Phases of moon determine holidays

BY Carol Lutsinger is a NASA/JPL Solar System educator and ambassador Texas Space Grant Consortium collaborator and American Astronomical Society resource agent carolutsinger@att.net Newspaper in Education

Monday the 8th was the New Moon so as the week progresses it will be at First Quarter Moon phase next Monday, Full Moon on the 22nd, Last Quarter March 2, and New again on March 8th. The phases of the Moon determine when the Christian world commemorates Easter and the Jewish world commemorates the Feast of the Passover. Many ancient cultures based most of their ceremonies on the lunar phases which we continue to this day. The details as to why are too complicated to go into here but there are several sites online that will give you some great details regarding our historical celebrations. One is http://christianity.about.com/ or just use Google and explore other points of view.

The evening sky’s first star is Sirius, the Dog Star. It appears to be the brightest star in the night sky and is the one to which all other stars are compared. It has unique status in that it is the only star that can be seen with the naked eye from North America and Europe by most observers and the nearest star neighbor other than the sun. Sirius is almost 9 light years away (53 trillion miles). If the sun were the size of a Ping Pong ball, the earth would be a pinprick 13 feet away and Sirius would be a tennis ball 1400 miles away, or to put it in context another way the distance from the Valley to Costa Rica or Montana. If that doesn’t boggle your brain, I will try to accomplish that another way.

The exploring twin Voyager spacecrafts that were the first spacecraft to fly by the planets were launched in 1977. They have been travelling through space since then. Voyager 1 entered interstellar space three years ago. Travelling at 50,000 mph it would take it more than one hundred thousand years. Current plans are for Voyager 1 to fly by a star designated AC+793888, which is 17.6 lightyears from earth and will take 40,000 years traveling at its current rate.

Many ancient cultures assigned a wolf or dog figure to the stars in Canis Major where Sirius is to be found. I like to say the star is the rabies tag because the owner cared about ensuring good health for his pet, reminding audiences how important those are to us here in the Rio Grande Valley. Rabies is a constant menace.

Sirius also signified time for the Nile to flood. Farmers get ready to plow and plant so there is a bountiful harvest. Ancient Egyptians worshiped this star because it rose just before dawn on the first day of summer. Several Egyptian temples were oriented so that the light from that rising star shone into the dark interiors.

Other cultures also understood astronomy well enough to arrange this event with other stars, including our sun. An entirely new type of astronomy has developed over the past thirty years called archeoastronomy that has led to an abundance of theories about just how advanced those ancient cultures actually were. It is a fascinating topic, at least to me.

Wake up and go out before sunrise to be treated to the spectacular view of 5 planets in the eastern sky. In order of placement, Mercury near the eastern horizon until midmonth, Venus visible at dawn, Mars rises after midnight, Saturn rises in the early morning, and Jupiter rises after midnight.

Until next week, KLU.