According to NASA, multi-planet lineups are visible "every few years," but a seven-planet alignment is particularly uncommon, as each planet's orbit varies, with some moving more quickly and Mercury, in particular, being visible during its 88-day orbit for only "a couple of weeks at a time" each year.

While much of what you've been hearing about a "Planetary Parade," is pure hype, you still do have reason to look into the night sky Sunday.