Have you ever wondered at what stage you can see the new crescent moon?
The next new moon will occur on May 18th 2015 at 04:13 (GMT/UT) or 05:13 BST.
The timing of the new moon this month means that a sighting of the crescent
moon will be possible with optical aid and the naked eye on May 18th. A sighting
with optical aid may be possible from as far east as the eastern parts of the
South Atlantic Ocean, Liberia, Sierra Leone and western parts of Guinea, Guinea
Bissau, Senegal, The Gambia and the Cape Verde Islands. The earliest sighting of
the crescent moon under excellent conditions with the naked eye may be possible
the same day from as far east as central Brazil, the north-western part of South
America, the western Caribbean region and Central America. Easy sightings of the
crescent moon should be possible on May 18th from the eastern Pacific Ocean region
including the Hawaiian Islands, French Polynesia, eastern Kiribati and the Cook
Islands. The rest of the world should see the crescent moon easily the following
day, May 19th with the possible execption of north-eastern parts of Russia which
may have to wait until May 20th to make their sighting. We would therefore ask
observers to make observations of the crescent moon between May 18th and May 20th
and report them to us.
Please note: If you have subscribed to
our e-mail warning of the date of the new moon and failed to receive
any warning, particularly since November 2009, could you please let
know. A separate computer problem occurred affecting the dispatch of e-mail
warnings for May 2012 and June 2012 for which we apologise.
If you go out just after sunset over the three or four days following the
instant of new moon and have a look low in the western half of the sky
near where the Sun set, you can try and observe the new crescent moon.
You can make the observation with just your eyes or with binoculars or
a telescope. Never look at the Sun directly
or through binoculars or a telescope as you will damage your eyesight.
If you are going to use binoculars or a telescope to find the new
crescent moon, you must make sure the Sun has set.
The crescent moon will be faint shortly after new moon but will brighten
from night to night as the crescent thickens. Cloud or aircraft vapour
trails can easily be mistaken for the Moon so be careful when making the
Scan the western horizon close to where the Sun set. If you can see the
Moon, let us know by entering your observation and location in our report
form. We need to know the date and time of your observation, what the
crescent looked like, where it was in the sky relative to the position
on the horizon where the Sun set and something about the weather
conditions and you, the observer. Even if the weather is clear and you
cannot see the Moon, let us know. A negative observation will also help
Come back to this site later in the month and you can find out what you
should have seen from your observing site. You can also sign up for an
e-mail reminder of the date and time of the next new moon so you can try
your observing skills again.
Over time, we will process your observations and try to improve the models
we use to predict the first sighting of the new crescent moon. Currently,
these predictions produce a classification for a particular date and
location ranging from A (crescent easily visible) through to F (crescent
impossible to see).
For those groups who use the first sighting of the new crescent moon in
their calendars, these predictions are very significant and mark the
beginning and end of periods of fasting and festivals.
More information on these predictions is
available on this site.
This site allows observers to look at the global visibility of the
next new moon, to check their
observations of the last new moon, to
report their observations and to
receive/stop e-mail reminders of the next new
Preliminary results will also be reported on the site when they become available.
Further information on the visibility of the new crescent moon for a specific
location can be found on our Websurf
site by selecting the Moon_Viz option from the menu.
|What we want you to do|
- Go out each evening following the day of the new moon.
- Find a westerly facing spot with a clear view of the horizon.
- Wait for the Sun to set, then look for the crescent moon in that part of the sky.
- Don't look directly at the Sun, using your naked eye, binoculars or a telescope.
- Can you see the crescent moon? Are you sure? Is it a cloud or a vapour trail?
- Make a note of where you were, the date and time of your observation, the weather conditions and whether you saw the Moon or not.
- Come to this website and report your observation.
- Try and observe the crescent moon each night until you see it, reporting each observation attempt.
- Sign up for an e-mail reminder of the next new moon and come back next month and try the same thing again.