It’s A Super Perigee New Moon – But Don’t Look!

   Our Moon reaches perigee, (closest to Earth), for this orbit, on Friday October 16th. At that time the new Moon, in the direction of the Sun, will be at a distance of 27.98 Earth diameters, or 221,767 miles (356,900 km) from the Earth, and about 7-10 km further than the super perigee Moon of this past April.
   At this distance the new Moon is at its second closest perigee distance allowing this new Moon to be considered a ‘Super Moon’.
   Don’t look for the Moon as it is at new phase and in the direction of the Sun. Stay safe and explore the Super Moons for 2020 graphically.

   Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*
   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

I Caved! My Super Moon Pictures

   How could I resist. I parked at my favorite light polluted photo spot – a dirt field alongside a 2-lane access road parallel to the 4-lane 50 Highway. With Car Dealerships lining the access road on the opposite side of 50 Highway.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

November Perigee, and Full Moon

14nov-perigee_moon   The Moon reaches perigee, (minimum distance from Earth), this month on Monday November 14th. At that time the Moon will more or less be at a distance of 27.95 Earth diameters (356,509 km or 221,524 miles) from the Earth.
   The Moon reaches perigee Monday at 11:30 UT (5:30 am CST) and this is about 2 hours before it will be at full Moon phase at 13:52 UT, (7:52 am CST November 14th). Since the full Moon is this close to its closest to the Earth for this orbit the full Moon could be considered one of the ‘Super Moons’ this year. In fact this is the closest one for this year and according to records the closest full Moon in the past 30 years.
full-moons2016-ani
   This animated graphic shows the full Moons of 2016. Are you able to see a difference in the sizes?

   Read more about the idea of a super Moon or super mini-Moon in a previous posting.

   Does our Moon actually go around the Earth as the first graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth.
   Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)
   Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   On the day of the lunar perigee the full Moon rises at around sunset local time and is setting at sunrise the following morning.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

Super Moon 3-2=1

 Graphic Credit: Heart Touching Fun (red-lined by me)

Graphic Credit: Heart Touching Fun (dates red-lined by me)

   File this under the ‘here we go again’ once again, again. Three “Super Moon” ‘events’ in a row starting with the full Moon of this past July 12th; then again on August 10th; and then again with this one on September 9th. I am hoping that this graphic will help in putting my thoughts into context. Meaning exactly how big is a Super Moon compared with other full Moons, and will it really be noticeably larger?
   According to this graphic which was on Facebook about a year ago the full Moon of 23 June 2013 would be the largest appearing one of that year as well as the closest one for that year – a “Super Moon”. While the part about closest and largest appearing is correct, using the term “Super Moon” is misleading in the sense that there is nothing for comparison and so there will be folks going outside expecting to see a really large appearing full Moon? But how large? As large as the banner graphic suggests!!
sci-ence_neiltyson_moonillusion   So what is a “Super Moon”; how “super” is it in comparison to other full Moons. And how significant, if at all, is this ‘event’?
   A “Super Moon” is a full Moon that occurs very near to its time of perigee, the closest the Moon comes to the Earth for that particular orbit, or month. By definition, “very close” would be when the Moon is less than 10% of its orbital period (about 2.9 days to 3.2 days) from the time of perigee. Use the data in the table below to compare the full and new Moon dates, with the apogee (farthest) and perigee dates and distances. Dates for apogee and perigee are given showing how many days and or hours before or after the date of the new or full moon these two distances occur.
   Here is an idea – use the apogee dates to determine when we will have a “Super Mini-Moon”!

This slideshow requires JavaScript.


   By comparing the dates and distances for this year, you will see that there are several “Super Moon”s in 2014. In fact, each year there are from four to six occurrences when the full Moon and perigee are close enough to be considered a “Super Moon” – the full Moon closest to the time for perigee is the actual “Super Moon” for that year. So a “Super Moon” is not that unique nor worthy of the hype these next three will receive other than drawing people’s attention to the night skies and our closest natural solar system neighbor.
   Carry this analysis further by comparing dates for full Moon and perigee over a several year period, and you’ll find a pattern in the regularity of “Super Moon” events. How? There are two regular time periods, or cycles, involved in the pattern for “Super Moon”. First, the time period between each full Moon, the synodic month, is approximately 29.53 days; second, the time period between each perigee, the anomalistic month, is approximately 27.55 days. With a two-day difference between these two cycles, there is obviously not a super Moon every month. However, with a ratio of 14 synodic months to 15 perigee periods,the closest of the “Super Moons” to perigee will occur about every 13-14 months. Because of the ratio relationship between these two cycles, 14 full Moons after the full Moon of June 23, 2013 (356,989 km), there will be the closest full Moon of 2014 on August 10th (356,896 km), which will be followed by the closest full Moon of September 28, 2015 (356,877 km), and so on.

