Astronomy/Equinoxes

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Expert: - 9/24/2004


Question
I have noticed that the solstices and equinoxes seem to be falling on the 22nd of the month lately rather than the 21st as in earlier years.  Is this a peculiarity of our calendar, the orbit of the earth, or something else?

Answer
Hi Mary Ellen,
I would have answered much sooner, but the AllExperts
website has been down.

Well, I know its not the Earth or anything concerning the
Solar system....we are like a rotating gyroscope which is
locked into its correct orientation....admittedly slowing down
our rotation rate like 37 micro-seconds per year, but not enough to notice a change during one's short lifetime.

It's actually our calendar Mary Ellen....we can't add 1/4 day
every year...we have to wait 4 years, then add a whole day,
the leap year....so our calendar can get out of step by 3/4
(3 times 1/4), of a day before a leap year.  This is why some years the first day of Spring is March 21, and others March 22nd....and same holds true for the other cardinal points in space that you mentioned.  In fact, the Autumnal Equinox can
occur as late as Sept 23rd!

Same happens for the other fixed points in space, say the
Perseid meteor shower, always the night of....usually,
August 11th.  But in a year before a leap year, 2003,
2007, 2011, etc. that point in space falls on the night of
August 12th on our 'delayed' calendar!  So its not the Earth, Space, or anything else; it's our own calendar and that 1/4 day we can't add in, every year.

Hope this helps, and for any other astronomical question,
feel free to contact me directly at bwhiting@velocity.net
if you wish.
Clear Skies,
Tom Whiting
Pres...ECMOG
Erie, PA

Also, please visit our club website for great pictures
of my new 30 inch portable scope, at
http://www.velocity.net/~bwhiting/

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Tom Whiting

Expertise

Astronomy has been my hobby/pasttime for over 50 years.  Currently own 3 telescopes, the largest of which is a 30 inch Newtonian truss Dob that is portable.I taught Astronomy/Meteorology at the University Level for 13 years before retiring in 1995. Being retired and home most of the time, I am able to answer all questions relatively quickly, unless it's a new moon weekend with good observing conditions.  No astrology questions please, or questions about alleged UFO picture identifications.

Experience

Experience: Astronomy has been my hobby and study for over 50 years. We currently now own a 30 inch portable telescope (Updated - Pennsylvania`s largest portable telescope). It can be seen on our website at:http://www.velocity.net/~bwhiting and also attend several regional starparties during the year, and have been on 5 total solar eclipse expeditions.

Organizations: President, Erie County Mobile Observers Group for over 15 years.

Publications: Wrote the "Over Erie Skies" newspaper article in our local newspaper for 11 years (1975-86).

Education: Masters Degree- Taught at the University level for 13 years. Retired 20 years -USAF Pilot - KC-135 with 180 combat missions;  Also Eagle Scout, Philmont staff 2 Yrs, Order of Arrow Lodge Chief, Ham Radio (inactive).

Awards: two discoveries: The mini-coathanger asterism in Ursa Minor (the little dipper) And the mini-ladle- another asterism in the bowl of Ursa Minor. Clients: Currently President of the ECMOG as mentioned above.

Education/Credentials
BS  Metallurgical Engineering Grove City College, PAMaster's Degree, Gannon University, Erie, PA Also retired USAF pilot, 20 years.

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