Observations

New Moon in July 2014

A young crescent Moon. Photo Nick Lomb

A young crescent Moon. Photo Nick Lomb

The first visibility of the crescent Moon after the astronomical instant of new Moon is not only of interest to astronomers, but is of particular significance in the Islamic calendar. The crescent Moon is always first visible after sunset. For it to be visible the Moon has to have moved away from the glare of the Sun and it has to be suitably high above the horizon at sunset so that there is time for the sky to become sufficiently dark before moonset.

A number of criteria for predicting the visibility of the crescent Moon have been developed over the years.

The simplest useful criterion is the lagtime between sunset and moonset. If that time is greater than 47 minutes (at the latitude of Sydney) the crescent Moon should be visible to the unaided eye after sunset and before the setting of the Moon. This value for the time lag at Sydney’s latitude comes from the work of Mohammad Ilyas of the University of Science Malaysia (Quarterly Journal of the Royal Astronomical Society, volume 35, pages 425 to 461, 1994).

In July 2014 the Islamic month of Shawwal begins after the new Moon of 27 July. Although this occurs in the morning at 8:42 am AEST, there is no possibility of the Moon being seen that evening as in Sydney it sets only 24 minutes after the Sun.

A global map of the visibility of the Moon for 27 July is shown here. The map clearly indicates that the new Moon is not visible that day from Australia, but under perfect conditions can be seen from most of South America.

From Sydney the crescent Moon will be visible on Monday 28 July. The best time to view will be 5:47 pm when it be at azimuth 289° and altitude 7°. Its age at the time will be 33 hours 5 minutes.

Finding chart for the crescent Moon from Sydney at 5:47 pm AEST on 28 July 2014

Finding chart for the crescent Moon from Sydney at 5:47 pm AEST on 28 July 2014. Chart made with Stellarium

Anyone interested in trying to view the crescent Moon needs to find a place with a good view towards the western horizon as it will be very low in the sky. A pair of binoculars could help to locate it first in the still bright sky and only expect to see the crescent if the sky towards the west is absolutely free from clouds. Please let us know in the comments if you do manage to see the crescent Moon.

The above information is an extract from a previous post titled, The visibility of the crescent Moon from Sydney in June and July 2014. It is reposted for the convenience of readers.

14 responses to “New Moon in July 2014

  • Although it won’t be viewed at sunset set, is it possible to be seen before the Monday sunrise, if not in Australia in surrounding countries.
    Also can the moon be viewed during the moonrise on Monday

    • Hello Amz. Please have a look at the global map – link given in the post. From the map you can see that the closest country to Australia from which the crescent Moon can be seen on Sunday is South Africa. And no, the crescent Moon cannot be seen at sunrise on Monday as the first sighting of a crescent Moon is always after sunset.

  • Sallam and a very nice Good morning from Sydney Australia.
    Thank you so much for this practice research. It make so much easier for the Muslem Nation.
    Mohamed Ilyas& Nick Lomb you did very well job.
    Happy Eider for all Muslem Nation with wish and Help of GOD world wide PEACE.

    Kind Regards,

    Fari F.

  • Good clear info including the worldwide visibility map. Very helpful for Muslims in Australia and overseas. We did not just get an opinion or result but sufficient raw data. Very well written and presented. Thank you very much Nick Lomb and the staff at Sydney Observatory.

  • Dear Nick,
    Thanks a lot for reposting very useful information from the article. It seems to cause a lot of confusion almost every year with moon sighting just before Ramadan and also at the end of it to determine the specific day of the biggest Islamic festival called Eid-Ul-Fitr. I really appreciate your effort to bring it on again to give us a better understanding. I hope this trend will continue every year around Ramadan since a lot of Muslim people in Sydney will benefit from such specific information. Thanks again.

  • Hi Nick

    thanks for the very informative article.
    I just have 1 question how accurate are the moon phases calculations.

    regards
    moey

    • Hello Moey. Thanks for your comments on the blog post. The calculation of Moon phases are accurate to the nearest minute.

  • Hi Dr Nick,

    Thanks for publishing very detailed article about moon sighting. It will help wider muslim community in Australia.

    Abid

  • Hi Nick,

    I may attempt to sight the new moon this Sunday using my 14.5″ dob (location yet to be determined). I understand it will be below the revised Danjon limit at +5°30’00”, however i’m hoping that seeing is excellent at that point and my tracking spot on to be able to visually see the crescent using my Nagler.

    Regards,
    Mohammed Ali Baddah.

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