But the advice is mixed for summer flights. âI would suggest buying your airfares for summer as soon as you can,â said Krista Pappas, global travel industry director for Bing, citing high fuel prices, tight seating capacity and strong consumer demand as a recipe for rising rates.
A sidereal period is also defined as the position of an object with respect to the stars. The synodic month is a bit longer than the sidereal month. When a synodic month lasts 29 days, 12 hours, and 44 minutes, a sidereal month lasts 27 days, 7 hours, and 43 minutes.
A sidereal year is the time it takes for the sun to return to the same position with respect to the stars. Due to the precession of the equinoxes the sidereal year is about 20 minutes longer than the tropical year. The tropical year is the interval at which seasons repeat and is the basis for the calendar year.