   The above has been adapted from my October 2012 Scope on the Skies column in Science Scope Magazine “Apparent Sizes, or It Was This Big”. Click here to download a copy of that column (PDF).

   Before you look at the data tables below here are some ‘Super Moon’ pictures and graphics I collected from around the web. Since most of the pictures are of a rising or setting Moon and there are objects in the foreground this creates an optical illusion where the Moon appears to be quite large. I think that folks see the Moon as in these pictures and are convinced that they have indeed seen a ‘Super Moon’ – when in fact they have not.
Prove the Moon Does Not Change Its Size:
   To help correct this idea or to prove to yourself that the Moon is not bigger when it rises or sets look at the Moon through a toilet paper tube or something similar when the Moon is near the horizon and then a couple of hours later when it is higher above the horizon. The Moon is same size on both sightings.

This slideshow requires JavaScript.

             
 (N=New Moon; F=Full Moon '-' = before; '+' = after)
           2014 - All times are shown in UT (Universal Time)
             Perigee                            Apogee
---------------------------------   ---------------------------------
Jan  1 21:01 356921 km -  N+   9h   Jan 16  1:54 406536 km +  F-   2h
Jan 30  9:59 357079 km -  N-  11h   Feb 12  5:11 406231 km +  F-2d18h
Feb 27 19:53 360438 km    N-1d12h   Mar 11 19:47 405365 km    F-4d21h
Mar 27 18:31 365705 km    N-3d 0h   Apr  8 14:53 404501 km    F-6d16h
Apr 23  0:28 369764 km    N-6d 5h   May  6 10:23 404318 km    N+7d 4h
May 18 11:59 367098 km    F+3d16h   Jun  3  4:26 404955 km    N+5d 9h
Jun 15  3:35 362061 km    F+1d23h   Jun 30 19:11 405931 km    N+3d10h
Jul 13  8:28 358258 km    F+  21h    Jul 28  3:28 406568 km -- N+1d 4h
Aug 10 17:44 356896 km ++ F-   0h   Aug 24  6:10 406522 km -  N-1d 8h
Sep  8  3:30 358387 km    F-  22h   Sep 20 14:23 405845 km    N-3d15h
Oct  6  9:42 362480 km    F-2d 1h   Oct 18  6:06 404897 km    N-5d15h
Nov  3  0:22 367870 km    F-3d22h   Nov 15  1:57 404336 km    N-7d10h
Nov 27 23:12 369824 km    N+5d10h   Dec 12 23:04 404583 km    F+6d10h
Dec 24 16:44 364790 km    N+2d15h   

Data Table Source: Lunar Perigee and Apogee Calculator. http://www.fourmilab.ch/earthview/pacalc.html
   

2014 Lunar Phases — Using U.S.A. Central Time (UT-6 or UT-5) 
      New Moon	           Full Moon	            
Jan. 1 We. 05:15 AM	Jan. 15 We. 10:53 PM	
Jan. 30 Th. 03:40 PM	Feb. 14 Fr. 05:54 PM	
Mar. 1 Sa. 02:02 AM	Mar. 16 Su. 12:10 PM	
Mar. 30 Su. 01:48 PM	Apr. 15 Tu. 02:45 AM	
Apr. 29 Tu. 01:17 AM	May 14 We. 02:18 PM	
May 28 We. 01:43 PM	June 12 Th. 11:13 PM	
June 27 Fr. 03:10 AM	July 12 Sa. 06:26 AM	
July 26 Sa. 05:42 PM	Aug. 10 Su. 01:10 PM	
Aug. 25 Mo. 09:13 AM	Sept. 8 Mo. 08:38 PM	
Sept. 24 We. 01:13 AM	Oct. 8 We. 05:50 AM	
Oct. 23 Th. 04:56 PM	Nov. 6 Th. 04:22 PM	
Nov. 22 Sa. 06:32 AM	Dec. 6 Sa. 06:27 AM	
Dec. 21 Su. 07:36 PM			    

Source of Lunar Phase Data: Moon Phases.

   
   
   
[centup]
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

How Super Is It?

   Here is an idea to prove that the Moon Does Not Change Its Size:moon-size-ani

    Assuming you have clear skies this evening as the full Moon rises the Moon probably will be observed by many as a Super Moon. But even without knowing this have you ever noticed how large the full Moon appears to be as it rises? This large appearing Moon is especially noticeable when, for example, there are trees along your local viewing horizon and the Moon is behind the trees as it rises. This is an optical illusion and while very convincing in appearance it is an illusion that is easily seen as just that – an illusion.
   To help correct this idea or to prove to yourself that the Moon is not bigger when it rises or sets look at the Moon through a toilet paper tube or something similar when the Moon is near the horizon, and then a couple of hours later when it is higher above the horizon. As this animated graphic illustrates the Moon is not only the same apparent size on both sightings, it is the same apparent size throughout the night, even as it sets.
Just the Facts:
Full Moon rise at local sunset time – Full Moon set at local sunrise time.
Full Moon will be 13% – 14% larger then the other full Moons of 2014.
Should be brighter when compared with…(presumably other full Moons that one has observed and recorded the apparent brightness to be used as a future reference for comparing with a Super Moon).

Go to the NASA web site for more about this picture and to see it full size.

Go to the NASA web site for more about this picture and to see it full size.

But without anything for comparison, and/or without any media hype, would you know this is a Super Moon?

   
   
   
[centup]
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

August Perigee Moon Is the Super Moon for this Year

10aug-perigee-moon    Our Moon orbits around the Sun with the Earth and from our perspective on the Earth the Moon appears to circle around the Earth, however in reality the Moon orbits the Sun together with the Earth*.
   The 14.8 day old waxing gibbous Moon reaches perigee this month on Sunday 10 August at 17:48 UT (12:48 pm CDT). At that time the Moon will more or less be at a distance of 27.98 Earth diameters (356,542 km or 221,545 miles) from the Earth. This is the closest that the Moon will come to the Earth during 2014. What makes this one sort of unique is that full Moon occurs 22 minutes later at 18:10 UT (1:10 pm CDT). This full Moon is the Super Moon of the Year.

   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Click on graphic to see it full size.

Click on graphic to see it full size.

 
  Sunday evening the full Moon rises shortly after sunset local time.

   
   
   
   
   
   
   
   
[centup]
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Super Moon 3-1=2

 Graphic Credit: Heart Touching Fun (red-lined by me)

Graphic Credit: Heart Touching Fun (dates red-lined by me)

   File this under the ‘here we go again’ once again. Three “Super Moon” ‘events’ in a row starting with the full Moon of this past July 12th; now this one on August 10th; and then again on September 9th. I am hoping that this graphic will help in putting this into context. Meaning exactly how big is a Super Moon compared with other full Moons, and will it really be noticeably larger?
   According to this graphic which was on Facebook about a year ago the full Moon of 23 June 2013 would be the largest appearing one of that year as well as the closest one for that year – a “Super Moon”. While the part about closest and largest appearing is correct, using the term “Super Moon” is misleading in the sense that there is nothing for comparison and so there will be folks going outside expecting to see a really large appearing full Moon? But how large? As large as the banner graphic suggests!!
   So what is a “Super Moon”; how “super” is it in comparison to other full Moons. And how significant, if at all, is this ‘event’?
   A “Super Moon” is a full Moon that occurs very near to its time of perigee, the closest the Moon comes to the Earth for that particular orbit, or month. By definition, “very close” would be when the Moon is less than 10% of its orbital period (about 2.9 days to 3.2 days) from the time of perigee. Use the data in the table below to compare the full and new Moon dates, with the apogee (farthest) and perigee dates and distances. Dates for apogee and perigee are given showing how many days and or hours before or after the date of the new or full moon these two distances occur.
   Here is an idea – use the apogee dates to determine when we will have a “Super Mini-Moon”!

