiter shines high in the western sky during evening twilight. Even small telescopes reveal the Jovian cloud belts and the four largest moons.
Saturn rises during the late evening hours in the southeastern sky. To the unaided eye, it appears as a bright golden "star." Even a small telescope will allow you to view the incredible ring system.
A Total Lunar Eclipse will occur in the early morning hours of April 15 and the event will be visible from North America. The moon will slowly pass completely through Earth's dark shadow (umbra), beginning at 3:06 a.m. EDT. Observers will see Earth's shadow creep across the bright moon's surface, engulfing the lunar craters and mountain ranges. For those few people still around who believe that the Earth is flat, please note that Earth's shadow on the lunar surface has a curved edge. The total phase of the eclipse will last 51 minutes.
On the night of April 22-23, the Lyrid Meteor Shower will reach its peak. This year, the waning gibbous moon will be at last quarter on that night, drowning out the fainter meteors. Try to observe from a dark site, between midnight and dawn.
TIME AND CALENDARS
"Your time is limited, so don't waste it living someone else's life."-Steve Jobs
Throughout all of recorded history, there is evidence that nearly every culture was concerned with measuring and recording the passage of time. All of the calendars that were developed over the centuries have been based on astronomical cycles. The most commonly used reference points for measuring the flow of time were the movements of the sun, moon, planets and stars across the sky. As an example, the ancient Mayans in Central America used the sun, moon and also the planet Venus to establish their calendar. Most of the world's cultures now use a 365-day solar calendar with a leap year every fourth year (except century years not evenly divisible by 400).
Essentially, this is the Gregorian calendar instituted by Pope Gregory XIII in 1582 to realign the Easter celebration with the first day of spring (vernal equinox). Pope Gregory issued a decree that established this as the new and official calendar of the entire Catholic world. Because of resistance in the Protestant regions, only five European countries immediately switched to the Gregorian calendar, although most countries now use it. Since the solar year is gradually shortening, a one-second adjustment is normally made at midnight on Dec. 31, when needed.
Besides the Gregorian calendar, many other types of calendars have been used over the years, including the:
Babylonian calendar: The Babylonian calendar was based on the lunar phases and consisted of 12 lunar months. When initially developed, days began at sunset but that was later changed to when the sun was highest in the sky. In order to make the lunar months fit the solar year, the Babylonians added leap months. However, because of the irregular insertion of random months, their calendar was very chaotic.
Coptic calendar: This is one of the oldest calendars in history and is still in use in some farming regions of Ethiopia and Egypt. The Coptic calendar consists of 12 months of 30 days each, followed by five complimentary days (six days preceding the Julian calendar leap year).
Roman calendar: The Roman calendar was devised by the first King of Rome, Romulus, in about 753 BCE. It didn't work out for too long a period because it fell out of alignment with the seasons.
Hindu calendar: The Hindu calendar, called a "panchanga," contains a lot of information, including the movements of the sun and moon. Twelve lunar months comprise the Hindu year. The calendar is consulted by devout Hindus before scheduling any type of events such as festivals, etc.
Jewish calendar: The Jewish calendar was developed by the Sanhedrin in 359 CE. It is the official calendar of Israel and is used for religious purposes by Jewish people all over the world. It is primarily based on the moon with frequent adjustments for the differences between the lunar and solar cycles. An extra month is added seven times out of every 19 years to allow the holidays to always fall in the proper seasons.
Julian calendar: Julius Caesar introduced the Julian calendar in 45 BCE in order to replace the Roman calendar. Caesar wanted a standardized calendar to be used throughout the Roman Empire and, with the astronomer Sosigenes, designed one that was based on the solar year. They designated every four years to be a leap year and, unknown to them, introduced an error of one day every 128 years.
Indian calendar: The history of calendars in India is very complex and there are many regional variations. Until the late 1950s, dozens of different calendars were used to determine the many religious festivals of the Buddhist, Hindu and Jain religions, resulting in scheduling nightmares. Finally, the government stepped in with a Calendar Reform Committee. The new calendar is based on solar positions and leap years synchronize with the Gregorian calendar.
Chinese calendar: Although the Gregorian calendar is used for civil purposes in China, the lunisolar Chinese calendar is still used to determine important dates for festivals, weddings, etc. It is an old Chinese tradition to name each calendar year after an animal, and people born during that year are supposed to show characteristics of that animal.
Islamic calendar: The starting point for the Islamic calendar is the date of Mohammed's flight from Mecca to Medina. That date is known as the Hijri and corresponds to sunset on July 16, 622 CE in the Gregorian calendar. The Islamic calendar is based solely on lunar cycles.
Egyptian calendar: The ancient Egyptians were the first to use a calendar that had 365 days in a year. It was a solar calendar but their years started when the bright star Sirius was spotted rising in the east. Julius Caesar modified the Egyptian civil calendar in about 45 BCE by adding a day every leap year. This formed the basic structure of today's Gregorian calendar, used throughout the world.
Japanese calendar: Japan developed its first calendar in the year 604 and it was based on calendars from China and Korea. For a long period of time, they were used only by the nobility. In 1873, the Gregorian calendar replaced the old lunar version
Buddhist calendar: The Buddhist calendar is lunisolar, with the years based on solar years and the months based on lunar months. Nearly all Buddhist holidays are determined by the phases of the moon rather than by dates, so the dates change every year. Tradition states that the Buddha was born in 624 BCE, attained Awakening 35 years later, and entered Nirvana (complete bliss and peace) in 544BCE at the age of 80.
There are at least 40 calendars currently in use in various regions of the world. Since 1930, a progressive group has tried to gain international approval for The World Calendar, which offers several benefits over the Gregorian calendar in use today. It would not change from year to year except for the year number. Each day would be assigned an exact, repetitive date in relation to weeks and months. There would be little need to print new calendars every year since employment, school, vacation and holiday schedules could remain static year after year. It would make our lives much simpler. However, there has been some fierce opposition to The World Calendar by religious leaders. Many refuse to change their ancient and fundamental dates of worship. Because of this, the U. S. government in 1955 decided at the U.N. not to back the proposal for the improved World Calendar.
This monthly guide to the stars is from the Marshall Martz Memorial Astronomical Association and The Post -Journal. For further information, contact the M.M.M.A.A. at www.martzobservatory.org.