Earth takes 365 days to travel one complete orbit, while Mercury takes 88 days and Venus takes 224 days, so the time between alignments will require each planet to make a whole number of orbits around the sun and return to the pattern you see in the figure above.
Beside this, what are the orbits of the planets?
The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury are very nearly circular. The orbits of the planets are all more or less in the same plane (called the ecliptic and defined by the plane of the Earth's orbit).
What is the period of rotation for each planet?
The Days (And Years) Of Our Lives
|Planet||Rotation Period||Revolution Period|
|Mercury||58.6 days||87.97 days|
|Venus||243 days||224.7 days|
|Earth||0.99 days||365.26 days|
|Mars||1.03 days||1.88 years|
Can the orbits of the planets change?
If the Sun and Earth were the only things in the solar system, our planet's orbit would be an ellipse of virtually constant shape and orientation in space. However, because the other planets pull on Earth, our orbit does change slightly over time, in orientation and in shape. Same for the other planets' orbits.