Planets are wanderers . . .
Is this first impression misleading?
Is this first impression misleading?
I am often delighted by finding that the derivation of a word helps me understand it and use it better. This time I am not happy.
It was useful to call
a planet a wanderer a few thousand years ago, when the earth was so obviously
flat. And yes, Sirius the Dog Star stayed faithful to Orion, while these
planets roamed at different speeds, sometimes sharp eyes even see them go
backwards.
But then there was an
eclipse and they realised the Earth was round.
And over a few more
months it was seen that wander was not such a good word. True, planets moved.
But it was soon recognised that they were all on the same line and in the same
direction AND the different speeds told us that they orbit at different
distances, all much closer than any star.
If “wander” means
1. To proceed in an irregular course; meander;
or
2. To go astray,
The "wanderer" concept was out of date 3000
years ago.
This familiar view
can not be seen from earth
From
Earth, the planets make a procession along the path taken by the Sun. . The
fastest is the closest , so the moon glides from planet to planet, to repeat
its path a month later. The moon rises at sunset every 29 days. Mars does this
every two years. Saturn takes 30 years to line up in front of eg Scorpio twice,
when viewed from here. View a coin edge on and it is linear, like the Solar
System. Irregular? Astray?
WE SET OUR CLOCKS BY THE SKY
WE SET OUR CLOCKS BY THE SKY
I’ll
post a calendar ready for February, when Venus is seen starting a rush across
the evening sky for a conjunction with Jupiter, with the dates of each time it
passes a planet. This Highway of the Sky is called the “Ecliptic” because there
are 4 eclipses on it most years.February to June next year is a great period for planet watching!
