The date of this document is unknown.

K.E. Chilton—Centennial Observatory
93 Currie St.,
Hamilton Ont.

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POSSIBLE MAGNITUDE VARIATIONS OF SATURN'S SATELLITES

by K.E. Chilton, Planetary Coordinator

For many years it has been known that he magnitude of Iapetus, Saturn's outermost moon, is variable. Recent observations have indicated that some of the other moons may vary in brightness, too. (Refs. 1,2) This was pointed out in Planetary Bulletin No.9. However, observers were left ot their own devices to work out the positions of the satellites.

OFFICIAL OBSERVING PROGRAMME

The Royal Astronomical Society of Canada
Hamilton Centre

Notice: This book is the property of the Hamilton Centre and is being loaned to you to stimulate interest in observing and to help you make observations of scientific value.

CENTENNIAL OBSERVATORY

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Hamilton 57, Ont.,
Canada

SEMI*ANNUAL REPORT
January-June 1969

Members of

THE
ROYAL ASTRONOMICAL SOCIETY
OF CANADA

252 College Street - Toronto 2B, Ontario

FOR USE OF MEMBERS ONLY

Permission for use of this membership
list for other purposes must be obtained
from the National Office

1958 September 30

Document date > 1968 Oct 31

by K.E. Chilton

Is the Moon a cold, lifeless, changeless body? Or, are there changes from time to time? Recently, there has been much interest in amateur astronomical circles, in investigating changes on the Moon which seem to be of a transitory or impermanent nature.

by K.E. Chilton

This was written to augment a talk by Robert G. Speck to the Discussion Group of the Hamilton Centre of the Royal Astronomical Society of Canada on April 22, 1976.

PRE-MARINER FINDINGS

Three main cloud types have been distinguished in the thin, dry, cold Martian atmosphere: white, blue and yellow clouds, so named for the colours which they predominantly reflect.

White Clouds:

White clouds vary considerably in thickness, brilliance and extent. They can be subdivided into three categories: