The Moon waxes and wanes for us all
![[NASA] Moon and Earth composite view from 4 million miles.](2001-06-13-east-sky.jpg) Q: Are the phases of the moon the same all over the world, east and west, north and south, at the same time,
or they are different ? --Marilia S., Victoria ES, Brazil
A: The phases of the Moon are the same all over the world at the same time but we may not be able to see the
Moon everywhere at the same time.
[NASA] Moon and Earth composite view from 4 million miles.
For example, we can't see the Full Moon everywhere because the Earth itself is in the way for people on the dayside of Earth. Suppose
I live in Camooweal, Australia-on the other side of Earth from you in Victoria, Brazil. The Moon is opposite the Earth when it is full.
At the night of the next full moon (January 29 in Victoria), you, in Victoria, will see the full Moon but, I, in Camooweal, can't at the
same time. I need X-ray vision to see through Earth to view the full Moon when you see it. However, I can wait a few hours until it's
dark in Camooweal and see the full Moon although it will have moved slightly in its orbit by then and my view will be a bit different-the
Moon being somewhat less than full.
On January 19, though, we can both see a waxing crescent moon (about 30 % of the Moon's visible disk illuminated) from different
sides of Earth. We have to pick our times. Stay up until 11:30 p.m. by your watch and look out the window to the west. You will see
the crescent Moon just above the horizon setting. At the same time, when it's 11:30 a.m. by my watch in Camooweal, Australia-I'll
step outside and look to the east to see the crescent Moon just above my horizon, rising to the east. We both see the exact same thing: a
waxing crescent Moon, about 30 % illuminated.
Whether you can see the Moon from any two places in the world at once depends also on how far north or south the Moon is, says
Robert Massey of the Royal Observatory Greenwich in London.
(Answered by April Holladay, science correspondent, January 16, 2002)
Further Surfing:
USATODAY.com, WonderQuest: Seeing the daytime Moon
USATODAY.com, WonderQuest: Understanding the phases of the Moon
USATODAY.com: Sun, moon, starts, time resources
Royal Observatory Greenwich: The Moon
U.S. Naval Observatory: Moon and Sun data
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