Syzygy (astronomy)
In
The word is often used in reference to the
. The term is often applied when the Sun and Moon are in conjunction (new moon) or opposition (full moon).[3]When Earth is one of the bodies involved, the other objects appear to be close together (or overlapping) in the sky.
Main types
A syzygy sometimes results in an occultation, transit, or an eclipse.
- An occultation occurs when an apparently larger body passes in front of an apparently smaller one.
- A transitoccurs when a smaller body passes in front of a larger one.
- In the combined case where the smaller body regularly transits the larger, an occultation is also termed a secondary eclipse.
- An eclipse occurs when a body totally or partially disappears from view, either by an occultation, as with a solar eclipse, or by passing into the shadow of another body, as with a lunar eclipse (thus both are listed on NASA's eclipse page).
Consequences
Einstein ring
As electromagnetic rays are affected by gravitation, when they pass by a heavy mass they are bent. As a result, the heavy mass acts as a form of gravitational lens. If the light source, the gravitating mass and the observer stand in a line, one sees what is termed an Einstein ring.
Tidal variation
A syzygy causes the fortnightly phenomena of
Extraterrestrial cases
The word syzygy is often used to describe interesting configurations of astronomical objects in general. For example, one such case occurred on March 21, 1894, around 23:00
On June 3, 2014, the
Other uses
The term is also used to describe situations when all the planets are on the same side of the Sun although they are not necessarily in a straight line, such as on March 10, 1982.[7]
Because the orbits of all the planets in the Solar System (as well as the Moon) are inclined by only a few degrees, they always appear very near the
References
- CollinsDictionary.com. HarperCollins. Retrieved 22 August 2012.
- ^ "Syzygy". Glossary, The Astronomical Almanac Online. HM Nautical Almanac Office and United States Naval Observatory. 2012. Archived from the original on 2013-06-15. Retrieved 2012-09-13.
- . Retrieved May 5, 2012.
- ^ "Three Planets Dance Over La Silla". ESO Picture of the Week. Retrieved 5 June 2013.
- ^ Matt Rosenberg. "Tides: The Sun and Moon Affect the Oceans". Retrieved May 10, 2012.
- ^ a b Webster, Guy (June 10, 2014). "Mercury Passes in Front of the Sun, as Seen From Mars". NASA. Retrieved June 10, 2014.
- ^ "Ideas & Trends in Summary; It's All Right To Come Out Now". New York Times. March 14, 1982. Retrieved May 20, 2015.