Karaite Korner Newsletter #474

When is Yom Teruah?

Next week is the biblical festival of Yom Teruah, the Day of Shouting/ Trumpeting (literally: noise-making). The moon will definitely be visible from Israel on Friday night September 10, so the question is whether it will also be visible Thursday night. The answer is yes and no. Yes it will be visible Thursday night, but no, not from the Land of Israel. Let me explain. Thursday night the moon will have 2.5% illumination over Jerusalem and normally that should make it easy to sight. But the lagtime - the time between sunset and moonset - will only be 23 minutes. This short lagtime means that the moon will set before the light of the sun fades, making it impossible to see the moon. As you travel south the lagtime will increase, so in the southern hemisphere and even in some parts of the northern hemisphere it will be easy to see but not in Israel. I will be traveling down to Eilat where the lagtime will increase to 26 minutes. Previous experience indicates that 26 minutes will not be enough to sight the moon, although I will attempt to do so. I will be sending out a report late Thursday when I return from Eilat, but it's a 4.5 hour drive to Jerusalem so that probably won't be until well after midnight. I will, however, tweet the results from the road and you can check that out at:
http://twitter.com/ngordon4

For more information about Yom Teruah please see:
http://www.karaite-korner.org/yom_teruah.shtml

Nehemia Gordon
Jerusalem, Israel