Mercury will join Mars, Jupiter, Uranus, Neptune, Venus and Saturn in the night sky in a phenomenon that will not be seen again until 2040

Prepare for an unforgettable 'parade of planets' as 7 planets will align in a rare celestial event on Feb. 28, for the last time in a decade. Some will be visible to the naked eye, while others may require a closer look through a telescope.

Skywatchers in the United States get the chance to observe a rare planetary parade tonight. Seven planets will align just after sunset, though not all will be visible to the naked eye. Viewing conditions will be optimal in areas with dark skies and an unobstructed western horizon.