There is a perigee moon every month, and once a year it is near the time of full moon. The difference between a perigee full moon and an apogee full moon is noticeable when you compare images side by side, but without comparison you can’t tell the difference.
In the case of a perigee new moon and apogee new moon the difference becomes apparent in eclipses… Like the one on May 20th. We see an annular eclipse because the moon is near apogee, if it were near perigee we would see a total eclipse, as Australians will in November. Here size matters, but with a full moon in the night sky? Perigee and apogee discussions belong with eclipses, not full moons.
When I hear the news reports about the Super Moon I know that potential stargazers are being set up for a disappointment. It wouldn’t be the first time. I was suckered in with the “Comet of the Century” – Comet Kohoutek – back in the ’70s. I passed along exaggerated information – then I went out to see the comet low in the sunset sky. It was there,
but it was not the “Comet of the Century”.
Do you remember the claims of Mars appearing as big as the full moon? Disappointed public and a loss of credibility.
I post astronomical events on our museum website. What I post is the moon phases, when the moon is passing a bright planet, and when to look for shooting stars. I get the dates from the RASC Handbook, and then I check the visibility with Starry Night before posting. I will not tell someone about something they can not see. If I disappoint them, I lose credibility.
I have held back on sensational claims, maybe a little more than I should and then again, maybe not. I would rather tell someone that the best time to look at the moon with binoculars is near first quarter because you can see craters along the boundary between day and night – it is something they actually can see. At star parties, I set the telescope on bright clusters or planets, not galaxies so dim you need to know about using averted vision to get a hint that they are in the field of view. The viewers leave the telescope excited by what they saw.
There are some events that are more difficult to see, but are significant because they really are rare – June’s Transit of Venus falls into this category. The average person does not have the ability to see this event on their own – but a planetarium, museum, or astronomy club hosted viewing session can offer the opportunity to see the event.
It’s time to get real about what we claim as astronomically significant events. Now I have to go run a show about how to find constellations using a star map.