Though the alignment isn't once-in-a-lifetime rare, the seven other planets in our solar system don't align every year, so it can be a spectacle to witness.Start the day smarter. Get all the news you need in your inbox each morning.

Mercury is joining Venus, Mars, Jupiter, Saturn, Uranus, and Neptune for a seven-planet parade. It's a stargazer's paradise.

Houstonians will be able to see seven planets in the sky this weekend in what's called a planetary parade. Unfortunately, however, some may not be spotted with the naked eye. Just after dark, it will be possible to view Mercury,