When is Ramadan in 2010?

By Drs Henry Woodruff and Andrew Jacob,
Acting Curators

The calendar we use in civil society (the ‘Gregorian’ calendar) is a solar one – based on the time it takes for the Earth to orbit the Sun. Many religious calendars, however, are based on the phases of the Moon. These include the Catholic, Jewish and Islamic religious calendars. The dates of festivities, holidays and important events in the lunar calendar move by about 10 days every year within the Gregorian calendar.

The ninth month of the Islamic calendar, known as Ramadan, is the Islamic month of fasting. The Hilal, or crescent Moon, marks the beginning of the fasting period. However, there are differences of opinion on how to define ‘crescent’. While some simply demand an unaided sighting by eye of the crescent moon, others are leaning towards using astronomical calculations to avoid confusion.

The following astronomical data concern the new moons in August and September of 2010.

The new moon in question will happen at 1:08 pm on Tuesday, August 10th (all times AEST, i.e. Sydney time). On that day the Sun will set at 5:22pm, and the Moon at 5:34pm, giving an elongation (angular separation in the sky) of only 3 degrees. This is not likely to be enough for the crescent Moon to be visible. On Wednesday, August 11th, the Sun will set at 5:22pm and the Moon at 6:47pm, with an elongation of 21 degrees. In this case the crescent Moon should be visible if the western sky is cloud free. The following new moon (marking the end of Ramadan and thus the beginning of Eid-ul-Fitr) occurs on Wednesday, September 8th at 8:30pm – after sunset. On Thursday the 9th the Sun sets at 5:42pm and the Moon sets at 6:45pm with a 15.75 degree elongation. If the crescent Moon is not visible on this night it should be visible the following night.

Ramadan Mubarak!

14 Responses to “When is Ramadan in 2010?”

  1. Siddiq Buckley  on July 31st, 2010

    Thanks Andrew, for the relevant information.
    It’s great to have the local astronomers providing us with our own data.
    Much appreciated.
    Ramadan Mubarak to you too!

  2. Muhammad Khodr  on August 8th, 2010

    Wow, this succint article is brilliant! I would love to see such an article every year! :)

    I second your comment brother Siddiq, what a thoughtful and useful piece of information indeed.

    I am extra glad that the information I have compiled on the topic myself has been confirmed by experts. Hooray for Drs Henry Woodruff and Andrew Jacob!

    And Hooray for Ramadan!

  3. Jabed Chowdhury  on August 10th, 2010

    This so great to see topic on Ramadan moon sighting from Astronomers.

    Thanks a lot Andrew and Henry.

    Happy Ramadan greetings.

  4. TH  on August 10th, 2010

    Thanks for an excellent article!! Will really help us in planning our fasting schedule.

    Could you please do this every year?? Thanks again!

  5. Mohammad Adil Khan  on August 10th, 2010

    Dear
    Drs Henry Woodruff and Andrew Jacob,

    A lot of thanks for clearing the confusion of when should we start fasting.
    I am really gratful.
    Ramzan Mubarak to you too
    and also
    Eid Mubarak
    Hope you can do that next year too

  6. BASCONAS  on August 10th, 2010

    GREAT ARTICLE MAY ALLAH REWARD YOU BOTH.

  7. Rhythm  on August 11th, 2010

    Awesome. A report like this needs to be done every lunar month. You have the credibility, and I guess a really big telescope at hand helps too. :)

    Photos of the crescent moon would be a big plus.

  8. Sam Allen  on August 11th, 2010

    Thanks you for the interesting insight :)

  9. faisal  on August 11th, 2010

    Thanks hips to Drs Henry Woodruff and Andrew Jacob for the awesome report, I will highly appreciate if you would do this every year to clear the confussion among Muslims in Australia.

    May Allah reward you both for this article and finally Ramadan Kareem to all brothers and sisters in islam.

    Faisal

  10. mm.hassan@gmail.com  on August 11th, 2010

    Thanks a lot to the Observatory Team for such an insightful input to our community.

  11. akbar  on August 12th, 2010

    Thank you for this very informative and concise piece. Would it be possible for you to give similar information for Fiji?

  12. Said Jamal  on August 12th, 2010

    Thank you for this information. I suggest that the Sydney observatory work with Australian National Crescent Sighting Coordination Centre (http://crescentwatch-australia.alghazzali.org). It has many imams working together and headed by imam Afroze Ali who has lectureed about the islamic law and science of the crescent. Their work provides exactly this kind of information every month and also sighting guides for the key months. All muslims should use that.

  13. sunshine  on August 29th, 2010

    hello. i’m a bit delayed…Ramadan is almost done right.I happened to cross ur article and i think the stuff u astronomers do is awesome…absolutley mind boggling,mind blasting and just want to tell u to keep up all the cool things u do…
    I ask the Almighty power,Designer of The Universe,Sustainer,Originater to increase us with beneficial knowledge about our universe so we can live in harmony with itand others.

  14. Wahid  on September 9th, 2010

    Thanks to the good Drs for the insightful article. Id take your word on the new moon any day.
    Some food for thought in regards to the start and finish of Ramadan: The Prohetic tradition ( Hadith) says. ” We are a nation who can not count so start your fast when you sight the crescent and break your fast when you sight it again”. The nation being referred to was the early Islamic community in Arabia as of course muslims later went on to be master mathematicians and astronomers. As God has now made Drs Woodruff & jacob available (along with thier telescopes), it is more logical that “new moon” should signal the start and finish of the month.


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