[AZ-Observing] Mars
- From: "Randy Peterson" <rgpeterson@xxxxxxx>
- To: "AZ Observing" <az-observing@xxxxxxxxxxxxx>
- Date: Thu, 28 Aug 2003 09:19:52 -0700
----- Original Message -----
From: <afls@xxxxxxx>
To: <rgpeterson@xxxxxxx>
Cc: <afls@xxxxxxx>
Sent: Thursday, August 28, 2003 9:14 AM
Subject: please post ot AZ observing list
These next two weeks Mars will cause Earth tides of up to an extra 4 cm
(1.75 inches) at Rocky Point, Mexico and 6 cm (2 inches) at the Bay of
Fundy, in eastern Canada.
Now that Mars is at record close approach to Earth you may be interested to
know that Mars has a subtle tidal effect on the Earth. Tides are caused by
the differing gravitational strength on the near, center, and far sides of
the Earth. Generally each day, ocean tides are highest on Earth's near and
far sides and lowest at the middle distance from a celestial body. The Moon
causes the greatest tides because it is so close, only 383,000 km (238,000
miles) away. The Sun also causes significant tides because of its greater
mass.
On Earth, where there are large closed bays to funnel water, tides can
become quite high. Two prime examples are the Gulf of Baja California in
Mexico, where Rocky Point is a common destination of Arizonans and the Bay
of Fundy, Canada. Mars will cause the greatest tidal effect at these
locations as well. At the Bay of Fundy when the Moon is New or Full
combined tides with the Sun can reach 13.71 m (45 ft). Today, August 27th,
is New Moon AND Mars is closest to the Earth; the tide should be 13.77m 45
ft 2 in)!
The Mars, Moon, Sun tidal pull should also be at its greatest in 59,619
years. In fact, unless the Moon was New of Full exactly on that date of
Mars' closest approach 59,619 years ago this record tidal effect may be many
thousands of years longer.
The planet Venus also causes significant Earth tides when it is at its
inferior conjunction distances of 38,000,000 to 42,000,000 km (24,000,000 -
26,000,000 miles). At the Bay of Fundy tides can be an additional 12 cm (5
in).
Bill Peters
--
See message header for info on list archives or unsubscribing, and please
send personal replies to the author, not the list.
Other related posts:
