# Topband: 27 days rotation Moon & Sun

by way of Bill Tippett <btippett@alum.mit.edu> topband-bounces at contesting.com
Mon Mar 5 06:14:12 EST 2007

```Date: Mon, 5 Mar 2007 01:24:45 -0800 (PST)
From: cris blak <cyo3fff at yahoo.com>
Subject: Re: Topband: 27 days rotation Moon & Sun

Hello Thomas,

Thanks for the answer. Let me first clarify some astronomical data.

The Sun:
http://en.wikipedia.org/wiki/Sun
Rotation (around its axis) period = between 25 to 35 days; average 28 days

The Earth (Terra):
http://en.wikipedia.org/wiki/Earth
Rotation period at the equator (around its axis) = around 24 hours
Rotation period around the Sun (sidereal rotation) = around 365 days

The Moon (of the Terra):
http://en.wikipedia.org/wiki/Moon
Rotation period around the Earth (Terra) (sidereal rotation) = 27.3 days
Synodic rotation = the time between two conjunction (Moon-Sun) is
greater the the sidereal rotation of the Moon and is variable due to
several factors; is around 29.5 days
http://en.wikipedia.org/wiki/Synodic_month#Synodic_month

So, the Sun is our star and the Earth together with its moon is
rotate around it and the Moon is rotate around the Earth. Also, the
Sun, the Earth and the Moon rotate around there axis.

Having the above data we can see that the 27 to 29 days period that
we discuss about is the Moon sidereal and synodic rotation and could
be the Sun rotation too.

Now, let assume that the Sun effects on MW propagation are well known
(is not the case but...), I'm interested if some one can explain
me(or pointed to a WEB resource) what is the Moon's (Terra moon)
influence on this propagation.

Many thanks.

73 de YO3FFF
Cristi

```