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)
Orbital periods can change. Hale-Bopp's orbital period changed from 4,206 years to 2,380 years following a relatively close approach to Jupiter. The planet's gravity altered the comet's orbit so that it won't take Hale-Bopp as long to return on its next visit. Look for it again in the year 4377.