Whenever the subject of mosquito control comes up, someone gives a fervent argument for installing purple martin houses and bat houses. Stores that cater to bird enthusiasts often tout the purple martin houses as the best solution for keeping your yard mosquito free.
A short period comet is conventionally defined as a comet having an orbital period of less than 200 years. What is the maximum possible aphelion distance for a short period comet with a perihelion of 0.5 AU? Where does this place the comet relative to the outer planets? (3)
In fact, the length of the lunar month from one new Moon to the next (or from one full Moon to the next) is 29.53 days, but the Moon's orbital period is actually 2.21 days shorter (this is discussed in the section on the calendar).