This slideshow requires JavaScript.


   By comparing the dates and distances for this year, you will see that there are several “Super Moon”s in 2014. In fact, each year there are from four to six occurrences when the full Moon and perigee are close enough to be considered a “Super Moon” – the full Moon closest to the time for perigee is the actual “Super Moon” for that year. So a “Super Moon” is not that unique nor worthy of the hype these next three will receive other than drawing people’s attention to the night skies and our closest natural solar system neighbor.
   Carry this analysis further by comparing dates for full Moon and perigee over a several year period, and you’ll find a pattern in the regularity of “Super Moon” events. How? There are two regular time periods, or cycles, involved in the pattern for “Super Moon”. First, the time period between each full Moon, the synodic month, is approximately 29.53 days; second, the time period between each perigee, the anomalistic month, is approximately 27.55 days. With a two-day difference between these two cycles, there is obviously not a super Moon every month. However, with a ratio of 14 synodic months to 15 perigee periods,the closest of the “Super Moons” to perigee will occur about every 13-14 months. Because of the ratio relationship between these two cycles, 14 full Moons after the full Moon of June 23, 2013 (356,989 km), there will be the closest full Moon of 2014 on August 10th (356,896 km), which will be followed by the closest full Moon of September 28, 2015 (356,877 km), and so on.

   The above has been adapted from my October 2012 Scope on the Skies column in Science Scope Magazine “Apparent Sizes, or It Was This Big”. Click here to download a copy of that column (PDF).

   Before you look at the data tables below here are some ‘Super Moon’ pictures and graphics I collected from around the web. Since most of the pictures are of a rising or setting Moon and there are objects in the foreground this creates an optical illusion where the Moon appears to be quite large. I think that folks see the Moon as in these pictures and are convinced that they have indeed seen a ‘Super Moon’ – when in fact they have not.
Prove the Moon Does Not Change Its Size:
   To help correct this idea or to prove to yourself that the Moon is not bigger when it rises or sets look at the Moon through a toilet paper tube or something similar when the Moon is near the horizon and then a couple of hours later when it is higher above the horizon. The Moon is same size on both sightings.

This slideshow requires JavaScript.

             
 (N=New Moon; F=Full Moon '-' = before; '+' = after)
           2014 - All times are shown in UT (Universal Time)
             Perigee                            Apogee
---------------------------------   ---------------------------------
Jan  1 21:01 356921 km -  N+   9h   Jan 16  1:54 406536 km +  F-   2h
Jan 30  9:59 357079 km -  N-  11h   Feb 12  5:11 406231 km +  F-2d18h
Feb 27 19:53 360438 km    N-1d12h   Mar 11 19:47 405365 km    F-4d21h
Mar 27 18:31 365705 km    N-3d 0h   Apr  8 14:53 404501 km    F-6d16h
Apr 23  0:28 369764 km    N-6d 5h   May  6 10:23 404318 km    N+7d 4h
May 18 11:59 367098 km    F+3d16h   Jun  3  4:26 404955 km    N+5d 9h
Jun 15  3:35 362061 km    F+1d23h   Jun 30 19:11 405931 km    N+3d10h
Jul 13  8:28 358258 km    F+  21h    Jul 28  3:28 406568 km -- N+1d 4h
Aug 10 17:44 356896 km ++ F-   0h   Aug 24  6:10 406522 km -  N-1d 8h
Sep  8  3:30 358387 km    F-  22h   Sep 20 14:23 405845 km    N-3d15h
Oct  6  9:42 362480 km    F-2d 1h   Oct 18  6:06 404897 km    N-5d15h
Nov  3  0:22 367870 km    F-3d22h   Nov 15  1:57 404336 km    N-7d10h
Nov 27 23:12 369824 km    N+5d10h   Dec 12 23:04 404583 km    F+6d10h
Dec 24 16:44 364790 km    N+2d15h   

Data Table Source: Lunar Perigee and Apogee Calculator. http://www.fourmilab.ch/earthview/pacalc.html
   

