- Posts: 3298
- Thank you received: 57
Blue Moon??
- Frank Ryan
- Offline
- Super Giant
Less
More
14 years 11 months ago #82899
by Frank Ryan
My Astrophotography
Shannonside Astronomy Club __________________________________________
Meade ETX-125PE, Bresser 10 x 50 Binos & Me Peepers
Replied by Frank Ryan on topic Re:Blue Moon??
S&T may have retracted it but they are happy to live with
it now.
check thier website for the story.
it now.
check thier website for the story.
My Astrophotography
Shannonside Astronomy Club __________________________________________
Meade ETX-125PE, Bresser 10 x 50 Binos & Me Peepers
Please Log in or Create an account to join the conversation.
- Seanie_Morris
- Offline
- Administrator
Less
More
- Posts: 9640
- Thank you received: 547
14 years 11 months ago - 14 years 11 months ago #82918
by Seanie_Morris
Midlands Astronomy Club.
Radio Presenter (Midlands 103), Space Enthusiast, Astronomy Outreach Co-ordinator.
Former IFAS Chairperson and Secretary.
Replied by Seanie_Morris on topic Re:Blue Moon??
2 Full Moons in any one calendar month is my understanding too. Once every 2.7 years.
Seanie.
Seanie.
Midlands Astronomy Club.
Radio Presenter (Midlands 103), Space Enthusiast, Astronomy Outreach Co-ordinator.
Former IFAS Chairperson and Secretary.
Last edit: 14 years 11 months ago by Seanie_Morris.
Please Log in or Create an account to join the conversation.
- dmcdona
- Offline
- Administrator
Less
More
- Posts: 4557
- Thank you received: 76
14 years 11 months ago #82922
by dmcdona
Replied by dmcdona on topic Re:Blue Moon??
I recall doing a radio interview and I looked up all the various definitions. For the sake of an easy explaination I plumped for the "two full moons in the same calendar month" as published by S&T.
Another reference (possibly the same one) also referred to the case where there are two such instances in the same calendar year - it is the second instance that is called the "blue" moon.
Also, I found some data that suggested this happens every two to three years.
Another reference (possibly the same one) also referred to the case where there are two such instances in the same calendar year - it is the second instance that is called the "blue" moon.
Also, I found some data that suggested this happens every two to three years.
Please Log in or Create an account to join the conversation.
- ayiomamitis
- Offline
- Super Giant
Less
More
- Posts: 2267
- Thank you received: 7
14 years 11 months ago #82926
by ayiomamitis
Anthony Ayiomamitis
Athens, Greece
www.perseus.gr
Replied by ayiomamitis on topic Re:Blue Moon??
Dave,
There was an interesting graphic the other day which had year on the vertical axis (ex. 2000, 2001, etc) and month on the horizontal axis with a small circle depicting months with two full moons.
You would be surprised how often they happen. The reference above to 2.7 yrs seems quite accurate and, in fact, on the basis of my memory of the graphic, I would not be surprised if it is even more often than once every 2.7 yrs.
Anthony.
There was an interesting graphic the other day which had year on the vertical axis (ex. 2000, 2001, etc) and month on the horizontal axis with a small circle depicting months with two full moons.
You would be surprised how often they happen. The reference above to 2.7 yrs seems quite accurate and, in fact, on the basis of my memory of the graphic, I would not be surprised if it is even more often than once every 2.7 yrs.
Anthony.
Anthony Ayiomamitis
Athens, Greece
www.perseus.gr
Please Log in or Create an account to join the conversation.
- ayiomamitis
- Offline
- Super Giant
Less
More
- Posts: 2267
- Thank you received: 7
14 years 11 months ago #82927
by ayiomamitis
Anthony Ayiomamitis
Athens, Greece
www.perseus.gr
Replied by ayiomamitis on topic Re:Blue Moon??
PS. This graphic is similar to the one I had seen the other day also on the S&T website:
www.skyandtelescope.com/observing/object...5141.html?page=2&c=y
... and indeed the 2.7 yr average seems dead on.
Anthony Ayiomamitis
Athens, Greece
www.perseus.gr
Please Log in or Create an account to join the conversation.
- mjc
- Offline
- Main Sequence
Less
More
- Posts: 470
- Thank you received: 20
14 years 11 months ago #82929
by mjc
Replied by mjc on topic Re:Blue Moon??
Taking calculations to three decimal places
Synodic period of moon (time from full moon to full moon) = 29.531 days.
Earth year 365.243 days.
Number of synodic periods in one year = 365.243 / 29.531 = 12.368
That is twelve with a bit over.
How long does it take for those bits to round over into a whole number (an extra full moon)
We take the remainder 0.368 and take the reciprical ( divide it into one)
1/0.368 = 2.716 years
Any excuse to use my calculator...
Mark
Synodic period of moon (time from full moon to full moon) = 29.531 days.
Earth year 365.243 days.
Number of synodic periods in one year = 365.243 / 29.531 = 12.368
That is twelve with a bit over.
How long does it take for those bits to round over into a whole number (an extra full moon)
We take the remainder 0.368 and take the reciprical ( divide it into one)
1/0.368 = 2.716 years
Any excuse to use my calculator...
Mark
Please Log in or Create an account to join the conversation.
Moderators: Neill
Time to create page: 0.112 seconds