[AZ-Observing] Re: Seeing Scale Simulation

Thad!

Is this the 12-point Pickering scale you were referring to? It was
devised by W.H. Pickering and has 12 points... maybe he did finish it,
well maybe not. It is a test of visual acuity and goes in increasing
order of difficulty. It's from an article in the June 97 Astronomy (p.
82) on naked-eye Moon observing!

1.  Bright surroundings of Copernicus

2.  Mare Nectaris

3.  Mare Humorum

4.  Bright surroundings of Kepler

5.  Region of Gassendi

6.  Notch in the Mare Tranquillitatis-Plinius region

7.  Mare Vaporum

8.  Light area around crater Lubiniezky

9.  Sinus Medii

10.  Shaded area near the walled plain Sacrobosco

11.  Dark spot at the foot of the Apennines

12.  Riphaeus Mountains

William H. Pickering (1858-1938), little brother and assistant to E.C.
Pickering (1846-1919), long-time director of Harvard College
Observatory. (Just like Brian said.) Warning: The last two may not be
humanly possible (I will cheat with binoculars). The Pickerings were
noted for possesing excellent vision, as good as E.E. Barnard or (so he
says) Steven James O'Meara. :-)

FYI, Brian's reference of the Antoniadi scale, which is usually used for
the Moon and planets:

ANTONIADI SCALE:

I. Perfect seeing, without a quiver.

II. Slight undulations, with moments of calm lasting several seconds.

III. Moderate seeing, with large tremors.

IV. Poor seeing, with constant troublesome undulations.

V. Very bad seeing, scarcely allowing the making of a rough sketch.

Jack Jones
Saguaro Astronomy Club
Lunar List Awards and
Messier Marathon Co-coordinator
Phoenix AZ
spicastar@xxxxxxxxxxxxxxx


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