1 more sidereal month than synodic month
The length of one sidereal Earth year is 3.39% the length of one sidereal Saturn year. In other words, the length of one sidereal Saturn year is 29.5 times the length of one sidereal Earth year. (A sidereal year is the time between alignments of the sun, the planet, and a distant fixed star.)
Venus. The "day" (rotation period or sidereal day) is longer than the year! Venus Sidereal day: 243 Earth days. Venus Year: 224.7 Earth days.
The length of a Martian day is equal to 1.027491204 Earth days. The length of one sidereal Martian year is equal to 1.880791 sidereal Earth years.
1 day is 1/365.25636 of a sidereal year.
lunar year:354.37 days Tropical year (solar year): 365.24219 days sidereal year: 365.25636042
Mercury has the 2nd longest "sidereal day" with a sidereal rotation period of 58.646 Earth days. The longest "sidereal day" day is Venus, with a sidereal rotation period of 243.018 Earth daysIf you use the "solar day" as your definition of "day", the order is reversed. Mercury then has the longest day and Venus has the second longest day.
Mars with 1.8807 sidereal years.
321.7 sidereal days.
Earth's sidereal period is 1 year or about 365.25 days ========= Whoever posted the previous answer shouldnt have wasted their time propagating lies and stupidity. What a moron who posts answers when they should know that they dont even know the answer. The Earth's Sidereal Period is 366.242 days, approximately.
A sidereal year is measured based on the planet's position in space relative to the background stars. A synodic year is measured based on the planet's position relative to the star it rotates around (i.e. the sun) Here's an image that is pretty helpful in visualizing.
Sidereal is a term used to refer to the apparent motion of the stars. An example sentence is: The sidereal was fantastic.