Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 29/07/2007 16:19:42

Title: How long are a day and a year on the Moon?
Post by: neilep on 29/07/2007 16:19:42

How long is an official Moon day ?...24 hours ?....what about a  Moon year ?.....same as earth  ? or is it the time it takes to circulate the earth ?...about a month ?

I'm not a lunartic !!..

Title: Re: How long are a day and a year on the Moon?
Post by: syhprum on 29/07/2007 20:11:24

The Moon rotates relative to the Sun once in 28 earth days hence that is the length of a Moon day.
As the Moon stays close to the Earth its year is of the same length as that of the Earth.

Title: Re: How long are a day and a year on the Moon?
Post by: neilep on 29/07/2007 20:46:02

THANK YOU SYHPRUM...very much indeed !!

Title: Re: How long are a day and a year on the Moon?
Post by: chris on 15/08/2017 08:57:23

This one from a decade ago really got me thinking!

Title: Re: How long are a day and a year on the Moon?
Post by: evan_au on 15/08/2017 11:46:20

Some cultures use a lunar calendar (https://en.wikipedia.org/wiki/Lunar_calendar), eg counted from the first sighting of the new moon. That gives a Lunar month of 29 or 30 days, as the moon cycles through its phases from new moon to new moon.

If you judged a month on the Moon (a lunar month) as the time it takes the Earth to cycle through its phases from New Earth through Full Earth and back to New Earth, you would end up with pretty much the same as a Lunar Day (and the same as a Lunar Month on Earth).
 

...That is, if you are on the half of the Moon that can see the Earth continuously.