When are the next ring plane crossings after those in 1995-96?
- Sep 04, 2009 (only one Earth-crossing)
- Aug 10, 2009 (Sun-crossing)
- Mar 23, 2025 (only one Earth-crossing)
- May 06, 2025 (Sun-crossing)
When were the last ring plane crossings?
- Oct 27, 1979 04h UT (Earth-crossing 1)
- Mar 03, 1980 04h UT (Sun-crossing)
- Mar 12, 1980 13h UT (Earth-crossing 2)
- Jul 23, 1980 05h UT (Earth-crossing 3)
Source: TENMON NENKAN 1980 (TENMON NENKAN, handy/popular
Japanese Astronomical Ephemeris)
Original data from the American Ephemeris 1980.
Here is more on the ring plane crossings.
Richard Hill sent me
this message giving a
description of what he
saw during the last two rings plane crossings and
what one might expect to see when the Sun crosses the
ring plane.
There is some interesting
discussions about passages of the Earth through the ring-plane
in a book called "The Planet Saturn: A History of Observation,
Theory and Discovery" by A.F.O'D. Alexander. The book gives
some detailed observation notes from previous "disappearances"
of the rings.
Some early observers reported seeing "knots" in the rings when they
were nearly edge-on and some expected to see some strange
effects when the Sun crossed the ring-plane.
The books says:
- There may be 1 or 3 Earth crossings (there most be an odd number)
during any half-orbit of Saturn (15 years).
- If there is only one Earth crossing then Saturn and the Earth
will be on almost opposite sides of the Sun; hence making observations
difficult.
- If there are three crossings, the middle one is near opposition
and the other two are near quadratures.
- The chance of three intersections is about 53% and the chance of
one intesection is about 47%.
- There is an occasional case where the Earth hangs in the plane without
passing through it.
In 1936-1937 there were sort of only two Earth "crossings". On 1937-Feb-20
the Earth did cross the ring plane. On 1936-Jun-28 the Earth did not cross
the ring plane, but did get close to it - the Saturnicentric latitude of
the Earth being only 0.0001 degrees! The Sun crossed the ring plane on
1936-Dec-28.
Return to Saturn Events