2014 Lunar Phases — Using U.S.A. Central Time (UT-6 or UT-5) 
      New Moon	           Full Moon	            
Jan. 1 We. 05:15 AM	Jan. 15 We. 10:53 PM	
Jan. 30 Th. 03:40 PM	Feb. 14 Fr. 05:54 PM	
Mar. 1 Sa. 02:02 AM	Mar. 16 Su. 12:10 PM	
Mar. 30 Su. 01:48 PM	Apr. 15 Tu. 02:45 AM	
Apr. 29 Tu. 01:17 AM	May 14 We. 02:18 PM	
May 28 We. 01:43 PM	June 12 Th. 11:13 PM	
June 27 Fr. 03:10 AM	July 12 Sa. 06:26 AM	
July 26 Sa. 05:42 PM	Aug. 10 Su. 01:10 PM	
Aug. 25 Mo. 09:13 AM	Sept. 8 Mo. 08:38 PM	
Sept. 24 We. 01:13 AM	Oct. 8 We. 05:50 AM	
Oct. 23 Th. 04:56 PM	Nov. 6 Th. 04:22 PM	
Nov. 22 Sa. 06:32 AM	Dec. 6 Sa. 06:27 AM	
Dec. 21 Su. 07:36 PM			    

Source of Lunar Phase Data: Moon Phases.

   
   
   
[centup]
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Super Moon x 3

 Graphic Credit: Heart Touching Fun (red-lined by me)

Graphic Credit: Heart Touching Fun (dates red-lined by me)

   File this under the ‘here we go again’ once again. Three “Super Moon” ‘events’ in a row – the next three months starting with the full Moon of July 12th; then August 10th; and then on September 9th. And I am hoping that this graphic will help in putting this into context.
   According to this graphic which was on Facebook about a year ago the full Moon of 23 June 2013 would be the largest appearing one of that year as well as the closest one for that year – a “Super Moon”. While the part about closest and largest appearing is correct, using the term “Super Moon” is misleading in the sense that there is nothing for comparison and so there will be folks going outside expecting to see a really large appearing full Moon. But how large? As large as the graphic suggests!!
   So what is a “Super Moon”; how “super” is it in comparison to other full Moons. And how significant, if at all, is this ‘event’?
   A “Super Moon” is a full Moon that occurs very near to its time of perigee, the closest the Moon comes to the Earth for that particular orbit, or month. By definition, “very close” would be when the Moon is less than 10% of its orbital period (about 2.9 days to 3.2 days) from the time of perigee. Use the data in the table below to compare the full and new Moon dates, with the apogee (farthest) and perigee dates and distances. Dates for apogee and perigee are given showing how many days and or hours before or after the date of the new or full moon these two distances occur.
   Here is an idea – use the apogee dates to determine when we will have a “Super Mini-Moon”!
The Full Moons of 2014

The Full Moons of 2014

   By comparing the dates and distances for this year, you will see that there are several “Super Moon”s in 2014. In fact, each year there are from four to six occurrences when the full Moon and perigee are close enough to be considered a “Super Moon” – the full Moon closest to the time for perigee is the actual “Super Moon” for that year. So a “Super Moon” is not that unique nor worthy of the hype these next three will receive other than drawing people’s attention to the night skies and our closest natural solar system neighbor.
   Carry this analysis further by comparing dates for full Moon and perigee over a several year period, and you’ll find a pattern in the regularity of “Super Moon” events. How? There are two regular time periods, or cycles, involved in the pattern for “Super Moon”. First, the time period between each full Moon, the synodic month, is approximately 29.53 days; second, the time period between each perigee, the anomalistic month, is approximately 27.55 days. With a two-day difference between these two cycles, there is obviously not a super Moon every month. However, with a ratio of 14 synodic months to 15 perigee periods,the closest of the “Super Moons” to perigee will occur about every 13-14 months. Because of the ratio relationship between these two cycles, 14 full Moons after the full Moon of June 23, 2013 (356,989 km), there will be the closest full Moon of 2014 on August 10th (356,896 km), which will be followed by the closest full Moon of September 28, 2015 (356,877 km), and so on.

   The above has been adapted from my October 2012 Scope on the Skies column in Science Scope Magazine “Apparent Sizes, or It Was This Big”. Click here to download a copy of that column (PDF).

                    
            
 (N=New Moon; F=Full Moon '-' = before; '+' = after)
           2014 - All times are shown in UT (Universal Time)
             Perigee                            Apogee
---------------------------------   ---------------------------------
Jan  1 21:01 356921 km -  N+   9h   Jan 16  1:54 406536 km +  F-   2h
Jan 30  9:59 357079 km -  N-  11h   Feb 12  5:11 406231 km +  F-2d18h
Feb 27 19:53 360438 km    N-1d12h   Mar 11 19:47 405365 km    F-4d21h
Mar 27 18:31 365705 km    N-3d 0h   Apr  8 14:53 404501 km    F-6d16h
Apr 23  0:28 369764 km    N-6d 5h   May  6 10:23 404318 km    N+7d 4h
May 18 11:59 367098 km    F+3d16h   Jun  3  4:26 404955 km    N+5d 9h
Jun 15  3:35 362061 km    F+1d23h   Jun 30 19:11 405931 km    N+3d10h
Jul 13  8:28 358258 km    F+  21h    Jul 28  3:28 406568 km -- N+1d 4h
Aug 10 17:44 356896 km ++ F-   0h   Aug 24  6:10 406522 km -  N-1d 8h
Sep  8  3:30 358387 km    F-  22h   Sep 20 14:23 405845 km    N-3d15h
Oct  6  9:42 362480 km    F-2d 1h   Oct 18  6:06 404897 km    N-5d15h
Nov  3  0:22 367870 km    F-3d22h   Nov 15  1:57 404336 km    N-7d10h
Nov 27 23:12 369824 km    N+5d10h   Dec 12 23:04 404583 km    F+6d10h
Dec 24 16:44 364790 km    N+2d15h   

Data Table Source: Lunar Perigee and Apogee Calculator. http://www.fourmilab.ch/earthview/pacalc.html
   

2014 Lunar Phases — Using U.S.A. Central Time (UT-6 or UT-5) 
      New Moon	           Full Moon	            
Jan. 1 We. 05:15 AM	Jan. 15 We. 10:53 PM	
Jan. 30 Th. 03:40 PM	Feb. 14 Fr. 05:54 PM	
Mar. 1 Sa. 02:02 AM	Mar. 16 Su. 12:10 PM	
Mar. 30 Su. 01:48 PM	Apr. 15 Tu. 02:45 AM	
Apr. 29 Tu. 01:17 AM	May 14 We. 02:18 PM	
May 28 We. 01:43 PM	June 12 Th. 11:13 PM	
June 27 Fr. 03:10 AM	July 12 Sa. 06:26 AM	
July 26 Sa. 05:42 PM	Aug. 10 Su. 01:10 PM	
Aug. 25 Mo. 09:13 AM	Sept. 8 Mo. 08:38 PM	
Sept. 24 We. 01:13 AM	Oct. 8 We. 05:50 AM	
Oct. 23 Th. 04:56 PM	Nov. 6 Th. 04:22 PM	
Nov. 22 Sa. 06:32 AM	Dec. 6 Sa. 06:27 AM	
Dec. 21 Su. 07:36 PM			    

Source of Lunar Phase Data: Moon Phases.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Super Moon – Super Bad Science

Graphic Credit: Heart Touching Fun

Graphic Credit: Heart Touching Fun

   File this under the ‘here we go again’ category on Facebook and other social media where this piece of misleading science is floating around.
   According to graphics like this one from Facebook and presumably re-posted and shared on other social media websites the full Moon of 23 June would be the biggest one this year as well as the closest one for the year – a “Super Moon”. So while the part about closest and largest is correct, using the term “Super Moon” is misleading in the sense that there is nothing for comparison and so there will be folks going outside expecting to see a really large appearing full Moon. But how large? As large as the graphic suggests!!
   So what is a “Super Moon”; how “super” is this next full Moon; and in comparison to other full Moons, how significant, if at all, is this ‘event’?
   A “Super Moon” is a full Moon that occurs very near to its time of perigee, the closest the Moon comes to the Earth for that particular orbit, or month. By definition, “very close” would be when the Moon is less than 10% of its orbital period (about 2.9 days to 3.2 days) from the time of perigee. Use the data in the table below to compare the full and new Moon dates, with the apogee (farthest) and perigee dates and distances. Dates for apogee and perigee are given showing how many days and or hours before or after the date of the new or full moon these two distances occur. The June 23rd perigee date is the same as the date for full Moon while the others are offset.
   Here is an idea – use the apogee dates to determine when we will have a “Super Mini-Moon”!
The 2013 Full Moon

