Have you ever wondered why Easter is on different Sundays and not a fixed date? It has to do with the definition of the day Easter falls. Easter Sunday is defined as the first Sunday, after the first Full Moon, after the Vernal Equinox (first day of Spring). This year, the Vernal Equinox is on March 20 and the next Full Moon is on Thursday April 5. The Sunday following is April 11, and hence, Easter! This is a hybrid of the Sun and Moon based calendars. The vernal equinox can occur between March 19 and March 21. Easter is calculated based on the vernal equinox being on the 21st. If the Full Moon occurs this day and it is a Saturday, then Easter will be as early as March 22. The latest Full Moon that can occur after March 21 is April 18 and if this is a Sunday, then April can be as late as April 25.
April 2 - Venus (the bright object in the western skies) will be just south of the seven sisters (Pleiades). This is a close collection of stars that look like a little dipper.
April 4 - Daylight saving begins
April 5 - Full Moon
April 11 - Last Quarter Moon
April 11 - Easter
April 19 - New Moon
April 19 through April 25 - International Astronomy Week, with April 24 International Astronomy Day
April 23 - Mars below the Crescent Moon with Venus nearby in the western skies after sunset
April 27 - First Quarter Moon
April 29 - Jupiter just south of the Moon
The Tarleton Science Planetarium (Tarleton State University, Stephenville, Texas) has public shows every Thursday at 4:00 pm, and the first and third Saturdays at 3:45, 4:45, and 6:00 pm. You can attend all three of the Saturday shows for the price of one ticket. For more information, call 254-968-0523 or http://tarleton.edu/~planetarium.