It is convenient to draw planet configuration with following data.
Revolution of planetsEdit
Table of synodic periods in the Solar System, relative to Earth:
Sid. P. (a) Syn. P. (a) Syn. P. (d) Mercury 0.241 0.317 115.9 Venus 0.615 1.599 583.9 Earth 1 — — Moon 0.0748 0.0809 29.5306 Mars 1.881 2.135 780.0 4 Vesta 3.629 1.380 504.0 1 Ceres 4.600 1.278 466.7 10 Hygiea 5.557 1.219 445.4 Jupiter 11.87 1.092 398.9 Saturn 29.45 1.035 378.1 Uranus 84.07 1.012 369.7 Neptune 164.9 1.006 367.5 134340 Pluto 248.1 1.004 366.7 136199 Eris 557 1.002 365.9 90377 Sedna 12050 1.00001 365.1
Superior and inferiorEdit
As seen from a planet that is superior, if an inferior planet is on the opposite side of the Sun, it is in superior conjunction with the Sun. An inferior conjunction occurs when the two planets lie in a line on the same side of the Sun. In an inferior conjunction, the superior planet is "in opposition" to the Sun as seen from the inferior planet.
The terms "inferior conjunction" and "superior conjunction" are used in particular for the planets Mercury and Venus, which are inferior planets as seen from the Earth. However, this definition can be applied to any pair of planets, as seen from the one further from the Sun.
A planet (or asteroid or comet) is simply said to be in conjunction, when it is in conjunction with the Sun, as seen from the Earth. The Moon is in conjunction with the Sun at New Moon (or rather Dark Moon).
"Quasi-conjunctions" are also possible; in this scenario, a planet in retrograde motion — always either Mercury or Venus — will "drop back" in right ascension until it almost allows another planet to overtake it, but then the former planet will resume its forward motion and thereafter appear to draw away from it again. This will occur in the morning sky, before dawn; or the reverse may happen in the evening sky after dusk, with Mercury or Venus entering retrograde motion just as it is about to overtake another planet (often Mercury and Venus are both of the planets involved, and when this situation arises they may remain in very close visual proximity for several days or even longer). The quasi-conjunction is reckoned as occurring at the time the distance in right ascension between the two planets is smallest, even though, when declination is taken into account, they may appear closer together shortly before or after this.
- Earthquake prediction
- Orbital period
- Conjunction (astronomy)
- Planet moon
- Distance of planets
- Distance of satellites
Earthquake prediction by geometric relationship of planets, moon, and sun.