The 2013 Full Moons

   By comparing the 23 June distance with other dates and distances, you will see that there are several “Super Moon”s in 2013. In fact, each year there are from four to six occurrences when the full Moon and perigee are close enough to be considered a “Super Moon” – the full Moon closest to the time for perigee is the “Super Moon” for that year. So a “Super Moon” is not that unique nor worthy of the hype this one will receive since we can have several “Super Moon” ever year.
   Carry this analysis further by comparing dates for full Moon and perigee over a several year period, and you’ll find a pattern in the regularity of “Super Moon” events. How? There are two regular time periods, or cycles, involved in the pattern for “Super Moon”. First, the time period between each full Moon, the synodic month, is approximately 29.53 days; second, the time period between each perigee, the anomalistic month, is approximately 27.55 days. With a two-day difference between these two cycles, there is obviously not a super Moon every month. However, with a ratio of 14 synodic months to 15 perigee periods,the closest of the “Super Moons” to perigee will occur about every 14 months. Because of this ratio relationship between these two cycles, 14 full Moons after the full Moon of June 23, 2013 (356,989 km), there will be the closest full Moon of August 10, 2014 (356,896), which will be followed by the closest full Moon of September 28, 2015 (356,877 km), and so on.

   The above has been adapted from my October 2012 Scope on the Skies column in Science Scope Magazine “Apparent Sizes, or It Was This Big”. Click here to download a copy of that column (PDF).

                    
             Perigee                             Apogee
     (N=New Moon; F=Full Moon '-' = before; '+' = after)
           All times are shown in UT (Universal Time)
Jan 10 10:27 360047 km    N-1d 9h   Jan 22 10:53 405311 km    F-4d17h
Feb  7 12:10 365313 km    N-2d19h   Feb 19  6:31 404473 km    F-6d13h
Mar  5 23:21 369953 km    N-5d20h   Mar 19  3:14 404261 km    N+7d 7h
Mar 31  3:56 367493 km    F+3d18h   Apr 15 22:23 404864 km    N+5d12h
Apr 27 19:49 362267 km    F+1d23h   May 13 13:32 405826 km    N+3d13h
May 26  1:46 358374 km    F+  21h   Jun  9 21:41 406486 km -  N+1d 5h
Jun 23 11:11 356989 km ++ F-   0h   Jul  7  0:37 406491 km -- N-1d 6h
Jul 21 20:28 358401 km    F-  21h   Aug  3  8:54 405833 km    N-3d12h
Aug 19  1:27 362264 km    F-2d 0h   Aug 30 23:47 404882 km    N-5d11h
Sep 15 16:35 367387 km    F-3d18h   Sep 27 18:18 404308 km    N-7d 6h
Oct 10 23:07 369811 km    N+5d22h   Oct 25 14:26 404560 km    F+6d14h
Nov  6  9:29 365361 km    N+2d20h   Nov 22  9:51 405445 km    F+4d18h
Dec  4 10:16 360063 km    N+1d 9h   Dec 19 23:50 406267 km +  F+2d14h

   

  Date/Time of New Moon   Date/Time of Full Moon
   2013 Jan 11 19:45        2013 Jan 27  4:40
   2013 Feb 10  7:23        2013 Feb 25 20:29
   2013 Mar 11 19:54        2013 Mar 27  9:30
   2013 Apr 10  9:39        2013 Apr 25 20:00
   2013 May 10  0:32        2013 May 25  4:27
   2013 Jun  8 15:59        2013 Jun 23 11:34
   2013 Jul  8  7:16        2013 Jul 22 18:17
   2013 Aug  6 21:52        2013 Aug 21  1:45
   2013 Sep  5 11:36        2013 Sep 19 11:13
   2013 Oct  5  0:34        2013 Oct 18 23:38
   2013 Nov  3 12:50        2013 Nov 17 15:17
   2013 Dec  3  0:22        2013 Dec 17  9:29     

Data Table Source: Lunar Perigee and Apogee Calculator. http://www.fourmilab.ch/earthview/pacalc.html

   Click here to go to the Qué tal in the Current Skies web site for more observing information.